Spring Websocket No suitable def

前言

现在主流的web容器基本均已支持websocket，但各容器的websocket接口都不尽相同。为了统一websocket实现，便于今后在不同web容器间的移植，这里使用spring websocket框架集成。

spring依赖

添加spring所需依赖

<spring.framework.version>4.2.1.RELEASE</spring.framework.version>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>${spring.framework.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
<version>${spring.framework.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${spring.framework.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>
<version>${spring.framework.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>${spring.framework.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-expression</artifactId>
<version>${spring.framework.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aspects</artifactId>
<version>${spring.framework.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${spring.framework.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-websocket</artifactId>
<version>${spring.framework.version}</version>
</dependency>

websocket依赖

对于jetty，添加如下依赖

<dependency>
    <groupId>org.eclipse.jetty.websocket</groupId>
    <artifactId>websocket-server</artifactId>
    <version>9.3.3.v20150827</version>
    <scope>provided</scope>
</dependency>

对于tomcat，添加如下依赖

<dependency>
    <groupId>org.apache.tomcat.embed</groupId>
    <artifactId>tomcat-embed-websocket</artifactId>
    <version>8.0.23</version>
    <scope>provided</scope>
</dependency>

对于上述jetty或者tomcat依赖，需要注意依赖版本与容器版本的兼容性，另一方面需要注意将依赖的scope设置为provided

添加Handler

添加HandshakeInterceptor

/**

• <pre>

• 豆瓣电台websocket握手接口实现

• </pre>

• @author ManerFan 2015年9月7日
  */
  @Component
  public class DoubanFMHandshakeInterceptor extends HttpSessionHandshakeInterceptor {

  @Override
  public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse response,
  WebSocketHandler wsHandler, Map<String, Object> attributes) throws Exception {
  // 握手前的处理逻辑
  return super.beforeHandshake(request, response, wsHandler, attributes);
  }

  @Override
  public void afterHandshake(ServerHttpRequest request, ServerHttpResponse response,
  WebSocketHandler wsHandler, Exception ex) {
  // 握手后的处理逻辑
  super.afterHandshake(request, response, wsHandler, ex);
  }

}spring提供了多种HandshakeInterceptor实现，可以根据实际需要在其基础上实现自己的逻辑。当然，也可以直接使用spring的默认HandshakeInterceptor

添加WebSocketHandler

/**

• <pre>

• 豆瓣FM websocket消息处理

• </pre>

• @author ManerFan 2015年9月7日
  */
  @Component
  public class DoubanFMWebSocketHandler extends TextWebSocketHandler {

  /**

  • logger
    */
    private static final Logger LOGGER = CommonLogger.getLogger();

  /**

  • 记录连接上的所有session
    */
    private Map<String, WebSocketSession> sessionMap = Collections
    .synchronizedMap(new HashMap<String, WebSocketSession>());

  @Override
  public void afterConnectionEstablished(WebSocketSession session) throws Exception {
  // 建立连接之后
  LOGGER.info("[{}:{}] has bean connected", session.getUri(), session.getId());
  sessionMap.put(session.getId(), session);
  }

  @Override
  protected void handleTextMessage(WebSocketSession session, TextMessage message)
  throws Exception {
  // 收到消息之后
  String payload = message.getPayload();
  Signalling signalling = JacksonUtils.instance().readValue(payload, TYPE_REFERENCE);
  if (null == signalling) {
  LOGGER.warn("Receive an Empty Payload [?][{}] from [{}:{}].", payload, session.getUri(),
  session.getId());
  return;
  }

   switch (signalling.getSignal()) {
       case C_START: /* 播放某一频道 */
           doStart(session, signalling.getMessage());
           break;
       case C_STOP: /* 停止收听 */
           doStop();
           break;
       case C_SKIP: /* 跳过该首 */
           doSkip(signalling.getMessage());
           break;
       case C_RATE: /* 喜欢 */
           doRate(signalling.getMessage());
           break;
       case C_UNRATE: /* 取消喜欢 */
           doUnRate(signalling.getMessage());
           break;
       case C_BYE: /* 不再收听 */
           doBye(signalling.getMessage());
           break;
       default:
           break;
   }
  

  }

  @Override
  public void afterConnectionClosed(WebSocketSession session, CloseStatus status)
  throws Exception {
  // 连接断开之后
  LOGGER.info("[{}:{}] has bean closed", session.getUri(), session.getId());
  sessionMap.remove(session.getId());

   if (sessionMap.isEmpty()) {
       /* 没有客户端在线了 */
       doStop();
   }
  

  }
  }

spring同样提供了TextWebSocketHandler BinaryWebSocketHandler等多种WebSocketHandler，可根据实际需要进行选择

初始化websocket

websocket的初始化，可以使用配置方式，也可以使用注解方式，关于spring websocket的使用及配置，详见websocket-doc，这里记录注解方式初始化方法

/**

• <pre>

• WebSocket初始化配置

• <a href="http://docs.spring.io/spring/docs/current/spring-framework-reference/html/websocket.html">DOC for Spring Websocket</a>

• </pre>

• @author ManerFan 2015年9月7日
  */
  @Configuration
  @EnableWebMvc
  @EnableWebSocket
  public class WebSocketConfig extends WebMvcConfigurerAdapter implements WebSocketConfigurer {

  /**

  • <beans xmlns="http://www.springframework.org/schema/beans"

  •  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
    

  •  xmlns:websocket="http://www.springframework.org/schema/websocket"  
    

  •  xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd  
    

  •  http://www.springframework.org/schema/websocket http://www.springframework.org/schema/websocket/spring-websocket.xsd">
    

  •  <bean id="handler" class="com.manerfan.webapp.controller.douban.fm.websockt.FMWebSocketHandler"/>  
    

  •  <websocket:handlers>  
    

  •     <websocket:mapping path="/websocket/doubanfm" handler="handler"/>  
    

  •     <websocket:handshake-interceptors>  
    

  •         <bean class="com.manerfan.webapp.controller.douban.fm.websock.FMHandshakeInterceptor"/>  
    

  •     </websocket:handshake-interceptors> 
    

  •     <!-- <websocket:sockjs/> --> 
    

  •  </websocket:handlers>
    

  • </beans>
    */

  /** Douban FM */
  @Autowired
  private DoubanFMWebSocketHandler doubanFmWebSocketHandler;
  @Autowired
  private DoubanFMHandshakeInterceptor doubanFMHandshakeInterceptor;

  @Override
  public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
  /** Douban FM /
  registry.addHandler(doubanFmWebSocketHandler, "/websocket/doubanfm").addInterceptors(
  doubanFMHandshakeInterceptor).setAllowedOrigins("")/不加AllowedOrigins，有可能会全拒绝/;
  /registry.addHandler(doubanFmWebSocketHandler, "/sockjs/doubanfm")
  .addInterceptors(doubanFMHandshakeInterceptor).withSockJS();/ /用于支持SockJS/
  }

  /**

  • Each underlying WebSocket engine exposes configuration properties
  • that control runtime characteristics such as the size of message buffer sizes,
  • idle timeout, and others.
    */

  /**

  • For Tomcat, WildFly, and GlassFish add a ServletServerContainerFactoryBean
  • to your WebSocket Java config:
    /
    /@Bean
    public ServletServerContainerFactoryBean createWebSocketContainer() {
    ServletServerContainerFactoryBean container = new ServletServerContainerFactoryBean();
    container.setMaxTextMessageBufferSize(8192);
    container.setMaxBinaryMessageBufferSize(8192);
    return container;
    }*/

  /**

  • For Jetty, you’ll need to supply a pre-configured Jetty WebSocketServerFactory

  • and plug that into Spring’s DefaultHandshakeHandler through your WebSocket Java config:
    */
    @Bean
    public DefaultHandshakeHandler handshakeHandler() {

    WebSocketPolicy policy = new WebSocketPolicy(WebSocketBehavior.SERVER);
    policy.setInputBufferSize(8192); /* 设置消息缓冲大小 /
    policy.setIdleTimeout(600000); / 10分钟read不到数据的话，则断开该客户端 */

    return new DefaultHandshakeHandler(
    new JettyRequestUpgradeStrategy(new WebSocketServerFactory(policy)));
    }

}

setAllowedOrigins用于约束允许建立连接的客户端
withSockJS用于提供SockJS支持

至此，websocket后台框架便搭建完成
javascript可使用如下方式与后台建立连接进行通信

/* 建立连接 /
var ws = new WebSocket("ws://localhost/rasp/websocket/doubanfm");
ws.onopen = function() { / 连接成功时 /
ws.send(JSON.stringify({signal:'C_START', message:'179'}));
};
ws.onmessage = function (evt){ / 收到消息时 /
var received_msg = evt.data;
console.info("Message is received... " + received_msg);
};
ws.onclose = function() { / 连接断开时 /
console.warn("Connection is closed...");
};
ws.onerror = function(e) { / 出现错误时 */
console.error(e);
}

开发时遇到的异常及解决办法
•No suitable default RequestUpgradeStrategy found

严重: Context initialization failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name ‘webSocketHandlerMapping’ defined in class path resource [org/springframework/web/socket/config/annotation/DelegatingWebSocketConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.web.servlet.HandlerMapping]: Factory method ‘webSocketHandlerMapping’ threw exception; nested exception is java.lang.IllegalStateException: No suitable default RequestUpgradeStrategy found
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:599)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1111)
at …
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.web.servlet.HandlerMapping]: Factory method ‘webSocketHandlerMapping’ threw exception; nested exception is java.lang.IllegalStateException: No suitable default RequestUpgradeStrategy found
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:189)
at …
Caused by: java.lang.IllegalStateException: No suitable default RequestUpgradeStrategy found
at org.springframework.web.socket.server.support.DefaultHandshakeHandler.initRequestUpgradeStrategy(DefaultHandshakeHandler.java:127)
at …

出现上述异常，是由于缺少RequestUpgradeStrategy
对于jetty，需要添加如下依赖

<dependency>
    <groupId>org.eclipse.jetty.websocket</groupId>
    <artifactId>websocket-server</artifactId>
    <version>9.3.3.v20150827</version>
    <scope>provided</scope>
</dependency>

对于tomcat，需要添加如下依赖

<dependency>
    <groupId>org.apache.tomcat.embed</groupId>
    <artifactId>tomcat-embed-websocket</artifactId>
    <version>8.0.23</version>
    <scope>provided</scope>
</dependency>

•java.lang.ClassCastException: org.eclipse.jetty.server.HttpConnection cannot be cast to org.eclipse.jetty.server.HttpConnection

页面报如下异常

WebSocket connection to ‘ws://localhost/rasp/websocket/doubanfm’ failed: Error during WebSocket handshake: Unexpected response code: 500

后台报如下异常

WARN:oejs.ServletHandler:qtp1237514926-20:
org.springframework.web.util.NestedServletException: Request processing failed; nested exception is org.springframework.web.socket.server.HandshakeFailureException: Uncaught failure for request http://localhost:80/rasp/websocket/doubanfm; nested exception is java.lang.ClassCastException: org.eclipse.jetty.server.HttpConnection cannot be cast to org.eclipse.jetty.server.HttpConnection
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:978)
at …
Caused by:
org.springframework.web.socket.server.HandshakeFailureException: Uncaught failure for request http://localhost:80/rasp/websocket/doubanfm; nested exception is java.lang.ClassCastException: org.eclipse.jetty.server.HttpConnection cannot be cast to org.eclipse.jetty.server.HttpConnection
at org.springframework.web.socket.server.support.WebSocketHttpRequestHandler.handleRequest(WebSocketHttpRequestHandler.java:135)
at …
Caused by:
java.lang.ClassCastException: org.eclipse.jetty.server.HttpConnection cannot be cast to org.eclipse.jetty.server.HttpConnection
at org.eclipse.jetty.websocket.server.WebSocketServerFactory.acceptWebSocket(WebSocketServerFactory.java:182)
at …

出现此情况，一般是由于工程中引用的javax.servlet与web容器相关jar包冲突导致
将javax.servlet相关依赖scope置为provided即可

<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>servlet-api</artifactId>
    <scope>provided</scope><!-- 只在编译的时候 -->
</dependency>

•Unexpected response code: 403

页面报此异常，一般是由于websocket拒绝了此链接请求
在websocket初始化时，将setAllowedOrigins加上即可