To use the shared application archive file (appCDS.jsa) with your AppCDS, execute the following command:

    java -Xshare:on 
         -XX:+UseAppCDS 
         -XX:SharedArchiveFile=appCDS.jsa 
         -cp appcds.jar 
         AppCDS  

The preceding code will use the shared application archive file to load the predefined core API classes and application classes to memory. This results in reduced startup time of user applications. The demo application used in this chapter included just four or five classes to demonstrate the process, without overwhelming you. You should be able to notice a considerable reduction in startup time for bigger user applications. Also, you can share the .jsa file between JVMs for a reduced memory footprint.