是否可以在@OnMessage函数中使用POJO而不是字符串?

Question

基本上，我可以使用:

@OnMessage
public void handleMessage(Message message, Session session) {

代替:

@OnMessage
public void handleMessage(String message, Session session) {

消息类看起来像:

public class Message {
private String action;
private String value;
}

Answer 1

根据文档，不可能:

允许的参数有:

Exactly one of any of the following choices
if the method is handling text messages:
String to receive the whole message
Java primitive or class equivalent to receive the whole message converted to that type
String and boolean pair to receive the message in parts
Reader to receive the whole message as a blocking stream
any object parameter for which the endpoint has a text decoder (Decoder.Text or Decoder.TextStream).
if the method is handling binary messages:
byte[] or ByteBuffer to receive the whole message
byte[] and boolean pair, or ByteBuffer and boolean pair to receive the message in parts
InputStream to receive the whole message as a blocking stream
any object parameter for which the endpoint has a binary decoder (Decoder.Binary or Decoder.BinaryStream).
if the method is handling pong messages:
PongMessage for handling pong messages
and Zero to n String or Java primitive parameters annotated with the PathParam annotation for server endpoints.
and an optional Session parameter

https://docs.oracle.com/javaee/7/api/javax/websocket/OnMessage.html

但是如果您使用JAXRS(与RESTEasy, Jersey或CXF)，您将能够使用Json提供程序(Jackson, Gson)直接在目标对象中解析。