Sample Java class to simulate the Javascript callback functionality

Callbackable.java

/**
 * Sample class that define a Callbackable object to act like a Javascript callback function
 */
 
package net.fabiocigliano.test.callback;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;

/**
 * @author fabiocigliano
 */
public class Callbackable implements Runnable {
	
	private Method method;
	private Object receiver;
	private Class<?> creceiver;
	private Object[] params;
	
	private static Object[] NIL = new Object[]{};
	
	/*
	 * Constructors
	 */
	
	public Callbackable(Method m, Class<?> receiver) {
		this.method = m;
		setReceiver(receiver);
		setParam(NIL);
	}
	
	public Callbackable(Method m, Object receiver) {
		this.method = m;
		setReceiver(receiver);
		setParam(NIL);
	}
	
	public Callbackable(Method m, Class<?> receiver, Object... params) {
		this.method = m;
		creceiver = receiver;
		this.receiver = null;
		setParam(params);
	}
	
	/*
	 * Setters
	 */
	
	public void setParam(Object...params) {
		this.params = params;
	}
	
	public void setReceiver(Object o) {
		if( o != null ) {
			receiver = o;
			creceiver = o.getClass();
		}
	}
	
	public void setReceiver(Class<?> c) {
		if( c != null ) {
			receiver = null;
			creceiver = c;
		}
	}
	
	/*
	 * Status methods
	 */
	
	public boolean canRun() {
		return this.method != null && (this.receiver!=null || this.creceiver!=null);
	}
	
	protected static void handleException(Exception e) {
		e.printStackTrace();
	}
	
	private static Method findMethod(Class<?> c, String methodName) {
		Method m = null; 
		try {
			for(Method list : c.getMethods()) {
				System.out.println(list);
				if( list.getName().equals(methodName) ) {
					m = list;
//					break;
				}
			}
		} catch(SecurityException npe) {
			handleException(npe);
		}
		return m;
	}
	
	/*
	 * Final callback method
	 */
	
	@Override public void run() {
		try {
			if( canRun() ) {
				if(Modifier.isStatic(method.getModifiers())) {
					this.method.invoke(null, params);
				} else {
					if( receiver == null ) {
						receiver = creceiver.newInstance();
					}
					this.method.invoke(receiver, params);
				}
			}
		}
		catch(IllegalAccessException iae) {
			handleException(iae);
		}
		catch(SecurityException se) {
			handleException(se);
		}
		catch(InstantiationException ie) {
			handleException(ie);
		}
		catch(NullPointerException npe) {
			handleException(npe);
		}
		catch(IllegalArgumentException iae) {
			handleException(iae);
		}
		catch(InvocationTargetException ite) {
			handleException(ite);
		}
	}
	
	/*
	 * Testing
	 */
	 
	// TODO:
	
	/**
	 * Sample main for testing
	 * @param args
	 */
	public static void main(String[] args) {
		
		final a i = new a();
		
		System.out.println(i);
		i.c();
		System.out.println(i+" pre thread");
		
		final Callbackable cb;
//		cb = new Callbackable( Callbackable.findMethod(a.class, "print"), i);
		cb = new Callbackable( Callbackable.findMethod(a.class, "print"), a.class, i );
		
		new Thread(new Runnable() {
			@Override public void run() {
				for(int j=0; j<10; j++)	i.c();
				cb.run();
			}
		}).start();
		
		System.out.println(i+" thread started");
		
	}
	
	/**
	 * Sample job, just for testing
	 */
	
	public static class a {
		private int b = 0;
		
		public void c() {
			b = b + 1;
		}
		
		@Override public String toString() {
			return "b = "+b;
		}
		
//		public void print() {
//			System.out.println(this);
//		}
		
		public static void print(a o) {
//			o.print();
			System.out.println(o);
		}
		
	};

}