Java回调函数

 

public interface CallBackInterface {                 public void doSome();        public void executeMethod();    }

public class MethodB {        public double getTime(CallBackInterface callBack) {                  long start = System.currentTimeMillis();                  callBack.executeMethod();                  long end = System.currentTimeMillis();

                  System.out.println("cost time=" + (end - start));

                  return end - start;}}

public class MethodA {

public static void main(String[] args) {

MethodB b = new MethodB();

// 返回值d只和MethodB有关，和接口中方法的返回值无关

double d = b.getTime(new CallBackInterface() {

public void executeMethod() {

new MethodA().testMethod();

}

public void doSome() {

}

});

}

}