2018.08.22 WebSocket 点对点 发送消息
2018-08-22 本文已影响95人
薛定谔的猴子
项目下载链接：https://pan.baidu.com/s/1VflXwPD6Pc2QQtRlzIyPQw 密码：n3f3
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依赖包
<dependency>
<groupId>javax</groupId>
<artifactId>javaee-api</artifactId>
<version>7.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>com.google.code.gson</groupId>
<artifactId>gson</artifactId>
<version>2.8.2</version>
</dependency>
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数据结构包装类
public class MessageDto {
public String from;
public String to;
public String content;
public String getFrom() {
return from;
}
public void setFrom(String from) {
this.from = from;
}
public String getTo() {
return to;
}
public void setTo(String to) {
this.to = to;
}
public String getContent() {
return content;
}
public void setContent(String content) {
this.content = content;
}
}
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ServerEndpoint
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import javax.websocket.OnClose;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint;
import com.google.gson.Gson;
@ServerEndpoint("/websocket")
public class WebSocket {
private String username;
private static ConcurrentMap<String, WebSocket> users = new ConcurrentHashMap<String, WebSocket>();
private Session session;
private void sendMessage(String mes) {
this.session.getAsyncRemote().sendText(mes);
}
@OnOpen
public void onOpen(Session session) {
this.session = session;
Map<String, List<String>> map = session.getRequestParameterMap();
username = map.get("username").get(0);//url中携带的参数
users.put(username, this);
}
@OnClose
public void onClose() {
users.remove(username);
}
@OnMessage
public void onMessage(String message, Session session) {
System.out.println("来自客户端的消息:" + message);
Gson gson = new Gson();
MessageDto mes = gson.fromJson(message, MessageDto.class);
if (mes.getTo() == null) {
Set<String> key = users.keySet();
for (String k : key) {
if (k.equals(mes.from)) continue;
users.get(k).sendMessage(message);
}
} else {
WebSocket toServlet = users.get(mes.getFrom());
WebSocket toServlet2 = users.get(mes.getTo());
if (null != toServlet) {
toServlet.sendMessage(message);
toServlet2.sendMessage(message);
}
}
}
}
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前端页面index.jsp
<%@ page language="java" pageEncoding="UTF-8" %>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<script type="text/javascript" src="http://code.jquery.com/jquery-2.1.4.min.js"></script>
<style type="text/css">
body {
width: 1200px;
}
</style>
</head>
<body>
<div>
<hr>
您的姓名:<input type="text" id="username">
<hr>
<button onclick="build()">建立连接</button>
</div>
<hr>
<div>
发送给:<input type="text" id="tousername">
</div>
<hr>
<div>
<textarea rows="10" cols="100" id="content">
</textarea>
<br> <br>
<button onclick="send()">发送</button>
</div>
<div id="showMessage"></div>
<script>
var websocket = null;
function build() {
var username = $("#username").val();
if ('WebSocket' in window) {
websocket = new WebSocket(
"ws://localhost:18080/websocket?username=" + username);
//连接成功建立的回调方法
websocket.onopen = function () {
$("#showMessage").append("<p color='red'>build success!</p>");
$("#tousername").append("<option>" + username + "</option>");
}
//连接发生错误的回调方法
websocket.onerror = function () {
alert("登录失败");
};
//连接关闭的回调方法
websocket.onclose = function () {
$("#showMessage").html("连接关闭");
};
//接收到消息的回调方法
websocket.onmessage = function (e) {
var jsonObject = JSON.parse(e.data);
$("#showMessage").append("<p>" + jsonObject.from + "对" + jsonObject.to + "说:" + jsonObject.content + "</p>");
};
} else
alert("Not Support!");
}
window.onbeforeunload = function () {
if (null != websocket)
websocket.close();
};
function send() {
var username = $("#username").val();
var content = $("#content").val();
var tousername = $("#tousername").val();
var mes = {
"from": username,
"to": tousername,
"content": content
};
if (null != websocket)
websocket.send(JSON.stringify(mes));
}
</script>
</body>
</html>
界面如下
