實現攔截器主要是在actionInvocation裡面，interceptor在構造方法裝載，然後在invoke方法裡面迴圈載入，每個interceptor裡面invoke下一個interceptor，直到action，然後倒著輸出每個interceptor中invoke後面的方法。

package com.ceair.core.util;

public interface Interceptor {
	public void interceptor(ActionInvocation invocation);
}

package com.ceair.core.util;

public class FirstInterceptor implements Interceptor {

	public void interceptor(ActionInvocation invocation) {
		System.out.println("1");
		invocation.invoke();
		System.out.println("-1");
	}
}
 

package com.ceair.core.util;

public class SecondInterceptor implements Interceptor {

	public void interceptor(ActionInvocation invocation) {
		System.out.println("2");
		invocation.invoke();
		System.out.println("-2");
	}
}

package com.ceair.core.util;

public class Action {
	public void execute() {
		System.out.println("Action");
	}
}
 

package com.ceair.core.util;

import java.util.ArrayList;
import java.util.List;

public class ActionInvocation {
	List<Interceptor> list = new ArrayList<Interceptor>();
	int index = -1;
	Action a = new Action();
	
	public ActionInvocation() {
		this.list.add(new FirstInterceptor());
		this.list.add(new SecondInterceptor());
	}
	
	public void invoke() {
		index ++;
		if (index >= this.list.size()) {
			a.execute();
		} else {
			this.list.get(index).interceptor(this);
		}
	}
}
 

package com.ceair.core.util;

public class Main {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		new ActionInvocation().invoke();
	}

}