回调函数

public interface ICallback {
  public void   func();
}
   
public class ClassWithCallbackFunction implements ICallback{
  public ClassWithCallbackFunction() {
  }
  public void func(){
    System.out.println("cccccccccccccccccc");
  }
}
   
public class Caller {
  ICallback callback;
  public void doCallback() {
    callback.func();
  }

  public void setCallback(ICallback callback) {
    this.callback = callback;
  }

}
    
public class MainClass {
  public MainClass() {
  }

  public static void main(String[] args) {
    Caller caller = new Caller();
    caller.setCallback(new ClassWithCallbackFunction() {
      public void func() {
        System.out.println("aaaaaaaaaa");
      }
    });
    caller.doCallback();
  }
}