WebSocket的初次使用及调试

出现的错误
1
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.3:compile (default-compile) on project JavaWebSocket: Fatal error compiling: 无效的目标发行版: 1.8 -> [Help 1]
修改：


   <plugin>
    <artifactId>maven-war-plugin</artifactId>
    <version>2.6</version>
    <configuration>
      <warSourceDirectory>WebRoot</warSourceDirectory>
      <failOnMissingWebXml>false</failOnMissingWebXml>
    </configuration>
  </plugin>
  <plugin>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>3.3</version>
    <configuration>
      <source>1.8</source>
      <target>1.8</target>
    </configuration>
  </plugin>
<plugins>
  <plugin>
    <artifactId>maven-war-plugin</artifactId>
  </plugin>
  <plugin>
    <artifactId>maven-compiler-plugin</artifactId>
    <configuration>
      <source>1.6</source>
      <target>1.6</target>
    </configuration>
  </plugin>
</plugins>

此处使用maven自动打包上传的插件

4.0.0 WeeeebSkt WeeeebSkt 0.0.1-SNAPSHOT war

[INFO] Deploying war to http://localhost:8080/WeeeebSkt [INFO] OK - Deployed application at context path /WeeeebSkt [INFO] ———————————————————————— [INFO] BUILD SUCCESS [INFO] ———————————————————————— [INFO] Total time: 2.045 s [INFO] Finished at: 2017-11-13T13:29:02+08:00 [INFO] Final Memory: 15M/308M [INFO] ————————————————————————

(index):20 WebSocket connection to 'ws://localhost:8080/websocket' failed: Error during WebSocket handshake: Unexpected response code: 404

if (‘WebSocket’ in window) { //websocket = new WebSocket(“ws://localhost:8080/websocket”); websocket = new WebSocket(“ws://localhost:8080/websocket”); }

WebSocket connection to ‘ws://localhost:8080/WeeeebSkt/websocket’ failed: Error during WebSocket handshake: Unexpected response code: 404

if (‘WebSocket’ in window) { //websocket = new WebSocket(“ws://localhost:8080/websocket”); websocket = new WebSocket(“ws://localhost:8080/websocket”); }

[CodeLive] HTTP detected: Connecting using WS VM37:109 [CodeLive] Connected to CodeLive at ws://127.0.0.1:8123

import java.io.IOException; import java.util.concurrent.CopyOnWriteArraySet; import javax.websocket.*; import javax.websocket.server.ServerEndpoint;

/**

• @ServerEndpoint 注解是一个类层次的注解，它的功能主要是将目前的类定义成一个websocket服务器端,
• 注解的值将被用于监听用户连接的终端访问URL地址,客户端可以通过这个URL来连接到WebSocket服务器端 */ @ServerEndpoint(“/websocket”) public class Ws { //静态变量，用来记录当前在线连接数。应该把它设计成线程安全的。 private static int onlineCount = 0; //concurrent包的线程安全Set，用来存放每个客户端对应的MyWebSocket对象。若要实现服务端与单一客户端通信的话，可以使用Map来存放，其中Key可以为用户标识 private static CopyOnWriteArraySet webSocketSet = new CopyOnWriteArraySet(); //与某个客户端的连接会话，需要通过它来给客户端发送数据 private Session session; /**
  • 连接建立成功调用的方法
  • @param session 可选的参数。session为与某个客户端的连接会话，需要通过它来给客户端发送数据 */ @OnOpen public void onOpen(Session session){ this.session = session; webSocketSet.add(this); //加入set中 addOnlineCount(); //在线数加1 System.out.println(“有新连接加入！当前在线人数为” + getOnlineCount()); } /**
  • 连接关闭调用的方法 */ @OnClose public void onClose(){ webSocketSet.remove(this); //从set中删除 subOnlineCount(); //在线数减1 System.out.println(“有一连接关闭！当前在线人数为” + getOnlineCount()); } /**
  • 收到客户端消息后调用的方法
  • @param message 客户端发送过来的消息
  • @param session 可选的参数 */ @OnMessage public void onMessage(String message, Session session) { System.out.println(“来自客户端的消息:” + message); //群发消息 for(Ws item: webSocketSet){ try { item.sendMessage(message); } catch (IOException e) { e.printStackTrace(); continue; } } } /**
  • 发生错误时调用
  • @param session
  • @param error */ @OnError public void onError(Session session, Throwable error){ System.out.println(“发生错误”); error.printStackTrace(); } }

4.0.0 JavaWebSocket JavaWebSocket 0.0.1-SNAPSHOT war 3.1

javax.websocket javax.websocket-api 1.0 src maven-compiler-plugin 3.3 1.8 1.8 org.codehaus.mojo tomcat-maven-plugin 1.1 http://localhost:9080/manager/text tomcat8 admin admin true

  <plugin>
    <artifactId>maven-war-plugin</artifactId>
    <version>2.6</version>
    <configuration>
      <warSourceDirectory>WebRoot</warSourceDirectory>
      <failOnMissingWebXml>false</failOnMissingWebXml>
    </configuration>
  </plugin>
</plugins>

```