The platform-specific support jar.
The platform-specific support jar.
Usually this is tools.jar in the jdk/lib directory of the platform distribution.
The file location is determined by probing the lib directory under JDK_HOME or JAVA_HOME, if one of those environment variables is set, then the lib directory under java.home, and finally the lib directory under the parent of java.home. Or, as a last resort, search deeply under those locations (except for the parent of java.home, on the notion that if this is not a canonical installation, then that search would have little chance of succeeding).
Locations discovered by supplemental heuristics.