//: 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 rq =
new ReferenceQueue();
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> sa =
new LinkedList>();
for(int i = 0; i < size; i++) {
sa.add(new SoftReference(
new VeryBig("Soft " + i), rq));
System.out.println("Just created: " + sa.getLast());
checkQueue();
}
LinkedList> wa =
new LinkedList>();
for(int i = 0; i < size; i++) {
wa.add(new WeakReference(
new VeryBig("Weak " + i), rq));
System.out.println("Just created: " + wa.getLast());
checkQueue();
}
SoftReference s =
new SoftReference(new VeryBig("Soft"));
WeakReference w =
new WeakReference(new VeryBig("Weak"));
System.gc();
LinkedList> pa =
new LinkedList>();
for(int i = 0; i < size; i++) {
pa.add(new PhantomReference(
new VeryBig("Phantom " + i), rq));
System.out.println("Just created: " + pa.getLast());
checkQueue();
}
}
} /* (Execute to see output) *///:~