11. Installing the IBM Developer Kit for Java
This section gives you quick and dirty instructions on how to install the IBM Developer Kit for Java, version 1.1.8 or 1.3. You need the IBM Developer Kit for Java to run the DB2 Control Center or Java applications or applets that connect to DB2. Note that these instructions are not meant to replace the documentation supplied with the IBM Developer Kit for Java.
 | For DB2 Version 7.1, you cannot use other versions of Java. Versions of the Java Virtual Machine (JVM) supplied by other software organizations are not supported. |
Installing the IBM Developer Kit for Java, Version 1.1.8
Download the IBM Developer Kit for Java, version 1.1.8, from the IBM Java Developer's Kit downloads web site. I'll assume that you download the RPM package of the IBM Developer Kit for Java.
Install the IBM Developer Kit for Java by issuing the following command as root:
bash# rpm -ivh IBMJava118-SDK-1.1.8-2.0-i386.rpm
I most recently tested IBM JDK 1.1.8 build 20010115a successfully on Red Hat 6.2. To see which build of the IBM JDK you are using, issue the java -fullversion command.
Add the following lines to your /etc/profile file to set up the Java environment for all users:
export JAVA_HOME=/usr/jdk118 export PATH=$PATH:$JAVA_HOME/bin export CLASSPATH=$CLASSPATH:$JAVA_HOME/lib/classes.zip
Caldera users should see Section 3.1.1 for instructions on configuring the IBM Developer Kit for Java on Caldera OpenLinux.
Red Hat 7.1 enabled a floating stack feature in the glibc library that breaks the IBM JDK 1.1.8. Other distributions might follow their lead. If the DB2 Control Center refuses to start successfully or your Java applications do not work, you can disable the floating stack by setting the LD_ASSUME_KERNEL environment variable to 2.2.5 before running the DB2 Control Center as follows:
It would probably be wise to include these commands in the sqllib/db2profile script of your instance user so that you always inherit these settings.bash$ export LD_ASSUME_KERNEL=2.2.5 bash$ db2set DB2ENVLIST=LD_ASSUME_KERNEL
Installing the IBM Developer Kit for Java, Version 1.3
Download the IBM Developer Kit for Java, version 1.3, from the IBM Java Developer's Kit downloads web site. I'll assume that you download the RPM package of the IBM Developer Kit for Java.
Install the IBM Developer Kit for Java by issuing the following command as root:
bash# rpm -ivh IBMJava2-SDK-1.3-1.1-i386.rpm
I most recently tested build cx130-20010329 successfully with Red Hat 7.1. To see which build of the IBM JDK you are using, issue the java -fullversion command.
Add the following lines to your /etc/profile file to set up the Java environment for all users:
export PATH=$PATH:/opt/IBMJava2-13/jre/bin
Caldera users should see Section 3.1.1 for instructions on configuring the IBM Developer Kit for Java on Caldera OpenLinux.
IBM JDK 1.3 does away with the jre command, even if you install the the IBM JRE 1.3 package. However, the db2cc script calls the jre command. The easiest solution is to create a link called jre to the java executable in the /opt/IBMJava2-13/bin directory by issuing the following command as root.
bash# ln -sf /opt/IBMJava2-13/jre/bin/java /opt/IBMJava2-13/jre/bin/jre
The db2cc script calls the jre command with the -nojit argument, which is not supported in IBM JDK 1.3. Remove the option by changing line 44 of /usr/IBMdb2/V7.1/bin/db2cc to the following:
JRE_OPTIONS="-ss256k -mx128m -Ddb2path=$DB2PATH"