websocket最偉大之處在於服務器和客戶端可以在給定的時間範圍內的任意時刻,相互推送信息。 瀏覽器和服務器只需要要做一個握手的動作,在建立連接之後,服務器可以主動傳送數據給客戶端,客戶端也可以隨時向服務器發送數據。
實現功能:springboot整合websocket實現一對一,多對多聊天系統。
依賴
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.28</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-websocket</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
配置類WebSocketConfig
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;
@Configuration
public class WebSocketConfig {
/**
* 服務器節點
* 如果使用獨立的servlet容器,而不是直接使用springboot的內置容器,就不要注入ServerEndpointExporter,因爲它將由容器自己提供和管理
*/
@Bean
public ServerEndpointExporter serverEndpointExporter() {
return new ServerEndpointExporter();
}
}
WebSocket
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
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.ConcurrentHashMap;
@Slf4j
@Component
@ServerEndpoint("/websocket/{username}")
public class WebSocket {
/**
* 在線人數
*/
public static int onlineNumber = 0;
/**
* 以用戶的姓名爲key,WebSocket爲對象保存起來
*/
private static Map<String, WebSocket> clients = new ConcurrentHashMap<String, WebSocket>();
/**
* 會話
*/
private Session session;
/**
* 用戶名稱
*/
private String username;
/**
* OnOpen 表示有瀏覽器鏈接過來的時候被調用
* OnClose 表示瀏覽器發出關閉請求的時候被調用
* OnMessage 表示瀏覽器發消息的時候被調用
* OnError 表示有錯誤發生,比如網絡斷開了等等
*/
/**
* 建立連接
*
* @param session
*/
@OnOpen
public void onOpen(@PathParam("username") String username, Session session) {
onlineNumber++;
log.info("現在來連接的客戶id:" + session.getId() + "用戶名:" + username);
this.username = username;
this.session = session;
log.info("有新連接加入! 當前在線人數" + onlineNumber);
try {
//messageType 1代表上線 2代表下線 3代表在線名單 4代表普通消息
//先給所有人發送通知,說我上線了
Map<String, Object> map1 = new HashMap<>();
map1.put("messageType", 1);
map1.put("username", username);
sendMessageAll(JSON.toJSONString(map1), username);
//把自己的信息加入到map當中去
clients.put(username, this);
//給自己發一條消息:告訴自己現在都有誰在線
Map<String, Object> map2 = new HashMap<>();
map2.put("messageType", 3);
//移除掉自己
Set<String> set = clients.keySet();
map2.put("onlineUsers", set);
sendMessageTo(JSON.toJSONString(map2), username);
} catch (IOException e) {
log.info(username + "上線的時候通知所有人發生了錯誤");
}
}
@OnError
public void onError(Session session, Throwable error) {
log.info("服務端發生了錯誤" + error.getMessage());
//error.printStackTrace();
}
/**
* 連接關閉
*/
@OnClose
public void onClose() {
onlineNumber--;
//webSockets.remove(this);
clients.remove(username);
try {
//messageType 1代表上線 2代表下線 3代表在線名單 4代表普通消息
Map<String, Object> map1 = new HashMap<>();
map1.put("messageType", 2);
map1.put("onlineUsers", clients.keySet());
map1.put("username", username);
sendMessageAll(JSON.toJSONString(map1), username);
} catch (IOException e) {
log.info(username + "下線的時候通知所有人發生了錯誤");
}
log.info("有連接關閉! 當前在線人數" + onlineNumber);
}
/**
* 收到客戶端的消息
*
* @param message 消息
* @param session 會話
*/
@OnMessage
public void onMessage(String message, Session session) {
try {
log.info("來自客戶端消息:" + message + "客戶端的id是:" + session.getId());
JSONObject jsonObject = JSON.parseObject(message);
String textMessage = jsonObject.getString("message");
String fromusername = jsonObject.getString("username");
String tousername = jsonObject.getString("to");
//如果不是發給所有,那麼就發給某一個人
//messageType 1代表上線 2代表下線 3代表在線名單 4代表普通消息
Map<String, Object> map1 = new HashMap<>();
map1.put("messageType", 4);
map1.put("textMessage", textMessage);
map1.put("fromusername", fromusername);
if (tousername.equals("All")) {
map1.put("tousername", "所有人");
sendMessageAll(JSON.toJSONString(map1), fromusername);
} else {
map1.put("tousername", tousername);
sendMessageTo(JSON.toJSONString(map1), tousername);
}
} catch (Exception e) {
log.info("發生了錯誤了");
}
}
public void sendMessageTo(String message, String ToUserName) throws IOException {
for (WebSocket item : clients.values()) {
if (item.username.equals(ToUserName)) {
item.session.getAsyncRemote().sendText(message);
break;
}
}
}
public void sendMessageAll(String message, String FromUserName) throws IOException {
for (WebSocket item : clients.values()) {
item.session.getAsyncRemote().sendText(message);
}
}
public static synchronized int getOnlineCount() {
return onlineNumber;
}
}
WebSocketController
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
@Slf4j
@Controller
public class WebSocketController {
@RequestMapping("/websocket/{name}")
public String webSocket(@PathVariable String name, Model model) {
try {
log.info("跳轉到websocket的頁面上");
model.addAttribute("username", name);
return "websocket";
} catch (Exception e) {
log.info("跳轉到websocket的頁面上發生異常,異常信息是:" + e.getMessage());
return "error";
}
}
}
websocket.html(位置:templates文件夾下)
<!DOCTYPE html>
<html xmlns:th="http://www.w3.org/1999/xhtml">
<head>
<title>websocket</title>
<script type="text/javascript" src="http://ajax.microsoft.com/ajax/jquery/jquery-1.4.min.js"></script>
<script src="http://cdn.bootcss.com/stomp.js/2.3.3/stomp.min.js"></script>
<script src="https://cdn.bootcss.com/sockjs-client/1.1.4/sockjs.min.js"></script>
</head>
<body>
<div style="margin: auto;text-align: center">
<h1>Welcome to websocket</h1>
</div>
<br/>
<div style="margin: auto;text-align: center">
<select id="onLineUser">
<option>--所有--</option>
</select>
<input id="text" type="text"/>
<button onclick="send()">發送消息</button>
</div>
<br>
<div style="margin-right: 10px;text-align: right">
<button onclick="closeWebSocket()">關閉連接</button>
</div>
<hr/>
<div id="message" style="text-align: center;"></div>
<input type="text" th:value="${username}" id="username" style="display: none"/>
</body>
<script type="text/javascript">
var webSocket;
var commWebSocket;
if ("WebSocket" in window) {
webSocket = new WebSocket("ws://localhost:8080/websocket/" + document.getElementById('username').value);
//連通之後的回調事件
webSocket.onopen = function () {
//webSocket.send( document.getElementById('username').value+"已經上線了");
console.log("已經連通了websocket");
setMessageInnerHTML("已經連通了websocket");
};
//接收後臺服務端的消息
webSocket.onmessage = function (evt) {
var received_msg = evt.data;
console.log("數據已接收:" + received_msg);
var obj = JSON.parse(received_msg);
console.log("可以解析成json:" + obj.messageType);
//1代表上線 2代表下線 3代表在線名單 4代表普通消息
if (obj.messageType == 1) {
//把名稱放入到selection當中供選擇
var onlineName = obj.username;
var option = "<option>" + onlineName + "</option>";
$("#onLineUser").append(option);
setMessageInnerHTML(onlineName + "上線了");
} else if (obj.messageType == 2) {
$("#onLineUser").empty();
var onlineName = obj.onlineUsers;
var offlineName = obj.username;
var option = "<option>" + "--所有--" + "</option>";
for (var i = 0; i < onlineName.length; i++) {
if (!(onlineName[i] == document.getElementById('username').value)) {
option += "<option>" + onlineName[i] + "</option>"
}
}
$("#onLineUser").append(option);
setMessageInnerHTML(offlineName + "下線了");
} else if (obj.messageType == 3) {
var onlineName = obj.onlineUsers;
var option = null;
for (var i = 0; i < onlineName.length; i++) {
if (!(onlineName[i] == document.getElementById('username').value)) {
option += "<option>" + onlineName[i] + "</option>"
}
}
$("#onLineUser").append(option);
console.log("獲取了在線的名單" + onlineName.toString());
} else {
setMessageInnerHTML(obj.fromusername + "對" + obj.tousername + "說:" + obj.textMessage);
}
};
//連接關閉的回調事件
webSocket.onclose = function () {
console.log("連接已關閉...");
setMessageInnerHTML("連接已經關閉....");
};
} else {
// 瀏覽器不支持 WebSocket
alert("您的瀏覽器不支持 WebSocket!");
}
//將消息顯示在網頁上
function setMessageInnerHTML(innerHTML) {
document.getElementById('message').innerHTML += innerHTML + '<br/>';
}
function closeWebSocket() {
//直接關閉websocket的連接
webSocket.close();
}
function send() {
var selectText = $("#onLineUser").find("option:selected").text();
if (selectText == "--所有--") {
selectText = "All";
} else {
setMessageInnerHTML(document.getElementById('username').value + "對" + selectText + "說:" + $("#text").val());
}
var message = {
"message": document.getElementById('text').value,
"username": document.getElementById('username').value,
"to": selectText
};
webSocket.send(JSON.stringify(message));
$("#text").val("");
}
</script>
</html>