Download Java Stored Procedures - Getting the Environment Ready

Java Stored Procedures Getting the Environment
Ready
John Lantz
Federal Reserve Board
June 11, 2008
Agenda for today
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What is Java, background information
Java and DB2
Implementing Java on the mainframe
Building a procedure via Development
Center
Tips, resources, etc…
Java – why use it?
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A platform independent object oriented
programming language
Richer programming language then SQL
Procedure Language
Compile it once and deploy it anywhere
Java – what is it?
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You have two options on how to deploy
JDBC or SQLJ
JDBC
SQLJ
Dynamic SQL
Easier to write
Errors detected at RUN
time
Static SQL
Faster run time
Stable access paths
Errors detected at BIND
time
Easy monitoring
Java – example (JDBC)
/**
* JDBC Stored Procedure M1JPL01.test_java_jdbc
*/
package PKG80503035400970;
import java.sql.*;
// JDBC classes
public class Test_java_jdbc
{
public static void test_java_jdbc ( ResultSet[] rs1 ) throws SQLException, Exception
{
// Get connection to the database
Connection con = DriverManager.getConnection("jdbc:default:connection");
PreparedStatement stmt = null;
boolean bFlag;
String sql;
sql = "SELECT SCHEMA, NAME FROM SYSIBM.SYSROUTINES";
stmt = con.prepareStatement( sql );
bFlag = stmt.execute();
rs1[0] = stmt.getResultSet();
}
Java – example (SQLJ)
/**
* SQLJ Stored Procedure M1JPL01.test_java_sqlj
*/
package PKG80503035149340;
import java.sql.*;
// JDBC classes
import sqlj.runtime.*;
import sqlj.runtime.ref.*;
#sql context SPContext;
#sql iterator Test_java_sqlj_Cursor1 ( String, String );
public class Test_java_sqlj
{
public static void test_java_sqlj ( ResultSet[] rs1 ) throws SQLException, Exception
{
Test_java_sqlj_Cursor1 cursor1 = null;
SPContext ctx = null;
try
{
ctx = new SPContext( "jdbc:default:connection", false );
#sql [ctx] cursor1 =
{
SELECT SCHEMA, NAME FROM SYSIBM.SYSROUTINES
};
rs1[0] = cursor1.getResultSet();
}
catch (SQLException e)
{
// Close open resources
try
{
if (cursor1 != null) cursor1.close()
} catch (SQLException e2) { /* ignore */ };
throw e;
}
}
}
Java – Which to use?
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One reason why you use stored procedures is to
have code that is efficient as possible
This is accomplished by static SQL – thus avoiding
overhead of prepare/etc… at execution time
Using JDBC – kind of defeats the purpose of a
stored procedure…
Tasks for z/OS System
Programmer
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Install JDBC/SQLJ Drivers
Set up WLM environment
Set up UNIX system services
Required DB2 changes
Installing drivers
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Part of DB2 base code: FMID JDB8812
Jobs DSNDDEF2 and DSNISMKD
DSNDDEF2 - creates necessary DDDEF for
DB2 universal drivers
DSNISMKD - allocates the HFS structures
(both jobs are smp/e stuff)
WLM setup…
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Set up RRS (Resource Recovery Service)
DESCSTAT=YES in DSNZPARM (necessary for
SQLJ support)
Set NUMTCB=5 for java WLM. Initially set to 1, not
to exceed 8.
Make sure //JAVAENV DD statement is correct
WLM environment should be dedicated to Java
stored procedures (don’t mix COBOL and SQL)
WLM setup… (continued)
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Don’t confuse the WLM environments.
In our environment…
DSNUWLM1 and DSNUJAV1
DSN…WLM1 is used in the build process
(issues the refresh command)
DSN…JAV1 is where the procedures execute
(where the procedure executes)
WLM setup… (continued)
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Sample DD statements within the Java WLM address space. The
JAVAENV specifies the LE run-time options for Java routines
//JAVAENV DD DSN=SYS2.DB2.DEVU.DSNUJAV1.JSPENV
//JAVAERR DD PATH='/usr/lpp/dsnu/jsppuser/JAVAERR.TXT',
PATHOPTS=(ORDWR,OCREAT,OAPPEND),
PATHMODE=(SIRUSR,SIWUSR,SIRGRP,SIWGRP,SIROTH,SIWOTH)
//JAVAOUT DD PATH='/usr/lpp/dsnu/jsppuser/JAVAOUT.TXT',
PATHOPTS=(ORDWR,OCREAT,OAPPEND),
PATHMODE=(SIRUSR,SIWUSR,SIRGRP,SIWGRP,SIROTH,SIWOTH)
UNIX stuff…
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Set up UNIX environment
LIBPATH, CLASSPATH, PATH, etc…
(remember some UNIX is case sensitive)
DB2_HOME (where JDBC driver is installed)
JAVA_HOME
Per IBM, we must install Java 31-bit version
software on the z/OS 1.8 system and the
JAVA_HOME must point to the 31 bit Java
version.
(remember some UNIX is case sensitive)
Installing / configuring DB2
components
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DSNTIJSG – creates various stored procedures
(grant execute to PUBLIC)
SQLJ.DB2_INSTALL_JAR,
SQLJ.DB2_REPLACE_JAR
SQLJ.DB2_REMOVE_JAR
SQLJ.DB2_UPDATEJARINFO
DSNJDBC and DSNJAR collection’s
perform GRANT CREATE ON COLLECTION… as
necessary
DSNTIJMS – creates additional indexes and catalog
objects (may have been run in V7…, check)
Installing / configuring DB2
components
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To use Development Center, must have
SELECT on the following tables…
SYSIBM.SYSDUMMY1
SYSIBM.SYSROUTINES
SYSIBM.SYSPARMS
SYSIBM.SYSJARCONTENTS
SYSIBM.SYSJAROBJECTS
SYSIBM.SYSJAVAOPTSDSNTIJSG
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Individual users do not need their own profiles
set up within UNIX
Building a procedure
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Things the programmer needs to know before
building a procedure via the Development
Center
- Proper Java WLM environment
- Proper collection to use, and the necessary
GRANT CREATE ON COLLECTION…
Building a procedure (cont)
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Do not check “Build using DSNTJSPP” on
the z/OS Options panel. This is for the
Legacy Driver type 2, not the Universal Driver
type 2.
Java – Define DDL for procedure
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This gets created for you….
CREATE PROCEDURE M1JPL01.TEST_JAVA_SQLJ
( IN INP_PARM VARCHAR(128)
CCSID EBCDIC )
RESULT SETS
1
EXTERNAL NAME
M1JPL01.SQL80503035149340:PKG80503035149340.Test_java_sqlj.test_java_sqlj'
LANGUAGE
JAVA
PARAMETER STYLE JAVA
NOT DETERMINISTIC
NULL CALL
FENCED
MODIFIES SQL DATA
NO DBINFO
COLLID
DSNJDBC
WLM ENVIRONMENT DSNUJAV1
PROGRAM TYPE SUB
COMMIT ON RETURN NO ;
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External name refers to java classname.methodname
Experiences…
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Still in the exploratory mode.
It’s working and available for the developers
Performance has been good so far
Recommended resources
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Information Center
http://publib.boulder.ibm.com/infocenter/dzichelp/v2r
2/index.jsp
DB2 for z/OS and OS/390: Ready for Java
SG24-6435-00
DB2 for z/OS Stored Procedures :
Through the CALL and Beyond
SG24-7083-00
Application Programming Guide and Reference
for Java
SC18-7414-05