java回调机制的实现方式

回调机制在java中应用非常广泛，下面用一个demo简单的实现回调机制

1.Time.java

package com.test;

public class Time {

    private OnTimeChange mOnTimeChange;

    private int time;

/*接口*/

    public interface OnTimeChange{

        public void timChange();

    }

/*监听事件*/

    public void setOnTimeChangeListener(OnTimeChange change){

        mOnTimeChange=change;

    }

    public void setTime(int value){

         time=value;

        mOnTimeChange.timChange();

    }

}

2.Caller.java

public class Caller extends Activity implements OnTimeChange {

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        // TODO Auto-generated method stub

        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        Time time=new Time();

        time.setOnTimeChangeListener(this);//监听事件

        time.setTime(1);

/*匿名内部类实现接口*/   

time.setOnTimeChangeListener(new OnTimeChange() {

           

            @Override

            public void timChange() {

                // TODO Auto-generated method stub

                Log.i("debug", "time has changed");

            }

        });

    }

    @Override

    public void timChange() {

        // TODO Auto-generated method stub

        Log.i("debug", "Time has changed");

    }

}