Spring Boot 2.2 原生注解简易集成 websocket

朴灿烈づ我的快乐病毒、 2023-07-16 11:59 9阅读 0赞

### 文章目录 ###

*   *   *  1 摘要
         *  2 核心 Maven 依赖
         *  3 配置信息
         *  4 核心代码类
         *   *  4.1 websocket 配置类
             *  4.2 websocket 消息体封装类
             *  4.3 socket 消息编码类
             *  4.4 socket 消息解码类
             *  4.5 websocket 服务端站点类
             *  4.6 SpringBoot 启动类
         *  5 测试
         *  6 参考资料推荐
         *  7 Github 源码

### 1 摘要 ###

Websocket 是一种基于 TCP 连接的可进行双工通讯的协议，能够更好地方便客户端与服务端数据传输，允许服务端向客户端主动发送消息。相较于 HTTP 连接， websocket 不需要3次握手，1次握手之后即可实现服务端与客户端的数据通讯。Websocket 通常用于实时聊天通讯场景，本文将介绍在 SpringBoot 中使用**原生注解**简易集成 websocket。

### 2 核心 Maven 依赖 ###

./demo-websocket/pom.xml

<dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-websocket</artifactId>
            </dependency>

其中 `springboot` 的版本为 `2.2.5.RELEASE`

### 3 配置信息 ###

./demo-websocket/src/main/resources/application.yml

## config
    
    ## server
    server:
      port: 8200

`websocket` 的端口即为服务端口,若不自定义,则默认为 `8080` 端口

### 4 核心代码类 ###

#### 4.1 websocket 配置类 ####

./demo-websocket/src/main/java/com/ljq/demo/springboot/websocket/common/config/WebsocketConfig.java

package com.ljq.demo.springboot.websocket.common.config;
    
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.web.socket.config.annotation.EnableWebSocket;
    import org.springframework.web.socket.server.standard.ServerEndpointExporter;
    
    /** * @Description: websocket 配置信息 * @Author: junqiang.lu * @Date: 2020/3/14 */
    @Configuration
    @EnableWebSocket
    public class WebsocketConfig { 
    
        @Bean
        public ServerEndpointExporter serverEndpointExporter() { 
            return new ServerEndpointExporter();
        }
    }

#### 4.2 websocket 消息体封装类 ####

./demo-websocket/src/main/java/com/ljq/demo/springboot/websocket/model/entity/SocketMessage.java

package com.ljq.demo.springboot.websocket.model.entity;
    
    import lombok.Data;
    
    /** * @Description: 聊天信息封装类 * @Author: junqiang.lu * @Date: 2020/3/14 */
    @Data
    public class SocketMessage { 
    
        /** * 消息发送者 */
        private String from;
        /** * 消息接收者 */
        private String to;
        /** * 消息内容 */
        private String content;
    }

#### 4.3 socket 消息编码类 ####

./demo-websocket/src/main/java/com/ljq/demo/springboot/websocket/common/util/SocketEncoder.java

package com.ljq.demo.springboot.websocket.common.util;
    
    import com.fasterxml.jackson.core.JsonProcessingException;
    import com.fasterxml.jackson.databind.ObjectMapper;
    import com.ljq.demo.springboot.websocket.model.entity.SocketMessage;
    
    import javax.websocket.EncodeException;
    import javax.websocket.Encoder;
    import javax.websocket.EndpointConfig;
    
    /** * @Description: socket 消息编码器 * @Author: junqiang.lu * @Date: 2020/3/14 */
    public class SocketEncoder implements Encoder.Text<SocketMessage> { 
    
        private static ObjectMapper objectMapper = new ObjectMapper();
    
        @Override
        public String encode(SocketMessage socketMessage) throws EncodeException { 
            try { 
                return objectMapper.writeValueAsString(socketMessage);
            } catch (JsonProcessingException e) { 
                e.printStackTrace();
            }
            return null;
        }
    
        @Override
        public void init(EndpointConfig endpointConfig) { 
    
        }
    
        @Override
        public void destroy() { 
    
        }
    }

#### 4.4 socket 消息解码类 ####

./demo-websocket/src/main/java/com/ljq/demo/springboot/websocket/common/util/SocketDecoder.java

package com.ljq.demo.springboot.websocket.common.util;
    
    import com.fasterxml.jackson.core.JsonProcessingException;
    import com.fasterxml.jackson.databind.ObjectMapper;
    import com.ljq.demo.springboot.websocket.model.entity.SocketMessage;
    
    import javax.websocket.DecodeException;
    import javax.websocket.Decoder;
    import javax.websocket.EndpointConfig;
    
    /** * @Description: websocket 消息解码器 * @Author: junqiang.lu * @Date: 2020/3/14 */
    public class SocketDecoder implements Decoder.Text<SocketMessage> { 
    
        private static ObjectMapper objectMapper = new ObjectMapper();
    
        @Override
        public SocketMessage decode(String s) throws DecodeException { 
    
            try { 
                return objectMapper.readValue(s, SocketMessage.class);
            } catch (JsonProcessingException e) { 
                e.printStackTrace();
            }
            return null;
        }
    
        @Override
        public boolean willDecode(String s) { 
            return (s != null);
        }
    
        @Override
        public void init(EndpointConfig endpointConfig) { 
    
        }
    
        @Override
        public void destroy() { 
    
        }
    }

#### 4.5 websocket 服务端站点类 ####

./demo-websocket/src/main/java/com/ljq/demo/springboot/websocket/web/ChatEndPoint.java

package com.ljq.demo.springboot.websocket.web;
    
    import com.ljq.demo.springboot.websocket.common.util.SocketDecoder;
    import com.ljq.demo.springboot.websocket.common.util.SocketEncoder;
    import com.ljq.demo.springboot.websocket.model.entity.SocketMessage;
    import lombok.extern.slf4j.Slf4j;
    import org.springframework.stereotype.Component;
    
    import javax.websocket.*;
    import javax.websocket.server.PathParam;
    import javax.websocket.server.ServerEndpoint;
    import java.io.IOException;
    import java.util.HashMap;
    import java.util.Map;
    import java.util.Set;
    import java.util.concurrent.CopyOnWriteArraySet;
    
    /** * @Description: websocket 服务端站点 * @Author: junqiang.lu * @Date: 2020/3/14 */
    @Slf4j
    @Component
    @ServerEndpoint(value = "/chat/{username}", encoders = { SocketEncoder.class}, decoders = { SocketDecoder.class})
    public class ChatEndPoint { 
    
        private Session session;
    
        private static Set<ChatEndPoint> chatEndPoints = new CopyOnWriteArraySet<>();
    
        private static Map<String, String> users = new HashMap<>();
    
        /** * 打开 socket 连接 * * @param session * @param username */
        @OnOpen
        public void onOpen(Session session, @PathParam("username") String username) { 
            log.debug("Websocket is opening ");
    
            this.session = session;
            chatEndPoints.add(this);
            users.put(session.getId(), username);
            log.debug("username: {}", username);
    
            SocketMessage message = new SocketMessage();
            message.setFrom(username);
            message.setContent("Connected !!!, online user: " + users.size());
            broadcast(message);
            log.debug("online user: {}", users.size());
        }
    
        /** * 发送信息 * * @param session * @param message */
        @OnMessage
        public void onMessage(Session session, SocketMessage message) { 
            message.setFrom(users.getOrDefault(session.getId(), ""));
            log.debug("message: {}", message.toString());
    
            broadcast(message);
            log.debug("online user: {}", users.size());
        }
    
        /** * 关闭 socket 连接 * * @param session */
        @OnClose
        public void onClose(Session session) { 
            log.debug("Socket is closing .");
            log.debug("username: {}", users.getOrDefault(session.getId(), ""));
    
            chatEndPoints.remove(this);
            users.remove(session.getId());
    
            SocketMessage message = new SocketMessage();
            message.setFrom(users.getOrDefault(session.getId(), ""));
            message.setContent("Socket disconnected .");
            broadcast(message);
            log.debug("online user: {}", users.size());
        }
    
        /** * 异常 * * @param session */
        @OnError
        public void onError(Session session, Throwable throwable) { 
            log.error("Socket exception", throwable);
            log.debug("online user: {}", users.size());
        }
    
        /** * 信息发送 * * @param message */
        private static void broadcast(SocketMessage message) { 
            chatEndPoints.forEach(chatEndPoint -> { 
                synchronized (chatEndPoint) { 
                    try { 
                        chatEndPoint.session.getBasicRemote().sendObject(message);
                    } catch (IOException e) { 
                        e.printStackTrace();
                    } catch (EncodeException e) { 
                        e.printStackTrace();
                    }
                }
            });
        }
    }

`websocket` 注解说明:

`@ServerEndpoint` : websocket 服务端站点注解，用于Java类，类似于 `@Controller`, 使用该注解的类，即可接收客户端发来的 socket 信息

`@OnOpen`: 该注解用于方法上，打开 socket 连接时触发

`@OnMessage`: 该注解用于方法上，在客户端发送消息时触发

`@OnClose`: 该注解用于方法上,当关闭 socket 连接时触发

`@OnError`: 该注解用于方法上,当 socket 连接出现异常时触发，触发异常，会导致 socket 连接断开。通常发送的消息不合法、格式错误会导致异常抛出。

#### 4.6 SpringBoot 启动类 ####

./demo-websocket/src/main/java/com/ljq/demo/springboot/websocket/DemoWebsocketApplication.java

package com.ljq.demo.springboot.websocket;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    
    /** * @Description: websocket SpringBoot 启动类 * @Author: junqiang.lu * @Date: 2020/3/14 */
    @SpringBootApplication
    public class DemoWebsocketApplication { 
    
        public static void main(String[] args) { 
            SpringApplication.run(DemoWebsocketApplication.class, args);
        }
    
    }

### 5 测试 ###

在线 websocket 测试地址:

[WebSocket在线测试工具][WebSocket]

[在线WebSocket测试工具][WebSocket 1]

启动项目,在测试网站输入 websocket 地址:

ws://127.0.0.1:8200/chat/demo1

`127.0.0.1` 为本机 ip 地址，可根据需要自行更改 ip 地址

`demo1` 为用户名,测试时可自行更换

连接成功，返回的结果为:

{ 
        "from": "demo1",
        "to": null,
        "content": "Connected !!!, online user: 1"
    }

控制台日志:

发送消息,消息内容:

{ 
        "to": "demo2",
        "content": "Hello"
    }

返回结果:

{ 
        "from": "demo1",
        "to": "demo2",
        "content": "Hello"
    }

控制台日志:

断开连接，控制台日志:

以上为单个用户的测试，可以使用多个设备登录测试网站进行 websocket 连接测试

### 6 参考资料推荐 ###

[A Guide to the Java API for WebSocket][]

[Spring Boot系列十六 WebSocket简介和spring boot集成简单消息代理][Spring Boot_ WebSocket_spring boot]

[【websocket】spring boot 集成 websocket 的四种方式][websocket_spring boot _ websocket]

[WebSocket在线测试工具][WebSocket]

[在线WebSocket测试工具][WebSocket 1]

### 7 Github 源码 ###

**Gtihub 源码地址** : [https://github.com/Flying9001/springBootDemo][https_github.com_Flying9001_springBootDemo]

个人公众号:**404Code**,分享半个互联网人的技术与思考，感兴趣的可以关注.  
![404Code][]

[WebSocket]: http://ws.douqq.com
[WebSocket 1]: http://www.toolnb.com/tools/webSocketTools.html
[A Guide to the Java API for WebSocket]: https://www.baeldung.com/java-websockets
[Spring Boot_ WebSocket_spring boot]: https://blog.csdn.net/hry2015/article/details/79829616
[websocket_spring boot _ websocket]: https://juejin.im/post/5db05df76fb9a0206062b6d4
[https_github.com_Flying9001_springBootDemo]: https://github.com/Flying9001/springBootDemo
[404Code]: /images/20230528/10275f856ec34434b8bbe7247fb3c4ac.png