对于通过WebSocketHandler
使用的实现PerConnectionWebSocketHandler
的类的简单属性注入,我遇到了问题。
此示例在没有@Value
带注释的字段的情况下可以正常工作,但是当我添加@Value
带注释的字段时,当Web套接字连接时,它会失败:java.lang.IllegalStateException: WebSocketHandler not found for StandardWebSocketSession
。
如何获得在@Value
类中注入的MyHandler
字段?
App.java
@SpringBootApplication
@RestController
@EnableWebSocket
public class App implements WebSocketConfigurer {
@Autowired
private BeanFactory beanFactory;
public static void main(String [] args){
SpringApplication.run(App.class, args);
}
@Override
public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
registry.addHandler(myHandler(), "/test").setAllowedOrigins("*");
}
@Bean
public WebSocketHandler myHandler() {
PerConnectionWebSocketHandler perConnectionWebSocketHandler = new PerConnectionWebSocketHandler(MyHandler.class);
perConnectionWebSocketHandler.setBeanFactory(beanFactory);
return perConnectionWebSocketHandler;
}
}
MyHandler.java
@Component
public class MyHandler implements WebSocketHandler{
/* This causes exception
@Value("${injectioneexample}")
private String injectionExample;
*/
@Override
public void handleMessage(WebSocketSession session,
WebSocketMessage<?> encodedMessage) throws Exception {
if (encodedMessage instanceof org.springframework.web.socket.TextMessage) {
org.springframework.web.socket.TextMessage castedTextMessage = (org.springframework.web.socket.TextMessage) encodedMessage;
String message = castedTextMessage.getPayload();
session.sendMessage(new org.springframework.web.socket.TextMessage(message));
System.out.println(message);
}
}
@Override
public void afterConnectionClosed(WebSocketSession arg0, CloseStatus arg1)
throws Exception {
}
@Override
public void afterConnectionEstablished(WebSocketSession arg0)
throws Exception {
//System.out.println("connected " + injectionExample);
}
@Override
public void handleTransportError(WebSocketSession arg0, Throwable arg1)
throws Exception {
}
@Override
public boolean supportsPartialMessages() {
return false;
}
}
application.properties
injectionexample=injected
最佳答案
WebSocketHandler类的属性名称中有一个错字。
@Value("${injectioneexample}")
private String injectionExample;
与在application.properties文件中定义的方式相比,请注意额外的
e
。injectionexample=injected