Java Tutorial/Development/JNI
If the DLL is in the CLASSPATH then you don"t need to specify a PATH.
Runtime.getRuntime().load("d:/directoryX/subDirY/MyDll.dll");
Load a DLL
System.loadLibrary("d:\\directoryX\\subDirY\\MyDll.dll")
Specify through the JVM command line the location where to find the JNI DLL to be loaded
java -Djava.library.path=c:/JNI