javald and Relocatable Applications

Correct execution of many Java applications depends on the values of the JAVA_HOME, CLASSPATH, and LD_LIBRARY_PATH environment variables. Because the values of these environment variables are controlled by each user, they can be set to arbitrary paths, with either path being unusual. Further, it is common for an application to require a unique value in the CLASSPATH variable.

javald(1) is a command that generates wrappers for Java applications. The wrapper can specify the correct paths for any or all of the JAVA_HOME, CLASSPATH, and LD_LIBRARY_PATH environment variables. It does so with no effect on the user's values of these environment variables. It also overrides the user's values for these environment variables during execution of the Java application. Further, the wrapper ensures that the specified paths are not bound until the Java application is actually executed, which maximizes relocatability of applications.