tests/gc/NativeWeakRef.java

   1 public class NativeWeakRef {
   2         public native static void setWeakReference(Object o);
   3         public native static Object getWeakReference();
   4         public native static void delWeakReference();
   5
   6         public static void main(String args[]) {
   7                 Object o;
   8                 System.loadLibrary("native");
   9
  10                 /* create the object we want to deal with */
  11                 o = new String("I am not important, you can forget me!");
  12
  13                 /* pass the object to the native world */
  14                 setWeakReference(o);
  15
  16                 /* is the object still there? */
  17                 o = getWeakReference();
  18                 System.out.println(o);
  19
  20                 /* now forget about it and see if it gets collected */
  21                 o = null;
  22                 System.gc();
  23
  24                 /* is the object still there? */
  25                 o = getWeakReference();
  26                 System.out.println(o);
  27
  28                 /* delete the reference inside the native world */
  29                 delWeakReference();
  30         }
  31 }