From bd046b99f03811f992571c47c47f2cecfe38df0c Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Mon, 19 Jan 2004 21:20:06 +0000 Subject: [PATCH] Remove JDBC from the build system and documentation, too. --- GNUmakefile.in | 4 +- README | 8 +- aclocal.m4 | 3 +- config/java.m4 | 61 - configure | 150 -- configure.in | 19 +- doc/src/sgml/filelist.sgml | 3 +- doc/src/sgml/installation.sgml | 47 +- doc/src/sgml/jdbc.sgml | 3197 -------------------------------- doc/src/sgml/postgres.sgml | 3 +- src/Makefile.global.in | 5 +- src/interfaces/Makefile | 8 +- src/makefiles/Makefile.cygwin | 4 +- 13 files changed, 15 insertions(+), 3497 deletions(-) delete mode 100644 config/java.m4 delete mode 100644 doc/src/sgml/jdbc.sgml diff --git a/GNUmakefile.in b/GNUmakefile.in index bcc157bc2f..5f7e6558de 100644 --- a/GNUmakefile.in +++ b/GNUmakefile.in @@ -1,7 +1,7 @@ # # PostgreSQL top level makefile # -# $PostgreSQL: pgsql/GNUmakefile.in,v 1.36 2003/11/28 20:32:09 pgsql Exp $ +# $PostgreSQL: pgsql/GNUmakefile.in,v 1.37 2004/01/19 21:20:04 tgl Exp $ # subdir = @@ -72,7 +72,7 @@ $(distdir).tar: distdir opt_files := \ src/tools src/corba src/tutorial \ src/bin/pgtclsh \ - $(addprefix src/interfaces/, libpgtcl jdbc) \ + $(addprefix src/interfaces/, libpgtcl) \ $(addprefix src/pl/, plperl plpython tcl) docs_files := doc/postgres.tar.gz doc/src doc/TODO.detail diff --git a/README b/README index 22607bb6f6..923e951a8c 100644 --- a/README +++ b/README @@ -8,11 +8,11 @@ PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains several language -bindings, including C, Perl, Python, and Tcl, as well as a JDBC -driver. +bindings, including C and Tcl. -The ODBC and C++ interfaces have been moved to the PostgreSQL Projects -Web Site at http://gborg.postgresql.org for separate maintenance. +The JDBC, ODBC, C++, and Python interfaces have been moved to the PostgreSQL +Projects Web Site at http://gborg.postgresql.org for separate maintenance. +A Perl DBI/DBD driver is available from CPAN. See the file INSTALL for instructions on how to build and install PostgreSQL. That file also lists supported operating systems and diff --git a/aclocal.m4 b/aclocal.m4 index 1fd7537db7..496f806f96 100644 --- a/aclocal.m4 +++ b/aclocal.m4 @@ -1,10 +1,9 @@ -dnl $PostgreSQL: pgsql/aclocal.m4,v 1.16 2003/11/29 19:51:16 pgsql Exp $ +dnl $PostgreSQL: pgsql/aclocal.m4,v 1.17 2004/01/19 21:20:04 tgl Exp $ m4_include([config/ac_func_accept_argtypes.m4]) m4_include([config/c-compiler.m4]) m4_include([config/c-library.m4]) m4_include([config/docbook.m4]) m4_include([config/general.m4]) -m4_include([config/java.m4]) m4_include([config/libtool.m4]) m4_include([config/perl.m4]) m4_include([config/programs.m4]) diff --git a/config/java.m4 b/config/java.m4 deleted file mode 100644 index 1bfcf31dfb..0000000000 --- a/config/java.m4 +++ /dev/null @@ -1,61 +0,0 @@ -# -# Autoconf macros for configuring the build of Java JDBC Tools -# -# $PostgreSQL: pgsql/config/java.m4,v 1.5 2003/11/29 19:51:17 pgsql Exp $ -# - - -# _PGAC_PROG_ANT_WORKS -# -------------------- -AC_DEFUN([_PGAC_PROG_ANT_WORKS], -[ - AC_CACHE_CHECK([whether $ANT works], [pgac_cv_prog_ant_works], - [ - cat > conftest.java << EOF -public class conftest { - int testmethod(int a, int b) { - return a + b; - } -} -EOF - - cat > conftest.xml << EOF - - - - - - -EOF - - pgac_cmd='$ANT -buildfile conftest.xml 1>&2' - AC_TRY_EVAL(pgac_cmd) - pgac_save_status=$? - if test $? = 0 && test -f ./conftest.class ; then - pgac_cv_prog_ant_works=yes - else - echo "configure: failed java program was:" >&AS_MESSAGE_LOG_FD - cat conftest.java >&AS_MESSAGE_LOG_FD - echo "configure: failed build file was:" >&AS_MESSAGE_LOG_FD - cat conftest.xml >&AS_MESSAGE_LOG_FD - pgac_cv_prog_ant_works=no - fi - - rm -f conftest* core core.* *.core - ]) - - if test "$pgac_cv_prog_ant_works" != yes; then - AC_MSG_ERROR([ant does not work]) - fi -]) - - -# PGAC_PATH_ANT -# ------------- -# Look for the ANT tool and set the output variable 'ANT' to 'ant' -# if found, empty otherwise -AC_DEFUN([PGAC_PATH_ANT], -[ - AC_PATH_PROGS(ANT, [jakarta-ant ant ant.sh ant.bat]) - _PGAC_PROG_ANT_WORKS -]) diff --git a/configure b/configure index 828ac5c60b..3c23e6647e 100755 --- a/configure +++ b/configure @@ -864,7 +864,6 @@ Optional Packages: --with-tkconfig=DIR tkConfig.sh is in DIR --with-perl build Perl modules (PL/Perl) --with-python build Python modules (PL/Python) - --with-java build JDBC interface and Java tools --with-krb4 build with Kerberos 4 support --with-krb5 build with Kerberos 5 support --with-krb-srvnam=NAME name of the service principal in Kerberos [postgres] @@ -3166,153 +3165,6 @@ echo "$as_me:$LINENO: result: $with_python" >&5 echo "${ECHO_T}$with_python" >&6 -# -# Optionally build the Java/JDBC tools -# -echo "$as_me:$LINENO: checking whether to build Java/JDBC tools" >&5 -echo $ECHO_N "checking whether to build Java/JDBC tools... $ECHO_C" >&6 - - - -# Check whether --with-java or --without-java was given. -if test "${with_java+set}" = set; then - withval="$with_java" - - case $withval in - yes) - echo "$as_me:$LINENO: result: yes" >&5 -echo "${ECHO_T}yes" >&6 - - for ac_prog in jakarta-ant ant ant.sh ant.bat -do - # Extract the first word of "$ac_prog", so it can be a program name with args. -set dummy $ac_prog; ac_word=$2 -echo "$as_me:$LINENO: checking for $ac_word" >&5 -echo $ECHO_N "checking for $ac_word... $ECHO_C" >&6 -if test "${ac_cv_path_ANT+set}" = set; then - echo $ECHO_N "(cached) $ECHO_C" >&6 -else - case $ANT in - [\\/]* | ?:[\\/]*) - ac_cv_path_ANT="$ANT" # Let the user override the test with a path. - ;; - *) - as_save_IFS=$IFS; IFS=$PATH_SEPARATOR -for as_dir in $PATH -do - IFS=$as_save_IFS - test -z "$as_dir" && as_dir=. - for ac_exec_ext in '' $ac_executable_extensions; do - if $as_executable_p "$as_dir/$ac_word$ac_exec_ext"; then - ac_cv_path_ANT="$as_dir/$ac_word$ac_exec_ext" - echo "$as_me:$LINENO: found $as_dir/$ac_word$ac_exec_ext" >&5 - break 2 - fi -done -done - - ;; -esac -fi -ANT=$ac_cv_path_ANT - -if test -n "$ANT"; then - echo "$as_me:$LINENO: result: $ANT" >&5 -echo "${ECHO_T}$ANT" >&6 -else - echo "$as_me:$LINENO: result: no" >&5 -echo "${ECHO_T}no" >&6 -fi - - test -n "$ANT" && break -done - - - echo "$as_me:$LINENO: checking whether $ANT works" >&5 -echo $ECHO_N "checking whether $ANT works... $ECHO_C" >&6 -if test "${pgac_cv_prog_ant_works+set}" = set; then - echo $ECHO_N "(cached) $ECHO_C" >&6 -else - - cat > conftest.java << EOF -public class conftest { - int testmethod(int a, int b) { - return a + b; - } -} -EOF - - cat > conftest.xml << EOF - - - - - - -EOF - - pgac_cmd='$ANT -buildfile conftest.xml 1>&2' - { (eval echo "$as_me:$LINENO: \"$pgac_cmd\"") >&5 - (eval $pgac_cmd) 2>&5 - ac_status=$? - echo "$as_me:$LINENO: \$? = $ac_status" >&5 - (exit $ac_status); } - pgac_save_status=$? - if test $? = 0 && test -f ./conftest.class ; then - pgac_cv_prog_ant_works=yes - else - echo "configure: failed java program was:" >&5 - cat conftest.java >&5 - echo "configure: failed build file was:" >&5 - cat conftest.xml >&5 - pgac_cv_prog_ant_works=no - fi - - rm -f conftest* core core.* *.core - -fi -echo "$as_me:$LINENO: result: $pgac_cv_prog_ant_works" >&5 -echo "${ECHO_T}$pgac_cv_prog_ant_works" >&6 - - if test "$pgac_cv_prog_ant_works" != yes; then - { { echo "$as_me:$LINENO: error: ant does not work" >&5 -echo "$as_me: error: ant does not work" >&2;} - { (exit 1); exit 1; }; } - fi - - -if test -z "$ANT"; then - { { echo "$as_me:$LINENO: error: Ant is required to build Java components -If you have Ant already installed, see config.log for details on the failure." >&5 -echo "$as_me: error: Ant is required to build Java components -If you have Ant already installed, see config.log for details on the failure." >&2;} - { (exit 1); exit 1; }; } -fi -if "$ANT" -version | egrep -i 'ant version' | sed q | egrep -v ' 1\.[5-9]| [2-9]\.' >/dev/null ; then - { { echo "$as_me:$LINENO: error: Ant version >= 1.5 is required to build Java components" >&5 -echo "$as_me: error: Ant version >= 1.5 is required to build Java components" >&2;} - { (exit 1); exit 1; }; } -fi - ;; - no) - echo "$as_me:$LINENO: result: no" >&5 -echo "${ECHO_T}no" >&6 - ;; - *) - { { echo "$as_me:$LINENO: error: no argument expected for --with-java option" >&5 -echo "$as_me: error: no argument expected for --with-java option" >&2;} - { (exit 1); exit 1; }; } - ;; - esac - -else - with_java=no -echo "$as_me:$LINENO: result: no" >&5 -echo "${ECHO_T}no" >&6 -fi; - - - # # Kerberos 4 # @@ -18252,8 +18104,6 @@ s,@with_tcl@,$with_tcl,;t t s,@with_tk@,$with_tk,;t t s,@with_perl@,$with_perl,;t t s,@with_python@,$with_python,;t t -s,@ANT@,$ANT,;t t -s,@with_java@,$with_java,;t t s,@with_krb4@,$with_krb4,;t t s,@with_krb5@,$with_krb5,;t t s,@krb_srvtab@,$krb_srvtab,;t t diff --git a/configure.in b/configure.in index 1ed6c78d22..29dd95cac7 100644 --- a/configure.in +++ b/configure.in @@ -1,5 +1,5 @@ dnl Process this file with autoconf to produce a configure script. -dnl $PostgreSQL: pgsql/configure.in,v 1.310 2004/01/09 04:58:09 momjian Exp $ +dnl $PostgreSQL: pgsql/configure.in,v 1.311 2004/01/19 21:20:05 tgl Exp $ dnl dnl Developers, please strive to achieve this order: dnl @@ -409,23 +409,6 @@ PGAC_ARG_BOOL(with, python, no, [ --with-python build Python modules AC_MSG_RESULT([$with_python]) AC_SUBST(with_python) -# -# Optionally build the Java/JDBC tools -# -AC_MSG_CHECKING([whether to build Java/JDBC tools]) -PGAC_ARG_BOOL(with, java, no, [ --with-java build JDBC interface and Java tools], -[AC_MSG_RESULT(yes) -PGAC_PATH_ANT -if test -z "$ANT"; then - AC_MSG_ERROR([Ant is required to build Java components -If you have Ant already installed, see config.log for details on the failure.]) -fi -if "$ANT" -version | egrep -i 'ant version' | sed q | egrep -v ' 1\.[[5-9]]| [[2-9]]\.' >/dev/null ; then - AC_MSG_ERROR([Ant version >= 1.5 is required to build Java components]) -fi], -[AC_MSG_RESULT(no)]) -AC_SUBST(with_java) - # # Kerberos 4 # diff --git a/doc/src/sgml/filelist.sgml b/doc/src/sgml/filelist.sgml index bbfd55d9b4..3fd9ce9045 100644 --- a/doc/src/sgml/filelist.sgml +++ b/doc/src/sgml/filelist.sgml @@ -1,4 +1,4 @@ - + @@ -49,7 +49,6 @@ - diff --git a/doc/src/sgml/installation.sgml b/doc/src/sgml/installation.sgml index 1fc151abeb..368d82e3cb 100644 --- a/doc/src/sgml/installation.sgml +++ b/doc/src/sgml/installation.sgml @@ -1,4 +1,4 @@ - + <![%standalone-include[<productname>PostgreSQL</>]]> @@ -212,41 +212,6 @@ su - postgres </para> </listitem> - <listitem> - <para> - To build the JDBC driver, you need - <application>Ant</application> 1.5 or higher and a - <acronym>JDK</acronym>. <application>Ant</application> is a - special tool for building Java-based packages. It can be - downloaded from the <ulink - url="http://jakarta.apache.org/ant/index.html"><application>Ant</application> - web site</ulink>. - </para> - - <para> - If you have several Java compilers installed, it depends on the - Ant configuration which one gets used. Precompiled - <application>Ant</application> distributions are typically set - up to read a file <filename>.antrc</filename> in the current - user's home directory for configuration. For example, to use a - different <acronym>JDK</acronym> than the default, this may - work: -<programlisting> -JAVA_HOME=/usr/local/sun-jdk1.3 -JAVACMD=$JAVA_HOME/bin/java -</programlisting> - </para> - - <note> - <para> - Do not try to build the driver by calling - <command>ant</command> or even <command>javac</command> - directly. This will not work. Run <command>gmake</command> - normally as described below. - </para> - </note> - </listitem> - <listitem> <para> To enable Native Language Support (<acronym>NLS</acronym>), that @@ -801,16 +766,6 @@ JAVACMD=$JAVA_HOME/bin/java </listitem> </varlistentry> - <varlistentry> - <term><option>--with-java</option></term> - <listitem> - <para> - Build the <acronym>JDBC</acronym> driver and associated Java - packages. - </para> - </listitem> - </varlistentry> - <varlistentry> <term><option>--with-krb4</option></term> <term><option>--with-krb5</option></term> diff --git a/doc/src/sgml/jdbc.sgml b/doc/src/sgml/jdbc.sgml deleted file mode 100644 index e2f0f39347..0000000000 --- a/doc/src/sgml/jdbc.sgml +++ /dev/null @@ -1,3197 +0,0 @@ -<!-- -$PostgreSQL: pgsql/doc/src/sgml/jdbc.sgml,v 1.52 2003/12/13 23:59:06 neilc Exp $ ---> - - <chapter id="jdbc"> - <title><acronym>JDBC</acronym> Interface - - - JDBC - - - - Java - - - - JDBC is a core API of Java 1.1 and later. - It provides a standard set of - interfaces to SQL-compliant databases. - - - - PostgreSQL provides a type - 4 JDBC driver. Type 4 indicates - that the driver is written in Pure Java, and communicates in the - database system's own network protocol. Because of this, the driver - is platform independent; once compiled, the driver can be used on - any system. - - - - This chapter is not intended as a complete guide to - JDBC programming, but should help to get you - started. For more information refer to the standard - JDBC API documentation. - Also, take a look at the examples included with the source. - - - - Setting up the <acronym>JDBC</acronym> Driver - - - This section describes the steps you need to take before you can - write or run programs that use the JDBC interface. - - - - Getting the Driver - - - Precompiled versions of the driver can be downloaded from - the PostgreSQL - JDBC web site. - - - - Alternatively you can build the driver from source, but you should - only need to do this if you are making changes to the source code. - For details, refer to the PostgreSQL - installation instructions. - After installation, the driver should be found in - PREFIX/share/java/postgresql.jar. - The resulting driver will be built for the version of Java you are - running. If you build with a 1.1 JDK you will build a - version that supports the JDBC 1 specification, if you build - with a 1.2 or 1.3 JDK you will build a version that supports - the JDBC 2 specification, and finally if you build with a - 1.4 JDK you will build a version that supports the - JDBC 3 specification. - - - - - Setting up the Class Path - - - class path - - - - CLASSPATH - - - - To use the driver, the JAR archive (named - postgresql.jar if you built from source, otherwise - it will likely be named pg&majorversion;jdbc1.jar, - pg&majorversion;jdbc2.jar, or - pg&majorversion;jdbc3.jar for the JDBC 1, - JDBC 2, and JDBC 3 versions respectively) - needs to be included in the class path, either by putting it in the - CLASSPATH environment variable, or by using flags on the - java command line. - - - - For instance, assume we have an application that uses the - JDBC driver to access a database, and that - application is installed as - /usr/local/lib/myapp.jar. The - PostgreSQL JDBC driver installed as - /usr/local/pgsql/share/java/postgresql.jar. To run - the application, we would use: - -export CLASSPATH=/usr/local/lib/myapp.jar:/usr/local/pgsql/share/java/postgresql.jar:. -java MyApp - - - - - Loading the driver from within the application is covered in - . - - - - - Preparing the Database Server for <acronym>JDBC</acronym> - - - Because Java only uses TCP/IP connections, the - PostgreSQL server must be configured to - accept TCP/IP connections. This can be done by setting - tcpip_socket = true in the - postgresql.conf file or by supplying the - option flag when starting - postmaster. - - - - Also, the client authentication setup in the - pg_hba.conf file may need to be configured. - Refer to for details. The - JDBC driver supports the trust, - ident, password, md5, and - crypt authentication methods. - - - - - - Initializing the Driver - - - This section describes how to load and initialize the JDBC - driver in your programs. - - - - Importing <acronym>JDBC</acronym> - - - Any source that uses JDBC needs to import the - java.sql package, using: - - -import java.sql.*; - - - - - - Do not import the org.postgresql package. If - you do, your source will not compile, as - javac will get confused. - - - - - - Loading the Driver - - - Before you can connect to a database, you need to load the - driver. There are two methods available, and it depends on your - code which is the best one to use. - - - - In the first method, your code implicitly loads the driver using the - Class.forName() method. - For PostgreSQL, you would use: - - -Class.forName("org.postgresql.Driver"); - - - This will load the driver, and while loading, the driver will automatically - register itself with JDBC. - - - - - The forName() method can throw a - ClassNotFoundException if the driver is - not available. - - - - - This is the most common method to use, but restricts your code to - use just PostgreSQL. If your code may - access another database system in the future, and you do not use - any PostgreSQL-specific extensions, then - the second method is advisable. - - - - The second method passes the driver as a parameter to the - JVM as it starts, using the - argument. Example: - -java -Djdbc.drivers=org.postgresql.Driver example.ImageViewer - - In this example, the JVM will attempt to load - the driver as part of its initialization. Once done, the - ImageViewer is started. - - - - Now, this method is the better one to use because it allows your - code to be used with other database packages without recompiling - the code. The only thing that would also change is the connection - URL, which is covered next. - - - - One last thing: When your code then tries to open a - Connection, and you get a No - driver available SQLException - being thrown, this is probably caused by the driver not being in - the class path, or the value in the parameter not being correct. - - - - - Connecting to the Database - - - With JDBC, a database is represented by a - URL (Uniform Resource Locator). With - PostgreSQL, this takes one of the - following forms: - - - - -jdbc:postgresql:database - - - - - -jdbc:postgresql://host/database - - - - - -jdbc:postgresql://host:port/database - - - - - The parameters have the following meanings: - - - - - host - - - - The host name of the server. Defaults to localhost. To specify an IPv6 address your must enclose the host parameter with square brackets, for example: - -jdbc:postgresql://[::1]:5740/accounting - - - - - - - - port - - - - The port number the server is listening on. Defaults to the - PostgreSQL standard port number (5432). - - - - - - - database - - - - The database name. - - - - - - - - To connect, you need to get a Connection instance from - JDBC. To do this, - you use the DriverManager.getConnection() method: - - -Connection db = DriverManager.getConnection(url, username, password); - - - - - - Closing the Connection - - - To close the database connection, simply call the - close() method to the Connection: - -db.close(); - - - - - - - - Issuing a Query and Processing the Result - - - Statement - - - - PreparedStatement - - - - ResultSet - - - - Any time you want to issue SQL statements to - the database, you require a Statement or - PreparedStatement instance. Once you have - a Statement or - PreparedStatement, you can use issue a - query. This will return a ResultSet - instance, which contains the entire result (see - here for how to alter this behaviour). - illustrates this process. - - - - Processing a Simple Query in <acronym>JDBC</acronym> - - - This example will issue a simple query and print out the first - column of each row using a Statement. - -Statement st = db.createStatement(); -ResultSet rs = st.executeQuery("SELECT * FROM mytable WHERE columnfoo = 500"); -while (rs.next()) { - System.out.print("Column 1 returned "); - System.out.println(rs.getString(1)); -} -rs.close(); -st.close(); - - - - - This example issues the same query as before but uses - a PreparedStatement - and a bind value in the query. - -int foovalue = 500; -PreparedStatement st = db.prepareStatement("SELECT * FROM mytable WHERE columnfoo = ?"); -st.setInt(1, foovalue); -ResultSet rs = st.executeQuery(); -while (rs.next()) { - System.out.print("Column 1 returned "); - System.out.println(rs.getString(1)); -} -rs.close(); -st.close(); - - - - - - Getting results based on a cursor - - By default the driver collects all the results for the - query at once. This can be inconvenient for large data sets so - the JDBC driver provides a means of basing - a ResultSet on a database cursor and - only fetching a small number of rows. - - A small number of rows are cached on the - client side of the connection and when exhausted the next - block of rows is retrieved by repositioning the cursor. - - - - Setting fetch size to turn cursors on and off. - - Changing code to cursor mode is as simple as setting the - fetch size of the Statement to the - appropriate size. Setting the fetch size back to 0 will cause - all rows to be cached (the default behaviour). - - -Statement st = db.createStatement(); -// Turn use of the cursor on. -st.setFetchSize(50); -ResultSet rs = st.executeQuery("SELECT * FROM mytable"); -while (rs.next()) { - System.out.print("a row was returned."); -} -rs.close(); -// Turn the cursor off. -st.setFetchSize(0); -ResultSet rs = st.executeQuery("SELECT * FROM mytable"); -while (rs.next()) { - System.out.print("many rows were returned."); -} -rs.close(); -// Close the statement. -st.close(); - - - - - - - Using the <classname>Statement</classname> or <classname>PreparedStatement</classname> Interface - - - The following must be considered when using the - Statement or - PreparedStatement interface: - - - - - You can use a single Statement instance - as many times as you want. You could create one as soon as you - open the connection and use it for the connection's - lifetime. But you have to remember that only one - ResultSet can exist per - Statement or - PreparedStatement at a given time. - - - - - - If you need to perform a query while processing a - ResultSet, you can simply create and - use another Statement. - - - - - - If you are using threads, and several are using the database, - you must use a separate Statement for - each thread. Refer to if you are - thinking of using threads, as it covers some important points. - - - - - - When you are done using the Statement - or PreparedStatement - you should close it. - - - - - - - - Using the <classname>ResultSet</classname> Interface - - - The following must be considered when using the - ResultSet interface: - - - - - Before reading any values, you must call - next(). This returns true if there is a - result, but more importantly, it prepares the row for - processing. - - - - - - Under the JDBC specification, you should - access a field only once. It is safest to stick to this rule, - although at the current time, the - PostgreSQL driver will allow you to - access a field as many times as you want. - - - - - - You must close a ResultSet by calling - close() once you have finished using it. - - - - - - Once you make another query with the - Statement used to create a - ResultSet, the currently open - ResultSet instance is closed - automatically. - - - - - - - - - - Performing Updates - - - To change data (perform an INSERT, - UPDATE, or DELETE) you use - the executeUpdate() method. This method is - similar to the method executeQuery() used to - issue a SELECT statement, but it doesn't return - a ResultSet; instead it returns the number - of rows affected by the INSERT, - UPDATE, or DELETE statement. - illustrates the usage. - - - - Deleting Rows in <acronym>JDBC</acronym> - - This example will issue a simple DELETE - statement and print out the number of rows deleted. - -int foovalue = 500; -PreparedStatement st = db.prepareStatement("DELETE FROM mytable WHERE columnfoo = ?"); -st.setInt(1, foovalue); -int rowsDeleted = st.executeUpdate(); -System.out.println(rowsDeleted + " rows deleted"); -st.close(); - - - - - - - - Calling Stored Functions - - PostgreSQL's JDBC driver fully - supports calling PostgreSQL stored - functions. - - - Calling a built in stored function - - This example shows how to call - a PostgreSQL built in - function, upper, which simply converts the - supplied string argument to uppercase. - - -// Turn transactions off. -con.setAutoCommit(false); -// Procedure call. -CallableStatement upperProc = con.prepareCall("{ ? = call upper( ? ) }"); -upperProc.registerOutParameter(1, Types.VARCHAR); -upperProc.setString(2, "lowercase to uppercase"); -upperProc.execute(); -String upperCased = upperProc.getString(1); -upperProc.close(); - - - - - - Using the <classname>CallableStatement</classname> Interface - - - All the considerations that apply - for Statement - and PreparedStatement apply - for CallableStatement but in addition - you must also consider one extra restriction: - - - - - You can only call a stored function from within a - transaction. - - - - - - - Obtaining <classname>ResultSet</classname> from a stored function - - PostgreSQL's stored function - can return results by means of a refcursor - value. A refcursor. - - As an extension to JDBC, - the PostgreSQL JDBC driver can - return refcursor values - as ResultSet values. - - - Getting <type>refcursor</type> values from a - function - - When calling a function that returns - a refcursor you must cast the return type - of getObject to - a ResultSet - - -// Turn transactions off. -con.setAutoCommit(false); -// Procedure call. -CallableStatement proc = con.prepareCall("{ ? = call doquery ( ? ) }"); -proc.registerOutParameter(1, Types.Other); -proc.setInt(2, -1); -proc.execute(); -ResultSet results = (ResultSet) proc.getObject(1); -while (results.next()) { - // do something with the results... -} -results.close(); -proc.close(); - - - - It is also possible to treat the refcursor - return value as a distinct type in itself. The JDBC driver - provides - the org.postgresql.PGRefCursorResultSet - class for this purpose. - - - Treating <type>refcursor</type> as a distinct - type - - -con.setAutoCommit(false); -CallableStatement proc = con.prepareCall("{ ? = call doquery ( ? ) }"); -proc.registerOutParameter(1, Types.Other); -proc.setInt(2, 0); -org.postgresql.PGRefCursorResultSet refcurs - = (PGRefCursorResultSet) con.getObject(1); -String cursorName = refcurs.getRefCursor(); -proc.close(); - - - - - - - - - Creating and Modifying Database Objects - - - To create, modify or drop a database object like a table or view - you use the execute() method. This method is - similar to the method executeQuery(), but it - doesn't return a result. - illustrates the usage. - - - - Dropping a Table in JDBC - - This example will drop a table. - -Statement st = db.createStatement(); -st.execute("DROP TABLE mytable"); -st.close(); - - - - - - - Storing Binary Data - - - bytea - in JDBC - - - - large object - in JDBC - - - - PostgreSQL provides two distinct ways to - store binary data. Binary data can be stored in a table using - the data type bytea or by using the Large Object - feature which stores the binary data in a separate table in a special - format and refers to that table by storing a value of type - oid in your table. - - - - In order to determine which method is appropriate you - need to understand the limitations of each method. The - bytea data type is not well suited for storing very - large amounts of binary data. While a column of type - bytea can hold up to 1 GB of binary data, it would - require a huge amount of memory to - process such a large value. The Large Object method for - storing binary data is better suited to storing very large values, - but it has its own limitations. Specifically deleting a row - that contains a Large Object reference does not delete the Large Object. - Deleting the Large Object is a separate operation that needs to - be performed. Large Objects also have some security - issues since anyone connected to the database can view - and/or modify any Large Object, even if they don't have - permissions to view/update the row containing the Large Object reference. - - - - Version 7.2 was the first release of the JDBC driver - that supports the bytea data type. The introduction of - this functionality in 7.2 has introduced a change in behavior - as compared to previous releases. Since 7.2, the methods - getBytes(), setBytes(), - getBinaryStream(), and - setBinaryStream() operate on - the bytea data type. In 7.1 and earlier, these methods operated - on the oid data type associated with Large Objects. - It is possible to revert the driver back to the old 7.1 behavior - by setting the property compatible on - the Connection object to the value - 7.1. - - - - To use the bytea data type you should simply use - the getBytes(), setBytes(), - getBinaryStream(), or - setBinaryStream() methods. - - - - To use the Large Object functionality you can use either the - LargeObject class provided by the - PostgreSQL JDBC driver, or by - using the getBLOB() and - setBLOB() methods. - - - - - You must access Large Objects within an SQL - transaction block. You can start a transaction block by calling - setAutoCommit(false). - - - - - - In a future release of the - JDBC driver, the getBLOB() - and setBLOB() methods may no longer - interact with Large Objects and will instead work on the data type - bytea. So it is recommended that you - use the LargeObject API - if you intend to use Large Objects. - - - - - contains some examples on - how to process binary data using the PostgreSQL - JDBC driver. - - - - Processing Binary Data in <acronym>JDBC</> - - - For example, suppose you have a table containing the file names of - images and you also want to store the image in a bytea - column: - -CREATE TABLE images (imgname text, img bytea); - - - - - To insert an image, you would use: - -File file = new File("myimage.gif"); -FileInputStream fis = new FileInputStream(file); -PreparedStatement ps = conn.prepareStatement("INSERT INTO images VALUES (?, ?)"); -ps.setString(1, file.getName()); -ps.setBinaryStream(2, fis, file.length()); -ps.executeUpdate(); -ps.close(); -fis.close(); - - - Here, setBinaryStream() transfers a set number - of bytes from a stream into the column of type bytea. - This also could have been done using the setBytes() - method if the contents of the image was already in a - byte[]. - - - - Retrieving an image is even easier. (We use - PreparedStatement here, but the - Statement class can equally be used.) - - -PreparedStatement ps = con.prepareStatement("SELECT img FROM images WHERE imgname = ?"); -ps.setString(1, "myimage.gif"); -ResultSet rs = ps.executeQuery(); -if (rs != null) { - while (rs.next()) { - byte[] imgBytes = rs.getBytes(1); - // use the data in some way here - } - rs.close(); -} -ps.close(); - - - - - Here the binary data was retrieved as an - byte[]. You could have used a - InputStream object instead. - - - - Alternatively you could be storing a very large file and want to use - the LargeObject API to - store the file: - -CREATE TABLE imageslo (imgname text, imgoid oid); - - - - - To insert an image, you would use: - -// All LargeObject API calls must be within a transaction block -conn.setAutoCommit(false); - -// Get the Large Object Manager to perform operations with -LargeObjectManager lobj = ((org.postgresql.PGConnection)conn).getLargeObjectAPI(); - -// Create a new large object -int oid = lobj.create(LargeObjectManager.READ | LargeObjectManager.WRITE); - -// Open the large object for writing -LargeObject obj = lobj.open(oid, LargeObjectManager.WRITE); - -// Now open the file -File file = new File("myimage.gif"); -FileInputStream fis = new FileInputStream(file); - -// Copy the data from the file to the large object -byte buf[] = new byte[2048]; -int s, tl = 0; -while ((s = fis.read(buf, 0, 2048)) > 0) { - obj.write(buf, 0, s); - tl += s; -} - -// Close the large object -obj.close(); - -// Now insert the row into imageslo -PreparedStatement ps = conn.prepareStatement("INSERT INTO imageslo VALUES (?, ?)"); -ps.setString(1, file.getName()); -ps.setInt(2, oid); -ps.executeUpdate(); -ps.close(); -fis.close(); - - - - - Retrieving the image from the Large Object: - - -// All LargeObject API calls must be within a transaction block -conn.setAutoCommit(false); - -// Get the Large Object Manager to perform operations with -LargeObjectManager lobj = ((org.postgresql.PGConnection)conn).getLargeObjectAPI(); - -PreparedStatement ps = con.prepareStatement("SELECT imgoid FROM imageslo WHERE imgname = ?"); -ps.setString(1, "myimage.gif"); -ResultSet rs = ps.executeQuery(); -if (rs != null) { - while (rs.next()) { - // Open the large object for reading - int oid = rs.getInt(1); - LargeObject obj = lobj.open(oid, LargeObjectManager.READ); - - // Read the data - byte buf[] = new byte[obj.size()]; - obj.read(buf, 0, obj.size()); - // Do something with the data read here - - // Close the object - obj.close(); - } - rs.close(); -} -ps.close(); - - - - - - - - - <productname>PostgreSQL</productname> Extensions to the - <acronym>JDBC</acronym> <acronym>API</acronym> - - - PostgreSQL is an extensible database - system. You can add your own functions to the server, which can - then be called from queries, or even add your own data types. As - these are facilities unique to PostgreSQL, - we support them from Java, with a set of extension - API's. Some features within the core of the - standard driver actually use these extensions to implement Large - Objects, etc. - - - - Accessing the Extensions - - - To access some of the extensions, you need to use some extra - methods in the org.postgresql.PGConnection - class. In this case, you would need to case the return value of - Driver.getConnection(). For example: - -Connection db = Driver.getConnection(url, username, password); -// ... -// later on -Fastpath fp = ((org.postgresql.PGConnection)db).getFastpathAPI(); - - - - - Class <classname>org.postgresql.PGConnection</classname> - - -public class PGConnection - - - - These are the extra methods used to gain access to - PostgreSQL's extensions. - - - - Methods - - - - -public Fastpath getFastpathAPI() throws SQLException - - - This returns the fast-path API for the - current connection. It is primarily used by the Large Object - API. - - - - The best way to use this is as follows: - -import org.postgresql.fastpath.*; -... -Fastpath fp = ((org.postgresql.PGConnection)myconn).getFastpathAPI(); - - where myconn is an open Connection to PostgreSQL. - - - - Returns: - - Fastpath object allowing access to functions on the - PostgreSQL server. - - - - - Throws: - - SQLException by Fastpath when initializing for first time - - - - - - - -public LargeObjectManager getLargeObjectAPI() throws SQLException - - This returns the Large Object API for the - current connection. - - - - The best way to use this is as follows: - -import org.postgresql.largeobject.*; -... -LargeObjectManager lo = ((org.postgresql.PGConnection)myconn).getLargeObjectAPI(); - - where myconn is an open Connection to - PostgreSQL. - - - - Returns: - - LargeObject object that implements the API - - - - - Throws: - - SQLException by LargeObject when initializing for first time - - - - - - - -public void addDataType(String type, String name) - - This allows client code to add a handler for one of - PostgreSQL's more unique data types. Normally, a data type not - known by the driver is returned by ResultSet.getObject() as a - PGobject instance. This method allows you to write a class - that extends PGobject, and tell the driver the type name, and - class name to use. The down side to this, is that you must - call this method each time a connection is made. - - - - The best way to use this is as follows: - - ... -((org.postgresql.PGConnection)myconn).addDataType("mytype","my.class.name"); - ... - - where myconn is an open Connection to - PostgreSQL. The handling class must - extend org.postgresql.util.PGobject. - - - - - - - - - Class <classname>org.postgresql.Fastpath</classname> - - -public class Fastpath extends Object - -java.lang.Object - | - +----org.postgresql.fastpath.Fastpath - - - - Fastpath is an API that - exists within the libpq C interface, and allows a client machine - to execute a function on the database server. Most client code - will not need to use this method, but it is provided because the - Large Object API uses it. - - - - To use, you need to import the - org.postgresql.fastpath package, using the - line: - -import org.postgresql.fastpath.*; - - Then, in your code, you need to get a - FastPath object: - -Fastpath fp = ((org.postgresql.PGConnection)conn).getFastpathAPI(); - - This will return an instance associated with the database - connection that you can use to issue commands. The casing of - Connection to - org.postgresql.PGConnection is required, as - the getFastpathAPI() is an extension method, - not part of JDBC. Once you have a - Fastpath instance, you can use the - fastpath() methods to execute a server - function. - - - - See Also: - - FastpathFastpathArg, LargeObject - - - - - Methods - - - - -public Object fastpath(int fnid, - boolean resulttype, - FastpathArg args[]) throws SQLException - - - Send a function call to the PostgreSQL server. - - - - Parameters: - - fnid - Function id - resulttype - True if the result is an integer, false -for - other results - args - FastpathArguments to pass to fast-path call - - - - - Returns: - - null if no data, Integer if an integer result, or byte[] - otherwise - - - - - - -public Object fastpath(String name, - boolean resulttype, - FastpathArg args[]) throws SQLException - - - Send a function call to the PostgreSQL server by name. - - - - - The mapping for the procedure name to function id needs to - exist, usually to an earlier call to addfunction(). This is - the preferred method to call, as function id's can/may change - between versions of the server. For an example of how this - works, refer to org.postgresql.LargeObject - - - - - Parameters: - - name - Function name - resulttype - True if the result is an integer, false -for - other results - args - FastpathArguments to pass to fast-path call - - - - - Returns: - - null if no data, Integer if an integer result, or byte[] - otherwise - - - - - See Also: - LargeObject - - - - - -public int getInteger(String name, - FastpathArg args[]) throws SQLException - - - This convenience method assumes that the return value is an Integer - - - - Parameters: - - name - Function name - args - Function arguments - - - - - Returns: - integer result - - - - Throws: - - SQLException if a database-access error occurs or no result - - - - - - -public byte[] getData(String name, - FastpathArg args[]) throws SQLException - - - This convenience method assumes that the return value is binary - data. - - - - Parameters: - - name - Function name - args - Function arguments - - - - - Returns: - byte[] array containing result - - - - Throws: - - SQLException if a database-access error occurs or no result - - - - - - -public void addFunction(String name, - int fnid) - - - This adds a function to our look-up table. User code should - use the addFunctions method, which is based upon a query, - rather than hard coding the OID. The OID for a function is not - guaranteed to remain static, even on different servers of the - same version. - - - - - -public void addFunctions(ResultSet rs) throws SQLException - - - This takes a ResultSet containing two columns. Column 1 - contains the function name, Column 2 the OID. It reads the - entire ResultSet, loading the values into the function table. - - - - - Remember to close() the - ResultSet after calling this! - - - - - Implementation note about function name look-ups - - - PostgreSQL stores the function id's and their corresponding - names in the pg_proc table. To speed things up locally, - instead of querying each function from that table when - required, a Hashtable is used. Also, only the function's - required are entered into this table, keeping connection - times as fast as possible. - - - - The org.postgresql.LargeObject class - performs a query upon its start-up, and passes the returned - ResultSet to the - addFunctions() method here. Once this - has been done, the Large Object API refers - to the functions by name. - - - - Do not think that manually converting them to the OIDs will - work. OK, they will for now, but they can change during - development (there was some discussion about this for V7.0), - so this is implemented to prevent any unwarranted headaches - in the future. - - - - - See Also: - - LargeObjectManager - - - - - - -public int getID(String name) throws SQLException - - - This returns the function id associated by its name If - addFunction() or addFunctions() have not been called for this - name, then an SQLException is thrown. - - - - - - - - - Class <classname>org.postgresql.fastpath.FastpathArg</classname> - - -public class FastpathArg extends Object - -java.lang.Object - | - +----org.postgresql.fastpath.FastpathArg - - - - Each fast-path call requires an array of arguments, the number and - type dependent on the function being called. This class - implements methods needed to provide this capability. - - - - For an example on how to use this, refer to the - org.postgresql.LargeObject package. - - - - See Also: - - Fastpath, LargeObjectManager, LargeObject - - - - - Constructors - - - - -public FastpathArg(int value) - - - Constructs an argument that consists of an integer value - - - - Parameters: - - value - int value to set - - - - - - -public FastpathArg(byte bytes[]) - - - Constructs an argument that consists of an array of bytes - - - - Parameters: - - bytes - array to store - - - - - - -public FastpathArg(byte buf[], - int off, - int len) - - - Constructs an argument that consists of part of a byte array - - - - Parameters: - - - - buf - - source array - - - - - off - - offset within array - - - - - len - - length of data to include - - - - - - - - - -public FastpathArg(String s) - - - Constructs an argument that consists of a String. - - - - - - - - - - Geometric Data Types - - - PostgreSQL has a set of data types that - can store geometric features into a table. These include single - points, lines, and polygons. We support these types in Java with - the org.postgresql.geometric package. It contains classes that - extend the org.postgresql.util.PGobject class. Refer to that - class for details on how to implement your own data type handlers. - - - -Class org.postgresql.geometric.PGbox - -java.lang.Object - | - +----org.postgresql.util.PGobject - | - +----org.postgresql.geometric.PGbox - - public class PGbox extends PGobject implements Serializable, -Cloneable - - This represents the box data type within PostgreSQL. - -Variables - - public PGpoint point[] - - These are the two corner points of the box. - -Constructors - - public PGbox(double x1, - double y1, - double x2, - double y2) - - Parameters: - x1 - first x coordinate - y1 - first y coordinate - x2 - second x coordinate - y2 - second y coordinate - - public PGbox(PGpoint p1, - PGpoint p2) - - Parameters: - p1 - first point - p2 - second point - - public PGbox(String s) throws SQLException - - Parameters: - s - Box definition in PostgreSQL syntax - - Throws: SQLException - if definition is invalid - - public PGbox() - - Required constructor - -Methods - - public void setValue(String value) throws SQLException - - This method sets the value of this object. It should be -overridden, but still called by subclasses. - - Parameters: - value - a string representation of the value of the -object - Throws: SQLException - thrown if value is invalid for this type - - Overrides: - setValue in class PGobject - - public boolean equals(Object obj) - - Parameters: - obj - Object to compare with - - Returns: - true if the two boxes are identical - - Overrides: - equals in class PGobject - - public Object clone() - - This must be overridden to allow the object to be cloned - - Overrides: - clone in class PGobject - - public String getValue() - - Returns: - the PGbox in the syntax expected by PostgreSQL - - Overrides: - getValue in class PGobject - - -Class org.postgresql.geometric.PGcircle - -java.lang.Object - | - +----org.postgresql.util.PGobject - | - +----org.postgresql.geometric.PGcircle - - public class PGcircle extends PGobject implements Serializable, -Cloneable - - This represents PostgreSQL's circle data type, consisting of a point -and a radius - -Variables - - public PGpoint center - - This is the center point - - double radius - - This is the radius - -Constructors - - public PGcircle(double x, - double y, - double r) - - Parameters: - x - coordinate of center - y - coordinate of center - r - radius of circle - - public PGcircle(PGpoint c, - double r) - - Parameters: - c - PGpoint describing the circle's center - r - radius of circle - - public PGcircle(String s) throws SQLException - - Parameters: - s - definition of the circle in PostgreSQL's syntax. - - Throws: SQLException - on conversion failure - - public PGcircle() - - This constructor is used by the driver. - -Methods - - public void setValue(String s) throws SQLException - - Parameters: - s - definition of the circle in PostgreSQL's syntax. - - Throws: SQLException - on conversion failure - - Overrides: - setValue in class PGobject - - public boolean equals(Object obj) - - Parameters: - obj - Object to compare with - - Returns: - true if the two circles are identical - - Overrides: - equals in class PGobject - - public Object clone() - - This must be overridden to allow the object to be cloned - - Overrides: - clone in class PGobject - - public String getValue() - - Returns: - the PGcircle in the syntax expected by PostgreSQL - - Overrides: - getValue in class PGobject - - -Class org.postgresql.geometric.PGline - -java.lang.Object - | - +----org.postgresql.util.PGobject - | - +----org.postgresql.geometric.PGline - - public class PGline extends PGobject implements Serializable, -Cloneable - - This implements a line consisting of two points. Currently line is -not yet implemented in the server, but this class ensures that when -it's done were ready for it. - -Variables - - public PGpoint point[] - - These are the two points. - -Constructors - - public PGline(double x1, - double y1, - double x2, - double y2) - - Parameters: - x1 - coordinate for first point - y1 - coordinate for first point - x2 - coordinate for second point - y2 - coordinate for second point - - public PGline(PGpoint p1, - PGpoint p2) - - Parameters: - p1 - first point - p2 - second point - - public PGline(String s) throws SQLException - - Parameters: - s - definition of the line in PostgreSQL's syntax. - - Throws: SQLException - on conversion failure - - public PGline() - - required by the driver - -Methods - - public void setValue(String s) throws SQLException - - Parameters: - s - Definition of the line segment in PostgreSQL's -syntax - - Throws: SQLException - on conversion failure - - Overrides: - setValue in class PGobject - - public boolean equals(Object obj) - - Parameters: - obj - Object to compare with - - Returns: - true if the two lines are identical - - Overrides: - equals in class PGobject - - public Object clone() - - This must be overridden to allow the object to be cloned - - Overrides: - clone in class PGobject - - public String getValue() - - Returns: - the PGline in the syntax expected by PostgreSQL - - Overrides: - getValue in class PGobject - - -Class org.postgresql.geometric.PGlseg - -java.lang.Object - | - +----org.postgresql.util.PGobject - | - +----org.postgresql.geometric.PGlseg - - public class PGlseg extends PGobject implements Serializable, -Cloneable - - This implements a lseg (line segment) consisting of two points - -Variables - - public PGpoint point[] - - These are the two points. - -Constructors - - public PGlseg(double x1, - double y1, - double x2, - double y2) - - Parameters: - - x1 - coordinate for first point - y1 - coordinate for first point - x2 - coordinate for second point - y2 - coordinate for second point - - public PGlseg(PGpoint p1, - PGpoint p2) - - Parameters: - p1 - first point - p2 - second point - - public PGlseg(String s) throws SQLException - - Parameters: - s - Definition of the line segment in PostgreSQL's syntax. - - Throws: SQLException - on conversion failure - - public PGlseg() - - required by the driver - -Methods - - public void setValue(String s) throws SQLException - - Parameters: - s - Definition of the line segment in PostgreSQL's -syntax - - Throws: SQLException - on conversion failure - - Overrides: - setValue in class PGobject - - public boolean equals(Object obj) - - Parameters: - obj - Object to compare with - - Returns: - true if the two line segments are identical - - Overrides: - equals in class PGobject - - public Object clone() - - This must be overridden to allow the object to be cloned - - Overrides: - clone in class PGobject - - public String getValue() - - Returns: - the PGlseg in the syntax expected by PostgreSQL - - Overrides: - getValue in class PGobject - - -Class org.postgresql.geometric.PGpath - -java.lang.Object - | - +----org.postgresql.util.PGobject - | - +----org.postgresql.geometric.PGpath - - public class PGpath extends PGobject implements Serializable, -Cloneable - - This implements a path (a multiply segmented line, which may be -closed) - -Variables - - public boolean open - - True if the path is open, false if closed - - public PGpoint points[] - - The points defining this path - -Constructors - - public PGpath(PGpoint points[], - boolean open) - - Parameters: - points - the PGpoints that define the path - open - True if the path is open, false if closed - - public PGpath() - - Required by the driver - - public PGpath(String s) throws SQLException - - Parameters: - s - definition of the path in PostgreSQL's syntax. - - Throws: SQLException - on conversion failure - -Methods - - public void setValue(String s) throws SQLException - - Parameters: - s - Definition of the path in PostgreSQL's syntax - - Throws: SQLException - on conversion failure - - Overrides: - setValue in class PGobject - - public boolean equals(Object obj) - - Parameters: - obj - Object to compare with - - Returns: - true if the two pathes are identical - - Overrides: - equals in class PGobject - - public Object clone() - - This must be overridden to allow the object to be cloned - - Overrides: - clone in class PGobject - - public String getValue() - - This returns the path in the syntax expected by -PostgreSQL - - Overrides: - getValue in class PGobject - - public boolean isOpen() - - This returns true if the path is open - - public boolean isClosed() - - This returns true if the path is closed - - public void closePath() - - Marks the path as closed - - public void openPath() - - Marks the path as open - - -Class org.postgresql.geometric.PGpoint - -java.lang.Object - | - +----org.postgresql.util.PGobject - | - +----org.postgresql.geometric.PGpoint - - public class PGpoint extends PGobject implements Serializable, -Cloneable - - This implements a version of java.awt.Point, except it uses double -to represent the coordinates. - - It maps to the point data type in PostgreSQL. - -Variables - - public double x - - The X coordinate of the point - - public double y - - The Y coordinate of the point - -Constructors - - public PGpoint(double x, - double y) - - Parameters: - x - coordinate - y - coordinate - - public PGpoint(String value) throws SQLException - - This is called mainly from the other geometric types, when a -point is embedded within their definition. - - Parameters: - value - Definition of this point in PostgreSQL's -syntax - - public PGpoint() - - Required by the driver - -Methods - - public void setValue(String s) throws SQLException - - Parameters: - s - Definition of this point in PostgreSQL's syntax - - Throws: SQLException - on conversion failure - - Overrides: - setValue in class PGobject - - public boolean equals(Object obj) - - Parameters: - obj - Object to compare with - - Returns: - true if the two points are identical - - Overrides: - equals in class PGobject - - public Object clone() - - This must be overridden to allow the object to be cloned - - Overrides: - clone in class PGobject - - public String getValue() - - Returns: - the PGpoint in the syntax expected by PostgreSQL - - Overrides: - getValue in class PGobject - - public void translate(int x, - int y) - - Translate the point with the supplied amount. - - Parameters: - x - integer amount to add on the x axis - y - integer amount to add on the y axis - - public void translate(double x, - double y) - - Translate the point with the supplied amount. - - Parameters: - x - double amount to add on the x axis - y - double amount to add on the y axis - - public void move(int x, - int y) - - Moves the point to the supplied coordinates. - - Parameters: - x - integer coordinate - y - integer coordinate - -public void move(double x, - double y) - - Moves the point to the supplied coordinates. - - Parameters: - x - double coordinate - y - double coordinate - - public void setLocation(int x, - int y) - - Moves the point to the supplied coordinates. refer to - java.awt.Point for description of this - - Parameters: - x - integer coordinate - y - integer coordinate - - See Also: - Point - - public void setLocation(Point p) - - Moves the point to the supplied java.awt.Point refer to - java.awt.Point for description of this - - Parameters: - p - Point to move to - - See Also: - Point - - -Class org.postgresql.geometric.PGpolygon - -java.lang.Object - | - +----org.postgresql.util.PGobject - | - +----org.postgresql.geometric.PGpolygon - - public class PGpolygon extends PGobject implements Serializable, -Cloneable - - This implements the polygon data type within PostgreSQL. - -Variables - - public PGpoint points[] - - The points defining the polygon - -Constructors - - public PGpolygon(PGpoint points[]) - - Creates a polygon using an array of PGpoints - - Parameters: - points - the points defining the polygon - - public PGpolygon(String s) throws SQLException - - Parameters: - s - definition of the polygon in PostgreSQL's syntax. - - Throws: SQLException - on conversion failure - - public PGpolygon() - - Required by the driver - -Methods - - public void setValue(String s) throws SQLException - - Parameters: - s - Definition of the polygon in PostgreSQL's syntax - - Throws: SQLException - on conversion failure - - Overrides: - setValue in class PGobject - - public boolean equals(Object obj) - - Parameters: - obj - Object to compare with - - Returns: - true if the two polygons are identical - - Overrides: - equals in class PGobject - - public Object clone() - - This must be overridden to allow the object to be cloned - - Overrides: - clone in class PGobject - - public String getValue() - - Returns: - the PGpolygon in the syntax expected by PostgreSQL - - Overrides: - getValue in class PGobject - - - - - - Large Objects - - - Large objects are supported in the standard - JDBC specification. However, that interface is - limited, and the API provided by PostgreSQL allows for random - access to the objects contents, as if it was a local file. - - - - The org.postgresql.largeobject package provides to Java the libpq - C interface's large object API. It consists of - two classes, LargeObjectManager, which deals with creating, - opening and deleting large objects, and LargeObject which deals - with an individual object. - - - - Class <classname>org.postgresql.largeobject.LargeObject</classname> - - -public class LargeObject extends Object - -java.lang.Object - | - +----org.postgresql.largeobject.LargeObject - - - - This class implements the large object interface to - PostgreSQL. - - - - It provides the basic methods required to run the interface, plus - a pair of methods that provide InputStream and OutputStream - classes for this object. - - - - Normally, client code would use the methods in - BLOB to access large objects. - - - - However, sometimes lower level access to Large Objects is - required, that is not supported by the JDBC - specification. - - - - Refer to org.postgresql.largeobject.LargeObjectManager on how to - gain access to a Large Object, or how to create one. - - - - See Also: - LargeObjectManager - - - - Variables - - - - public static final int SEEK_SET - - Indicates a seek from the beginning of a file - - - - - public static final int SEEK_CUR - - Indicates a seek from the current position - - - - - public static final int SEEK_END - - Indicates a seek from the end of a file - - - - - - - Methods - - - - -public int getOID() - - - Returns the OID of this LargeObject - - - - - -public void close() throws SQLException - - - This method closes the object. You must not call methods in - this object after this is called. - - - - - -public byte[] read(int len) throws SQLException - - - Reads some data from the object, and return as a byte[] array - - - - - -public int read(byte buf[], - int off, - int len) throws SQLException - - - Reads some data from the object into an existing array - - - - Parameters: - - - - buf - - destination array - - - - - off - - offset within array - - - - - len - - number of bytes to read - - - - - - - - - -public void write(byte buf[]) throws SQLException - - - Writes an array to the object - - - - - -public void write(byte buf[], - int off, - int len) throws SQLException - - - Writes some data from an array to the object - - - - Parameters: - - - - buf - - destination array - - - - - off - - offset within array - - - - - len - - number of bytes to write - - - - - - - - - - - - - - - Class <classname>org.postgresql.largeobject.LargeObjectManager</classname> - - -public class LargeObjectManager extends Object - -java.lang.Object - | - +----org.postgresql.largeobject.LargeObjectManager - - - - This class implements the large object interface to - PostgreSQL. It provides methods that - allow client code to create, open and delete large objects from - the database. When opening an object, an instance of - org.postgresql.largeobject.LargeObject is - returned, and its methods then allow access to the object. - - - - This class can only be created by org.postgresql.PGConnection. To - get access to this class, use the following segment of code: - -import org.postgresql.largeobject.*; -Connection conn; -LargeObjectManager lobj; -// ... code that opens a connection ... -lobj = ((org.postgresql.PGConnection)myconn).getLargeObjectAPI(); - - - - - Normally, client code would use the BLOB - methods to access large objects. However, sometimes - lower level access to Large Objects is required, that is not - supported by the JDBC specification. - - - - Refer to org.postgresql.largeobject.LargeObject on how to - manipulate the contents of a Large Object. - - - - Variables - - - - public static final int WRITE - - This mode indicates we want to write to an object. - - - - - public static final int READ - - This mode indicates we want to read an object. - - - - - public static final int READWRITE - - This mode is the default. It indicates we want read and write access to a large object. - - - - - - - Methods - - - - -public LargeObject open(int oid) throws SQLException - - - This opens an existing large object, based on its OID. This - method assumes that READ and - WRITE access is required (the default). - - - - - -public LargeObject open(int oid, - int mode) throws SQLException - - - This opens an existing large object, based on its OID, and - allows setting the access mode. - - - - - -public int create() throws SQLException - - - This creates a large object, returning its OID. - It defaults to READWRITE for the new object's attributes. - - - - - -public int create(int mode) throws SQLException - - - This creates a large object, returning its OID, and sets the - access mode. - - - - - -public void delete(int oid) throws SQLException - - - This deletes a large object. - - - - - -public void unlink(int oid) throws SQLException - - - This deletes a large object. It is identical to the delete - method, and is supplied as the C API uses - unlink. - - - - - - - - - - - - Using the Driver in a Multithreaded or a Servlet Environment - - - threads - with JDBC - - - - A problem with many JDBC drivers is that only - one thread can use a Connection at any one - time --- otherwise a thread could send a query while another one is - receiving results, and this could cause severe confusion. - - - - The PostgreSQL JDBC driver - is thread safe. - Consequently, if your application uses multiple threads then you do - not have to worry about complex algorithms to ensure that only one thread - uses the database at a time. - - - - If a thread attempts to use the connection while another one is - using it, it will wait until the other thread has finished its - current operation. If the operation is a regular SQL - statement, then the operation consists of sending the statement and - retrieving any ResultSet (in full). If it - is a fast-path call (e.g., reading a block - from a large object) then it consists of - sending and retrieving the respective data. - - - - This is fine for applications and applets but can cause a - performance problem with servlets. If you have several threads - performing queries then each but one will pause. - To solve this, you are advised to create a pool of connections. - When ever a thread needs to use the database, it asks a manager - class for a Connection object. The manager - hands a free connection to the thread and marks it as busy. If a - free connection is not available, it opens one. Once the thread - has finished using the connection, it returns it to the manager - which can then either close it or add it to the pool. The manager - would also check that the connection is still alive and remove it - from the pool if it is dead. The down side of a connection pool is - that it increases the load on the server because a new session is - created for each Connection object. It is - up to you and your applications' requirements. - - - - - Connection Pools and Data Sources - - - connection pool - in JDBC - - - - DataSource - - - - JDBC 2 introduced standard connection pooling features in an - add-on API known as the JDBC 2.0 Optional - Package (also known as the JDBC 2.0 - Standard Extension). These features have since been included in - the core JDBC 3 API. The - PostgreSQL JDBC drivers - support these features if it has been compiled with - JDK 1.3.x in combination with the - JDBC 2.0 Optional Package - (JDBC 2), or with JDK 1.4 or higher - (JDBC 3). Most application servers include - the JDBC 2.0 Optional Package, but it is - also available separately from the Sun - JDBC download site. - - - - Overview - - - The JDBC API provides a client - and a server interface for connection pooling. The client - interface is javax.sql.DataSource, - which is what application code will typically use to - acquire a pooled database connection. The server interface - is javax.sql.ConnectionPoolDataSource, - which is how most application servers will interface with - the PostgreSQL JDBC - driver. - - - - In an application server environment, the - application server configuration will typically refer to - the PostgreSQL - ConnectionPoolDataSource implementation, - while the application component code will typically acquire a - DataSource implementation provided by - the application server (not by - PostgreSQL). - - - - For an environment without an application server, - PostgreSQL provides two implementations - of DataSource which an application can use - directly. One implementation performs connection pooling, - while the other simply provides access to database connections - through the DataSource interface without - any pooling. Again, these implementations should not be used - in an application server environment unless the application - server does not support the - ConnectionPoolDataSource interface. - - - - - Application Servers: <classname>ConnectionPoolDataSource</classname> - - - PostgreSQL includes one implementation - of ConnectionPoolDataSource for - JDBC 2 and one for JDBC 3, - as shown in . - - - - - <classname>ConnectionPoolDataSource</classname> Implementations - - - - - JDBC - Implementation Class - - - - - - 2 - org.postgresql.jdbc2.optional.ConnectionPool - - - - 3 - org.postgresql.jdbc3.Jdbc3ConnectionPool - - - -
- - - Both implementations use the same configuration scheme. - JDBC requires that a - ConnectionPoolDataSource be configured via - JavaBean properties, shown in , - so there are get and set methods for each of these properties. - - - - <classname>ConnectionPoolDataSource</> Configuration Properties - - - - - Property - Type - Description - - - - - - serverName - String - PostgreSQL database server - host name - - - - databaseName - String - PostgreSQL database name - - - - portNumber - int - - TCP port which the PostgreSQL - database server is listening on (or 0 to use the default port) - - - - - user - String - User used to make database connections - - - - password - String - Password used to make database connections - - - - defaultAutoCommit - boolean - - Whether connections should have autocommit enabled or disabled - when they are supplied to the caller. The default is - false, to disable autocommit. - - - - -
- - - Many application servers use a properties-style syntax to - configure these properties, so it would not be unusual to enter - properties as a block of text. If the application server provides - a single area to enter all the properties, they might be listed - like this: - -serverName=localhost -databaseName=test -user=testuser -password=testpassword - - Or, if semicolons are used as separators instead of newlines, it - could look like this: - -serverName=localhost;databaseName=test;user=testuser;password=testpassword - - - - - - - Applications: <classname>DataSource</> - - PostgreSQL includes two - implementations of DataSource - for JDBC 2 and two for JDBC - 3, as shown in . - The pooling implementations do not actually close connections - when the client calls the close method, but - instead return the connections to a pool of available connections - for other clients to use. This avoids any overhead of repeatedly - opening and closing connections, and allows a large number of - clients to share a small number of database connections. - The pooling data-source implementation provided here is not - the most feature-rich in the world. Among other things, - connections are never closed until the pool itself is closed; - there is no way to shrink the pool. As well, connections - requested for users other than the default configured user are - not pooled. Many application servers - provide more advanced pooling features and use the - ConnectionPoolDataSource implementation - instead. - - - <classname>DataSource</> Implementations - - - - - JDBC - Pooling - Implementation Class - - - - - - 2 - No - org.postgresql.jdbc2.optional.SimpleDataSource - - - - 2 - Yes - org.postgresql.jdbc2.optional.PoolingDataSource - - - - 3 - No - org.postgresql.jdbc3.Jdbc3SimpleDataSource - - - - 3 - Yes - org.postgresql.jdbc3.Jdbc3PoolingDataSource - - - - -
- - - All the implementations use the same configuration scheme. - JDBC requires that a - DataSource be configured via JavaBean - properties, shown in , so there - are get and set methods for each of these properties. - - - - <classname>DataSource</> Configuration Properties - - - - - Property - Type - Description - - - - - - serverName - String - PostgreSQL database server - host name - - - - databaseName - String - PostgreSQL database name - - - - portNumber - int - TCP port which the - PostgreSQL database server is - listening on (or 0 to use the default port) - - - - user - String - User used to make database connections - - - - password - String - Password used to make database connections - - - -
- - The pooling implementations require some additional - configuration properties, which are shown in . - - - Additional Pooling <classname>DataSource</> Configuration Properties - - - - - Property - Type - Description - - - - - - dataSourceName - String - Every pooling DataSource must have a - unique name. - - - - initialConnections - int - The number of database connections to be created - when the pool is initialized. - - - - maxConnections - int - The maximum number of open database connections to - allow. When more connections are requested, the caller - will hang until a connection is returned to the pool. - - - -
- - shows an example of typical application code using a - pooling DataSource. - - - <literal>DataSource</literal> Code Example - - - Code to initialize a pooling DataSource might look like this: - -Jdbc3PoolingDataSource source = new Jdbc3PoolingDataSource(); -source.setDataSourceName("A Data Source"); -source.setServerName("localhost"); -source.setDatabaseName("test"); -source.setUser("testuser"); -source.setPassword("testpassword"); -source.setMaxConnections(10); - - Then code to use a connection from the pool might look - like this. Note that it is critical that the connections - are eventually closed. Else the pool will leak connections and - will eventually lock all the clients out. - -Connection con = null; -try { - con = source.getConnection(); - // use connection -} catch (SQLException e) { - // log error -} finally { - if (con != null) { - try { con.close(); } catch (SQLException e) {} - } -} - - - - - - - Data Sources and <acronym>JNDI</acronym> - - - JNDI - - - - All the ConnectionPoolDataSource and - DataSource implementations can be stored - in JNDI. In the case of the nonpooling - implementations, a new instance will be created every time the - object is retrieved from JNDI, with the - same settings as the instance that was stored. For the - pooling implementations, the same instance will be retrieved - as long as it is available (e.g., not a different - JVM retrieving the pool from - JNDI), or a new instance with the same - settings created otherwise. - - - - In the application server environment, typically the - application server's DataSource instance - will be stored in JNDI, instead of the - PostgreSQL - ConnectionPoolDataSource implementation. - - - - In an application environment, the application may store - the DataSource in JNDI - so that it doesn't have to make a reference to the - DataSource available to all application - components that may need to use it. An example of this is - shown in . - - - - <classname>DataSource</classname> <acronym>JNDI</acronym> Code Example - - - Application code to initialize a pooling DataSource and add - it to JNDI might look like this: - -Jdbc3PoolingDataSource source = new Jdbc3PoolingDataSource(); -source.setDataSourceName("A Data Source"); -source.setServerName("localhost"); -source.setDatabaseName("test"); -source.setUser("testuser"); -source.setPassword("testpassword"); -source.setMaxConnections(10); -new InitialContext().rebind("DataSource", source); - - Then code to use a connection from the pool might look - like this: - -Connection con = null; -try { - DataSource source = (DataSource)new InitialContext().lookup("DataSource"); - con = source.getConnection(); - // use connection -} catch (SQLException e) { - // log error -} catch (NamingException e) { - // DataSource wasn't found in JNDI -} finally { - if (con != null) { - try { con.close(); } catch (SQLException e) {} - } -} - - - - - - - - - Further Reading - - - If you have not yet read it, you are advised you read the - JDBC API Documentation - (supplied with Sun's JDK) and the - JDBC Specification. Both are available from - . - - - - - contains updated information not included in this chapter and - also offers precompiled drivers. - - - - - diff --git a/doc/src/sgml/postgres.sgml b/doc/src/sgml/postgres.sgml index 2fbbf40130..7e2e76de70 100644 --- a/doc/src/sgml/postgres.sgml +++ b/doc/src/sgml/postgres.sgml @@ -1,5 +1,5 @@ diff --git a/src/Makefile.global.in b/src/Makefile.global.in index 68c3bf8078..f3a1d39182 100644 --- a/src/Makefile.global.in +++ b/src/Makefile.global.in @@ -1,5 +1,5 @@ # -*-makefile-*- -# $PostgreSQL: pgsql/src/Makefile.global.in,v 1.172 2003/12/19 23:29:15 momjian Exp $ +# $PostgreSQL: pgsql/src/Makefile.global.in,v 1.173 2004/01/19 21:20:06 tgl Exp $ #------------------------------------------------------------------------------ # All PostgreSQL makefiles include this file and use the variables it sets, @@ -111,7 +111,6 @@ override docdir := $(docdir)/postgresql endif endif -javadir := $(DESTDIR)$(datadir)/java localedir := @localedir@ @@ -121,7 +120,6 @@ localedir := @localedir@ # # Records the choice of the various --enable-xxx and --with-xxx options. -with_java = @with_java@ with_perl = @with_perl@ with_python = @with_python@ with_tcl = @with_tcl@ @@ -209,7 +207,6 @@ perl_embed_ldflags = @perl_embed_ldflags@ # Miscellaneous -ANT = @ANT@ AWK = @AWK@ LN_S = @LN_S@ MSGFMT = @MSGFMT@ diff --git a/src/interfaces/Makefile b/src/interfaces/Makefile index 052d66dd14..1fa91d5375 100644 --- a/src/interfaces/Makefile +++ b/src/interfaces/Makefile @@ -4,7 +4,7 @@ # # Copyright (c) 1994, Regents of the University of California # -# $PostgreSQL: pgsql/src/interfaces/Makefile,v 1.51 2003/11/29 19:52:08 pgsql Exp $ +# $PostgreSQL: pgsql/src/interfaces/Makefile,v 1.52 2004/01/19 21:20:06 tgl Exp $ # #------------------------------------------------------------------------- @@ -14,16 +14,12 @@ include $(top_builddir)/src/Makefile.global DIRS := libpq ecpg -ALLDIRS := $(DIRS) libpgtcl jdbc +ALLDIRS := $(DIRS) libpgtcl ifeq ($(with_tcl), yes) DIRS += libpgtcl endif -ifeq ($(with_java), yes) -DIRS += jdbc -endif - all install installdirs uninstall dep depend distprep: @for dir in $(DIRS); do $(MAKE) -C $$dir $@ || exit; done diff --git a/src/makefiles/Makefile.cygwin b/src/makefiles/Makefile.cygwin index 0449313276..b3ee00c09e 100644 --- a/src/makefiles/Makefile.cygwin +++ b/src/makefiles/Makefile.cygwin @@ -1,4 +1,4 @@ -# $PostgreSQL: pgsql/src/makefiles/Makefile.cygwin,v 1.3 2003/11/29 19:52:12 pgsql Exp $ +# $PostgreSQL: pgsql/src/makefiles/Makefile.cygwin,v 1.4 2004/01/19 21:20:06 tgl Exp $ DLLTOOL= dlltool DLLWRAP= dllwrap BE_DLLLIBS= -L$(top_builddir)/src/backend -lpostgres @@ -32,6 +32,4 @@ ifneq (,$(findstring src/pl/plpython,$(subdir))) override CPPFLAGS+= -DUSE_DL_IMPORT endif -override javadir := '$(shell cygpath -w $(javadir))' - sqlmansect = 7