//: containers/References.java

package containers; /* Added by Eclipse.py */

// Demonstrates Reference objects

import java.lang.ref.*;

import java.util.*;

class VeryBig {

private static final int SIZE = 10000;

private long[] la = new long[SIZE];

private String ident;

public VeryBig(String id) { ident = id; }

public String toString() { return ident; }

protected void finalize() {

System.out.println("Finalizing " + ident);

}

}

public class References {

private static ReferenceQueue<VeryBig> rq =

new ReferenceQueue<VeryBig>();

public static void checkQueue() {

Reference<? extends VeryBig> inq = rq.poll();

if(inq != null)

System.out.println("In queue: " + inq.get());

}

public static void main(String[] args) {

int size = 10;

// Or, choose size via the command line:

if(args.length > 0)

size = new Integer(args[0]);

LinkedList<SoftReference<VeryBig>> sa =

new LinkedList<SoftReference<VeryBig>>();

for(int i = 0; i < size; i++) {

sa.add(new SoftReference<VeryBig>(

new VeryBig("Soft " + i), rq));

System.out.println("Just created: " + sa.getLast());

checkQueue();

}

LinkedList<WeakReference<VeryBig>> wa =

new LinkedList<WeakReference<VeryBig>>();

for(int i = 0; i < size; i++) {

wa.add(new WeakReference<VeryBig>(

new VeryBig("Weak " + i), rq));

System.out.println("Just created: " + wa.getLast());

checkQueue();

}

SoftReference<VeryBig> s =

new SoftReference<VeryBig>(new VeryBig("Soft"));

WeakReference<VeryBig> w =

new WeakReference<VeryBig>(new VeryBig("Weak"));

System.gc();

LinkedList<PhantomReference<VeryBig>> pa =

new LinkedList<PhantomReference<VeryBig>>();

for(int i = 0; i < size; i++) {

pa.add(new PhantomReference<VeryBig>(

new VeryBig("Phantom " + i), rq));

System.out.println("Just created: " + pa.getLast());

checkQueue();

}

}

} /* (Execute to see output) *///:~