return args 如何在 Java 8 中工作？

Question

I'm new to Java8

Can anyone share what return args is returning in below code snippet? How it looks like in Java 7 to understand what's actually happening?

public ApplicationRunner initializeConnection(
        RsvpsWebSocketHandler rsvpsWebSocketHandler) {
           return args -> {
               WebSocketClient rsvpsSocketClient = new StandardWebSocketClient();

               rsvpsSocketClient.doHandshake(
                   rsvpsWebSocketHandler, MEETUP_RSVPS_ENDPOINT);           
           };
       }

Answer 1

It's a lambda , which is just a shorthand initialization of an anonymous class. In Java 1.7 it would look like:

return new ApplicationRunner() {
            @Override
            public void run(ApplicationArguments args) throws Exception {
                WebSocketClient rsvpsSocketClient = new StandardWebSocketClient();

                rsvpsSocketClient.doHandshake(rsvpsWebSocketHandler, MEETUP_RSVPS_ENDPOINT);
            }
        };