The runtime behavior of the libgcj library can be modified by setting
certain system properties. These properties can be compiled into the program
using the -Dname[=value] option to gcj or by
setting them explicitly in the program by calling the
java.lang.System.setProperty() method. Some system properties are only
used for informational purposes (like giving a version number or a user name).
A program can inspect the current value of a property by calling the
java.lang.System.getProperty() method.