闭包(Closure)和回调

 

interface Teachable
{
    void work();
}
class Programmer
{
    private String name;
    public Programmer(){}
    public Programmer(String name)
    {
    this. name = name;
  }
  public void setName(String name)
  {
    this.name = name;
  }
  public String getName()
  {
    return name;
  }
  public void work()
  {
        System.out.println(name + "再灯下认真敲键盘。。。");
  }
}
//=========================================================
class TeachableProgrammer extends Programmer
{
    public TeachaleProgrammer(){}
    public TeachaleProgrammer(String name)
    {
        super(name);
    }
    private void teach()
    {
        System.out.println(getName() + "教师在讲台上讲解。。。");
    }
    //内部类
    private class Closure implements Teachable
    {
        /*
            非静态内部了类回调外部类实现work方法，非静态内部类引用的作用仅仅是向
            客户类提供一个回调外部类的途径
        */
        public void work()
        {
            teach();
        }
    }
    //返回一个非静态内部类引用，允许外部类通过该非静态内部类引用来回调外部类方法
    public Teachable getCallbackReference()
    {
        return new Closure();
    }
}
public class TeachableProgrammerTest
{
    public static void main(String[] args)
    {
        TeachableProgrammer tp = new TeachableProgrammer("李刚");
        //直接调用TeachableProgrammer类从Programmer类继承到的work方法
        tp.work();
        //表面上调用的是Closure的work方法，实际上是回调TeachableProgrammer的teach方法
        tp.getCallbackReference().work();
    }
}

 

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