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

publicinterface doJob

{

     publicvoid fillBlank(inta, int b, int result);

}

//计算器公共类

publicclass SuperCalculator

{

    publicvoid add(inta, int b, doJob  customer)

{

        intresult = a + b;

        customer.fillBlank(a, b, result);

}

}

//学生使用计算器

publicclass Student
{
    privateString name = null;
 
    publicStudent(String name)
    {
        // TODO Auto-generated constructor stub
        this.name = name;
    }
 
    publicvoid setName(String name)
    {
        this.name = name;
    }
 
    publicclass doHomeWork implements doJob
    {
 
        @Override
        publicvoid fillBlank(inta, int b, int result)
        {
            // TODO Auto-generated method stub
            System.out.println(name + "求助小红计算:" + a + " + " + b + " = " + result);
        }
 
    }
 
    publicvoid callHelp (inta, int b)
    {
        newSuperCalculator().add(a, b, new doHomeWork());
    }
}
//商家使用计算器
publicclass Seller
{
    privateString name = null;
 
    publicSeller(String name)
    {
        // TODO Auto-generated constructor stub
        this.name = name;
    }
 
    publicvoid setName(String name)
    {
        this.name = name;
    }
 
    publicclass doHomeWork implements doJob
    {
 
        @Override
        publicvoid fillBlank(inta, int b, int result)
        {
            // TODO Auto-generated method stub
            System.out.println(name + "求助小红算账:" + a + " + " + b + " = " + result + "元");
        }
 
    }
 
    publicvoid callHelp (inta, int b)
    {
        newSuperCalculator().add(a, b, new doHomeWork());
    }
}
//测试类，main方法
publicclass Test
{
    publicstatic void main(String[] args)
    {
        inta = 56;
        intb = 31;
        intc = 26497;
        intd = 11256;
        Student s1 = new Student("小明");
        Seller s2 = new Seller("老婆婆");
 
        s1.callHelp(a, b);
        s2.callHelp(c, d);
    }
}

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