Sun Java System Application Server 8.2 supports both J2SE 1.4.2 and J2SE 5.0 as the underlying JVM. If you want to switch from one J2SE version to another, perform the following general steps. (Windows and Unix)
Download the J2SE SDK (not the JRE) and install it on your system, if you have not already done so.
The J2SE SDK can be downloaded from http://java.sun.com/j2se.
Completely stop the Application Server.
You can use the following command line:
Alternatively, you can use the Administration Console GUI:
Edit the install_dir/config/asenv.conf file (asenv.bat on Windows), changing the value for AS_JAVA to point to the new J2SE home directory.
Edit the as-install/samples/common.properties file, changing the line beginning com.sun.aas.javaRoot... to reference the new J2SE home directory.
Restart the Application Server.
If you are upgrading from a JDK version earlier than the bundled version (JDK 1.4.2_06), then you cannot upgrade to J2SE 5.0 or later using just the steps above. Specifically, in addition to the above steps, you must delete any existing domains and recreate them.