java中websocket和Feign使用

JAVA中WebSocket使用

首先导入Jar包

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-websocket</artifactId>
		</dependency>
		// 包含一些需要的WebSocketAPI
		<dependency>
			<groupId>org.apache.tomcat.embed</groupId>
			<artifactId>tomcat-embed-websocket</artifactId>
		</dependency>

配置WebSocket

@Configuration
public class WebSocketConfig {

	@Bean
	public ServerEndpointExporter serverEndpointExporter(){
		return new ServerEndpointExporter();
	}
}

使用

@Component
@ServerEndpoint(value = "/websocket/{uuid}")
public class WebSocketServer {

	private static final Logger LOGGER = LoggerFactory.getLogger(WebSocketServer.class);
	@Resource
	private HttpServletRequest request;

	private Session session;

	private static final ConcurrentHashMap<String, WebSocketServer> websocketMap = new ConcurrentHashMap<>();

	@OnOpen
	public void onOpen(@PathParam("uuid") String uuid, Session session) {
		LOGGER.info("新增uuid==>" + uuid);
		WebSocketServer webSocketServer = new WebSocketServer();
		webSocketServer.session = session;
		websocketMap.put(uuid, webSocketServer);
	}

	@OnClose
	public void onClose(@PathParam("uuid") String uuid) {
		LOGGER.info("移除的uuid==>" + uuid);
		websocketMap.remove(uuid);
	}

	@OnError
	public void onError(Throwable throwable){
		throwable.printStackTrace();
	}

	@OnMessage
	public void send(String message,Session session) throws IOException{
		LOGGER.info("收到来自uuid的消息==>" + message);
	}

	public void sendMessage(String message) {
		LOGGER.info("发送的消息是==>{}",message);
		String cookieStr = request.getSession().getAttribute("uuid").toString();
		LOGGER.info("发送人ID==>{}",cookieStr);
		try {
			 websocketMap.get(cookieStr).session.getBasicRemote().sendText(message);
		} catch (Exception e) {
			throw new RuntimeException(e);
		}
	}
}

一些错误

java.lang.IllegalStateException: Failed to register @ServerEndpoint class: class 
Caused by: javax.websocket.DeploymentException: Cannot deploy POJO class

原因是使用了SpringAOP切面，websocket不能使用Spring中AOP的切面，将使用AOP切面的类移动到其它目录。

注意：在websocket中，如果websocket是在另一个请求中使用的，则在这个请求的过程中，websocket发送的消息将会被阻塞，解决方法是将该请求变为异步操作。
使用AJAX时，加上async: true即可

JAVA中远程请求使用Feign

1. 首先定义接口RemoteJgProxyPoolService

@FeignClient(name = ProxyPoolConstants.JG_NAME,url = ProxyPoolConstants.JG_URL,configuration = OkhttpConfig.class,fallbackFactory = RemoteJgProxyPoolFallbackFactory.class)
public interface RemoteJgProxyPoolService {

	/**
	 * getProxy
	 */
	@GetMapping()
	String getProxy();
}

2. 在定义实现接口的类
@Slf4j
@Component
public class RemoteProxyPoolFallbackImpl implements RemoteProxyPoolService {
    @Setter
    private Throwable cause;
    
	@Override
	public String getProxy() {
		log.error("获取代理IP池{}失败", cause.getMessage());
		return null;
	}
}

3. 注入到bean容器中
@Component
public class RemoteJgProxyPoolFallbackFactory implements FallbackFactory<RemoteJgProxyPoolService> {

	@Override
	public RemoteJgProxyPoolService create(Throwable throwable) {
		RemoteJgProxyPoolFallbackImpl remoteJgProxyPoolFallback = new RemoteJgProxyPoolFallbackImpl();
		remoteJgProxyPoolFallback.setCause(throwable);
		return remoteJgProxyPoolFallback;
	}
}

4. 然后就可以使用了
@Resource
private final RemoteJgProxyPoolService remoteJgProxyPoolService;