1.引入websocket依赖
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-websocket</artifactId>
<scope>provided</scope>
</dependency>
2.添加配置文件WebSocketConfig.class
@Configuration
public class WebSocketConfig {
@Bean
public ServerEndpointExporter serverEndpointExporter() {
return new ServerEndpointExporter();
}
}
3.实现消息通知类WebSocketServer.class
@Component
@ServerEndpoint(value = "/websocket/{id}")
public class WebSocketServer {
private static int onlineCount = 0;
private static ConcurrentHashMap<String, WebSocketServer> webSocketMap = new ConcurrentHashMap<>();
//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;
private static Logger log = LogManager.getLogger(WebSocketServer.class);
private String id = "";
/**
* 连接建立成功调用的方法
* @param id 用户的标识
* @param session 会话
*/
@OnOpen
public void onOpen(@PathParam(value = "id") String id, Session session) {
//设置超时时间
session.setMaxIdleTimeout(3600000);
this.session = session;
//接收到发送消息的人员编号
this.id = id;
//加入set中
if (webSocketMap.containsKey(id)){
webSocketMap.remove(id);
}
webSocketMap.put(id, this);
//在线数加1
addOnlineCount();
log.info("用户"+id+"加入!当前在线人数为" + getOnlineCount());
try {
sendMessage("连接成功");
} catch (IOException e) {
log.error("websocket IO异常");
}
}
/**
* 连接关闭调用的方法
*/
@OnClose
public void onClose() {
//从map中删除
webSocketMap.remove(this.id);
//在线数减1
subOnlineCount();
log.info("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 会话
* */
@OnMessage
public void onMessage(String message, Session session) {
log.info("来自客户端的消息:" + message);
//可以自己约定字符串内容,比如 内容|0 表示信息群发,内容|X 表示信息发给id为X的用户
String sendMessage = message.split("[|]")[0];
String sendUserId = message.split("[|]")[1];
try {
if(sendUserId.equals("0")) {
sendtoAll(sendMessage);
}
else {
sendMessageTo(sendMessage, sendUserId);
}
} catch (IOException e) {
e.printStackTrace();
}
}
/**
*
* @param session
* @param error
*/
@OnError
public void onError(Session session, Throwable error) {
log.error("发生错误");
error.printStackTrace();
}
public void sendMessage(String message) throws IOException {
this.session.getBasicRemote().sendText(message);
}
public void sendMessageTo(String message,String sendUserId) throws IOException{
if (webSocketMap.get(sendUserId) != null) {
if(!id.equals(sendUserId)){
webSocketMap.get(sendUserId).sendMessage( "用户" + id + "发来消息:" + " <br/> " + message);
}
else {
webSocketMap.get(sendUserId).sendMessage(message);
}
} else {
//如果用户不在线则返回不在线信息给自己
// sendtoUser("当前用户不在线",id);
}
}
/**
* 发送信息给所有人
* @param message
* @throws IOException
*/
public void sendtoAll(String message) throws IOException {
for (String key : webSocketMap.keySet()) {
try {
webSocketMap.get(key).sendMessage(message);
} catch (IOException e) {
e.printStackTrace();
}
}
}
public static synchronized int getOnlineCount() {
return onlineCount;
}
public static synchronized void addOnlineCount() {
WebSocketServer.onlineCount++;
}
public static synchronized void subOnlineCount() {
WebSocketServer.onlineCount--;
}
}
4.测试
前端js访问http://localhost:8080/websocket/123