java:使用匿名类直接new接口

package contract;

public interface ISay {

    void sayHello();
}

package jimmy;
import contract.ISay;
public class Program {
    public static void main(String[] args) {
        ISay say = new ISay() {          
            public void sayHello() {
                System.out.println("Hello java!");
            }
        };
    }
}

package jimmy;

import contract.ISay;
import java.io.PrintStream;

class Program$1 implements ISay
{
  public void sayHello()
  {
    System.out.println("Hello java!");
  }
}