关于java 回调的高内聚、低耦合的举例

1.总体更新信息、传递到不同的局部，这里是高内聚

Student student_xuxiaodong = new Student_xuxiaodong();
Teacher teacherA = new Teacher(student_xuxiaodong);
Log.i("CallBack"," start AA  ....  " );
teacherA.askQuestion();

Student mStudent_XuChi = new Student_XuChi();
Teacher teacherB = new Teacher(mStudent_XuChi);
Log.i("CallBack"," start  BB  ....  " );
teacherB.askQuestion();

Student mStudent_XuRong = new Student_XuRong();
Teacher teacherC = new Teacher(mStudent_XuRong);
Log.i("CallBack"," start CC　....  " );
teacherC.askQuestion();

2.解藕

   

//学生告诉老师信息 类
package com.example.myapplication;

public interface Student {
    public void studentTellTeacherInfo(Callback callback);
}

//老师接收学生 信息 类
package com.example.myapplication;
import android.util.Log;
public class Teacher implements Callback {
    private Student student;
    public Teacher(Student student) {
        this.student = student;
    }
        @Override
    public void answerTeacherTime(String name ,String work_time) { //老师只需要回答多久？
        Log.i("CallBack"," 姓名：  " +name);
        Log.i("CallBack"," 知道了，你做作业用时  " +work_time);
    }

    public void askQuestion(){
        student.studentTellTeacherInfo(this);
    }

}

// 学生 Student_XuChi

package com.example.myapplication;

import android.util.Log;

public class Student_XuChi implements Student {
    @Override
    public void studentTellTeacherInfo(Callback callback) {
        try {
            Thread.sleep(5000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        callback.answerTeacherTime("Xu_Chi","5000秒");
        Log.i("CallBack"," start Student_XuChi  " +        callback.hashCode());
    }
}

//学生  Student_XuRong

package com.example.myapplication;

import android.util.Log;

public class Student_XuChi implements Student {
    @Override
    public void studentTellTeacherInfo(Callback callback) {
        try {
            Thread.sleep(5000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        callback.answerTeacherTime("Xu_Chi","5000秒");
        Log.i("CallBack"," start Student_XuChi  " +        callback.hashCode());
    }
}

// 学生  Student_xuxiaodong

package com.example.myapplication;

import android.util.Log;

public class Student_xuxiaodong implements Student {
    @Override
    public void studentTellTeacherInfo(Callback callback) {
        try {
            Thread.sleep(3000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        callback.answerTeacherTime("xuxiaodong","3000秒");
        Log.i("CallBack"," start Student_xuxiaodong  " +        callback.hashCode());
    }

//    @Override
//    public void answerTeacherTime(String name, String work_time) {
//        try {
//            Thread.sleep(3000);
//        } catch (InterruptedException e) {
//            e.printStackTrace();
//        }
//        Callback.
//    }
}

//执行情况

C:\Users\admin>adb logcat -s CallBack
--------- beginning of system
--------- beginning of main
01-30 10:20:37.768  4494  4494 I CallBack:  start AA  ....
01-30 10:20:40.770  4494  4494 I CallBack:  姓名：  xuxiaodong
01-30 10:20:40.770  4494  4494 I CallBack:  知道了，你做作业用时  3000秒
01-30 10:20:40.771  4494  4494 I CallBack:  start Student_xuxiaodong  15652383
01-30 10:20:40.771  4494  4494 I CallBack:  start  BB  ....
01-30 10:20:45.772  4494  4494 I CallBack:  姓名：  Xu_Chi
01-30 10:20:45.772  4494  4494 I CallBack:  知道了，你做作业用时  5000秒
01-30 10:20:45.772  4494  4494 I CallBack:  start Student_XuChi  99143020
01-30 10:20:45.772  4494  4494 I CallBack:  start CC　....
01-30 10:20:53.773  4494  4494 I CallBack:  姓名：  Xu_Chi
01-30 10:20:53.773  4494  4494 I CallBack:  知道了，你做作业用时  8000秒
01-30 10:20:53.773  4494  4494 I CallBack:  start Student_XuRong  4099893