JAVA回调机制(CallBack)

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java 回调机制基本可以描述为：

一个类A调用另一个类B的方法，调用的同时传入必要参数及A的对象；

在B拿到其他参数并处理完后，可以把原参数和结果或其他中间值当做参数，

通过A的对象调用A的方法，这个方法我们称之为回调方法。

回调机制模板：

//实现回调的接口类

public interface doJob

{

      public void fillBlank( int a, int b, int result);

}

//计算器公共类

public class SuperCalculator

{

     public void add( int a, int b, doJob  customer)

     {

         int result = a + b;

         customer.fillBlank(a, b, result);

     }

}

//学生使用计算器

public class Student

{

     private String name = null ;

 

     public Student(String name)

     {

         // TODO Auto-generated constructor stub

         this .name = name;

     }

 

     public void setName(String name)

     {

         this .name = name;

     }

 

     public class doHomeWork implements doJob

     {

 

         @Override

         public void fillBlank( int a, int b, int result)

         {

             // TODO Auto-generated method stub

             System.out.println(name + "求助小红计算:" + a + " + " + b + " = " + result);

         }

 

     }

 

     public void callHelp ( int a, int b)

     {

         new SuperCalculator().add(a, b, new doHomeWork());

     }

}

//商家使用计算器

public class Seller

{

     private String name = null ;

 

     public Seller(String name)

     {

         // TODO Auto-generated constructor stub

         this .name = name;

     }

 

     public void setName(String name)

     {

         this .name = name;

     }

 

     public class doHomeWork implements doJob

     {

 

         @Override

         public void fillBlank( int a, int b, int result)

         {

             // TODO Auto-generated method stub

             System.out.println(name + "求助小红算账:" + a + " + " + b + " = " + result + "元" );

         }

 

     }

 

     public void callHelp ( int a, int b)

     {

         new SuperCalculator().add(a, b, new doHomeWork());

     }

}

//测试类，main方法

public class Test

{

     public static void main(String[] args)

     {

         int a = 56 ;

         int b = 31 ;

         int c = 26497 ;

         int d = 11256 ;

         Student s1 = new Student( "小明" );

         Seller s2 = new Seller( "老婆婆" );

 

         s1.callHelp(a, b);

         s2.callHelp(c, d);

     }

}