Spring和WebSocket整合详解
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概述
WebSocket 是一种网络通信协议。RFC6455 定义了它的通信标准。
WebSocket 是 HTML5 开始提供的一种在单个 TCP 连接上进行全双工通讯的协议。
HTTP 协议是一种无状态的、无连接的、单向的应用层协议。它采用了请求/响应模型。通信请求只能由客户端发起，服务端对请求做出应答处理。
这种通信模型有一个弊端：HTTP 协议无法实现服务器主动向客户端发起消息。
这种单向请求的特点，注定了如果服务器有连续的状态变化，客户端要获知就非常麻烦。大多数 Web 应用程序将通过频繁的异步JavaScript和XML（AJAX）请求实现长轮询。轮询的效率低，非常浪费资源（因为必须不停连接，或者 HTTP 连接始终打开）。
因此，工程师们一直在思考，有没有更好的方法。WebSocket 就是这样发明的。WebSocket 连接允许客户端和服务器之间进行全双工通信，以便任一方都可以通过建立的连接将数据推送到另一端。WebSocket 只需要建立一次连接，就可以一直保持连接状态。这相比于轮询方式的不停建立连接显然效率要大大提高。
Web浏览器和服务器都必须实现 WebSockets 协议来建立和维护连接。由于 WebSockets 连接长期存在，与典型的HTTP连接不同，对服务器有重要的影响。
基于多线程或多进程的服务器无法适用于 WebSockets，因为它旨在打开连接，尽可能快地处理请求，然后关闭连接。任何实际的 WebSockets 服务器端实现都需要一个异步服务器。
这里，我们基于Spring整合原生的WebSocket，实现简单的IM聊天功能。
Git地址：
Gitee
项目地址：
品茗IT-Spring之路专题
品茗IT：提供在线快速构建Spring项目工具。
开始搭建
依赖Jar包
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-websocket</artifactId>
<version>${spring.version}</version>
</dependency>
spring-websocket.xml
该xml文件仅作为配置文件的引入使用。
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.0.xsd ">
<bean id="annotationPropertyConfigurerWebSocket"
class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="order" value="1" />
<property name="ignoreUnresolvablePlaceholders" value="true" />
<property name="locations">
<list>
<value>classpath:websocket.properties</value>
</list>
</property>
</bean>
</beans>
websocket.properties保存一些自定义配置，这里没用上，就不贴出来了。
WebSocket配置监听
Spring整合WebSocket需要配置websocket的监听url。
SpringWebSocketConfig：
package com.cff.springwork.websocket.config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.socket.config.annotation.EnableWebSocket;
import org.springframework.web.socket.config.annotation.WebSocketConfigurer;
import org.springframework.web.socket.config.annotation.WebSocketHandlerRegistry;
import org.springframework.web.socket.handler.TextWebSocketHandler;
import com.cff.springwork.websocket.handler.WebsocketHandler;
@Configuration
@EnableWebMvc
@EnableWebSocket
public class SpringWebSocketConfig extends WebMvcConfigurerAdapter implements WebSocketConfigurer {
public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
registry.addHandler(webSocketHandler(),"/websocket").addInterceptors(new WebSocketInterceptor());
registry.addHandler(webSocketHandler(), "/sockjs").addInterceptors(new WebSocketInterceptor()).withSockJS();
}
@Bean
public TextWebSocketHandler webSocketHandler(){
return new WebsocketHandler();
}
}
WebSocket的session拦截处理
WebSocketInterceptor对WebSocket的连接进行过滤，可以对连接前和连接后自定义处理。
WebSocketInterceptor：
package com.cff.springwork.websocket.config;
import java.util.Map;
import javax.servlet.http.HttpSession;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.http.server.ServletServerHttpRequest;
import org.springframework.stereotype.Component;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.server.support.HttpSessionHandshakeInterceptor;
@Component
public class WebSocketInterceptor extends HttpSessionHandshakeInterceptor{
@Override
public boolean beforeHandshake(ServerHttpRequest request,
ServerHttpResponse response, WebSocketHandler wsHandler,
Map<String, Object> attributes) throws Exception {
System.out.println("Before Handshake");
if (request instanceof ServletServerHttpRequest) {
ServletServerHttpRequest servletRequest = (ServletServerHttpRequest) request;
HttpSession session = servletRequest.getServletRequest().getSession(false);
if (session != null) {
//使用userName区分WebSocketHandler，以便定向发送消息
String userName = (String) session.getAttribute("userId");
if (userName==null) {
userName="default";
}
attributes.put("userId",userName);
}
}
return super.beforeHandshake(request, response, wsHandler, attributes);
}
@Override
public void afterHandshake(ServerHttpRequest request,
ServerHttpResponse response, WebSocketHandler wsHandler,
Exception ex) {
System.out.println("After Handshake");
super.afterHandshake(request, response, wsHandler, ex);
}
}
消息处理（处理逻辑配合下面的聊天室）
WebsocketHandler负责处理消息发送接收的逻辑：
package com.cff.springwork.websocket.handler;
import java.io.IOException;
import java.util.List;
import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.socket.BinaryMessage;
import org.springframework.web.socket.CloseStatus;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketMessage;
import org.springframework.web.socket.WebSocketSession;
import org.springframework.web.socket.handler.TextWebSocketHandler;
import com.cff.springwork.websocket.memory.WebSocketUser;
public class WebsocketHandler extends TextWebSocketHandler {
protected Logger logger = LoggerFactory.getLogger(getClass());
public static WebSocketUser users = new WebSocketUser();
public WebsocketHandler(){
}
@Override
protected void handleTextMessage(WebSocketSession session,
TextMessage message) throws Exception {
logger.info("websocketmsg:{}",message.toString());
super.handleTextMessage(session, message);
String msg = message.getPayload();
logger.info("websocketmsg1:{}",msg);
if(StringUtils.isNotEmpty(msg)){
String param[] = msg.split("\\|");
String userName = (String)session.getAttributes().get("userName");
sendMessageToUser(param[1], new TextMessage(param[0]+"|"+userName+"|"+param[2]));
}
// TextMessage returnMessage = new TextMessage(message.getPayload()+" received at server");
// session.sendMessage(returnMessage);
}
@Override
public void afterConnectionEstablished(WebSocketSession session) throws Exception {
String userName = (String)session.getAttributes().get("userName");
String msgType="0000";
if(userName == null || "".equals(userName)){
long id = users.getWebsocketId();
logger.info("random UserId:{}",id);
users.putUserNameAndWebSocketSession(id+"", session);
session.sendMessage(new TextMessage(msgType+"|"+ id));
}else{
logger.info("UserName:{}",userName);
//users.putNickNameAndWebSocketSession(userInfo.getNickName(), session);
users.putUserNameAndWebSocketSession(userName, session);
session.sendMessage(new TextMessage(msgType+"|"+userName));
}
List<TextMessage> message = WebsocketHandler.getOfflineMsg(userName);
if( message !=null && message.size()!=0){
for(int i = 0; i < message.size(); i++){
WebsocketHandler.sendMessageToUser(userName, message.get(i));
}
}
}
@Override
public void afterConnectionClosed(WebSocketSession session, CloseStatus status) throws Exception {
//
// super.afterConnectionClosed(session, status);
users.removeWebSocketSession(session);
}
/**
* 给某个用户发送消息
*
* @param userName
* @param message
*/
public static void sendMessageToUser(String userName, TextMessage message) {
List<WebSocketSession> webUsers = users.getWebSocketSessionWithUserName(userName);
System.out.println(webUsers);
System.out.println(userName);
if (webUsers == null || webUsers.size() == 0){
users.putOfflineMsg(userName, message);
return;
}
for(int i =0; i < webUsers.size(); i++){
WebSocketSession user = webUsers.get(i);
System.out.println(user);
try {
if (user.isOpen()) {
user.sendMessage(message);
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
/**
* 给某个用户发送消息
*
* @param userName
* @param message
*/
public static void sendBinaryMessageToUser(String userName, BinaryMessage message) {
List<WebSocketSession> webUsers = users.getWebSocketSessionWithUserName(userName);
System.out.println(webUsers);
System.out.println(userName);
if (webUsers == null || webUsers.size() == 0){
//users.putOfflineMsg(userName, message);
return;
}
for(int i =0; i < webUsers.size(); i++){
WebSocketSession user = webUsers.get(i);
System.out.println(user);
try {
if (user.isOpen()) {
user.sendMessage(message);
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
public static List<TextMessage> getOfflineMsg(String userName){
return users.getOfflineMsgWithUserName(userName);
}
}
WebSocketUser是使用内存来存储用户：
package com.cff.springwork.websocket.memory;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketSession;
public class WebSocketUser {
private static Map<String,List<WebSocketSession>> userNameWebsession = null;
private static Map<WebSocketSession,String> webSessionUserName = null;
private static Map<String,List<TextMessage>> userNameWithOfflineMsg = null;
private static long websocketId = 100000000L;
public WebSocketUser(){
userNameWebsession = new ConcurrentHashMap<String,List<WebSocketSession>>();
webSessionUserName = new ConcurrentHashMap<WebSocketSession,String>();
userNameWithOfflineMsg = new ConcurrentHashMap<String,List<TextMessage>>();
}
public Map<String,List<WebSocketSession>> getUserNameWebsession(){
return userNameWebsession;
}
public Map<WebSocketSession,String> getWebSessionUserName(){
return webSessionUserName;
}
public String getUserNameWithWebSocketSession(WebSocketSession webSocketSession){
return webSessionUserName.get(webSocketSession);
}
public static Map<String, List<TextMessage>> getUserNameWithOfflineMsg() {
return userNameWithOfflineMsg;
}
public static void setUserNameWithOfflineMsg(Map<String, List<TextMessage>> userNameWithOfflineMsg) {
WebSocketUser.userNameWithOfflineMsg = userNameWithOfflineMsg;
}
public static void setUserNameWebsession(Map<String, List<WebSocketSession>> userNameWebsession) {
WebSocketUser.userNameWebsession = userNameWebsession;
}
public static void setWebSessionUserName(Map<WebSocketSession, String> webSessionUserName) {
WebSocketUser.webSessionUserName = webSessionUserName;
}
/**
* 根据昵称拿WebSocketSession
* @param nickName
* @return
*/
public List<WebSocketSession> getWebSocketSessionWithUserName(String userName){
return userNameWebsession.get(userName);
}
/**
* 移除失效的WebSocketSession
* @param webSocketSession
*/
public synchronized void removeWebSocketSession(WebSocketSession webSocketSession){
if (webSocketSession == null) return;
String nickName = webSessionUserName.get(webSocketSession);
webSessionUserName.remove(webSocketSession);
List<WebSocketSession> webSessoin = userNameWebsession.get(nickName);
if (webSessoin == null) return;
webSessoin.remove(webSocketSession);
}
/**
* 存放离线消息
* @param nickName
* @param msg
*/
public synchronized void putOfflineMsg(String userName, TextMessage msg){
if (userNameWithOfflineMsg.get(userName) == null){
List<TextMessage> msgList = new ArrayList<TextMessage>();
msgList.add(msg);
userNameWithOfflineMsg.put(userName, msgList);
}else{
List<TextMessage> msgList = userNameWithOfflineMsg.get(userName);
msgList.add(msg);
}
}
/**
* 根据昵称拿离线消息
* @param nickName
* @return
*/
public List<TextMessage> getOfflineMsgWithUserName(String userName){
return userNameWithOfflineMsg.get(userName);
}
/**
* 存放昵称和WebSocketSession
* @param nickName
* @param webSocketSession
*/
public synchronized void putUserNameAndWebSocketSession(String userName, WebSocketSession webSocketSession){
webSessionUserName.put(webSocketSession, userName);
if (userNameWebsession.get(userName) == null){
List<WebSocketSession> webSessoin = new ArrayList<WebSocketSession>();
webSessoin.add(webSocketSession);
userNameWebsession.put(userName, webSessoin);
}else{
List<WebSocketSession> webSessoin = userNameWebsession.get(userName);
webSessoin.add(webSocketSession);
}
}
/**
* 移除失效的WebSocketSession
* @param webSocketSession
*/
public synchronized long getWebsocketId(){
websocketId += 1;
return websocketId;
}
public static void main(String srga[]){
String test = "123456";
Boolean flag = true;
if(test == "012345678".substring(1, 7)){
flag = false;
}
System.out.println(flag);
}
}
聊天室
为了实现我们的简单聊天功能，我们需要前端进行配合。
websocketchat.jsp实现了简单的聊天室，支持文字、表情、文件等：
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<%@ include file="/common/head.jsp"%>
<!-- <script src="http://www.jq22.com/js/jq.js"></script> -->
<script type="text/javascript" src="${ctx}/js/jquery/jquery-3.2.1.min.js" ></script>
<script src="${ctx}/js/websocket/websocket.js"></script>
<script src="${ctx}/js/jquery/ajaxfileupload.js"></script>
<script src="${ctx}/js/jquery/jquery-browser.js"></script>
<script src="${ctx}/js/jquery/jquery.qqFace.js"></script>
<head>
<title>聊天室</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta http-equiv="content-script-type" content="text/javascript">
<meta http-equiv="content-style-type" content="text/css">
<style rel="stylesheet" type="text/css" media="all" />
body { text-align:left; margin:0; font:normal 12px Verdana, Arial;
background:#FFEEFF } form { margin:0; font:normal 12px Verdana,
Arial; } table,input { font:normal 12px Verdana, Arial; }
a:link,a:visited{ text-decoration:none; color:#333333; } a:hover{
text-decoration:none; color:#FF6600 } #main { width:400px;
position:absolute; left:600px; top:100px; background:#EFEFFF;
text-align:left; filter:Alpha(opacity=90) } #ChatHead {
text-align:right; padding:3px; border:1px solid #003399;
background:#DCDCFF; font-size:20px; color:#3366FF; cursor:move; }
#ChatHead a:link,#ChatHead a:visited, { font-size:14px;
font-weight:bold; padding:0 3px } #ChatBody { border:1px solid
#003399; border-top:none; padding:2px; } #ChatContent {
height:200px; padding:6px; overflow-y:scroll; word-break: break-all
}#ChatBtn { border-top:1px solid #003399; padding:2px }
</style>
<script language="javascript" type="text/javascript">
var ws = null;
var msgUser=null;
var muserId = null;
var nickName ="";
var contextPath = '${ctx}';
var imgName = null;
var fileImgSize = 0;
window.onbeforeunload = function()
{
disconnect(ws);
}
function ChatSetUser(user,userId) {
if(muserId != null && muserId != userId){
$("#ChatContent").html("");
}
msgUser = user;
muserId = userId;
imgName = msgUser;
//alert("owerId:" + nickName + "-----msgUser:" + msgUser);
//alert("userId:" + nickName + "-----userId:" + muserId);
if (msgUser == nickName) {
return;
}
if (msgUser == "") {
return;
}
ChatNew();
}
function gs(d) {
var t = document.getElementById(d);
if (t) {
return t.style;
} else {
return null;
}
}
function gs2(d, a) {
if (d.currentStyle) {
var curVal = d.currentStyle[a]
} else {
var curVal = document.defaultView
.getComputedStyle(d, null)[a]
}
return curVal;
}
function ChatHidden() {
gs("ChatBody").display = "none";
}
function ChatShow() {
gs("ChatBody").display = "";
}
function ChatClose() {
gs("main").display = "none";
//disconnect(ws);
}
function ChatNew() {
gs("main").display = "";
$("#ChatUsers").html(msgUser);
$('.emotion').qqFace({
id : 'facebox',
assign:'saytext',
path: contextPath+'/img/arclist/' //表情存放的路径
});
}
function ChatClear(obj) {
$("#ChatContent").html("");
}
function ChatRead() {
document.getElementById(msgUser).setAttribute('src', contextPath+'/img/users.png');
}
function ChatSend(obj) {
var o = obj.ChatValue;
var msg = replace_em(o.value);
if (o.value.length > 0) {
$("#ChatContent").append(
"<p align=\"right\"><strong>" + nickName + "(我) ：</strong>" + msg
+ "</p>");
var number = $("#ChatContent").scrollTop();
number += 16;
$("#ChatContent").scrollTop(number);
if(ws!=null){
ws.send("0001" + "|" + muserId + "|" + encodeURI(o.value));
}
o.value = '';
}
var img = obj.ChatFile;
if (img.value.length > 0){
$("#ChatContent").append(
"<p align=\"right\"><strong>" + nickName + "(我) ：</strong>" + img.value
+ "</p><br/>");
imgName = nickName+'（我）';
fileImgSize = img.files.length;
//alert(fileImgSize);
$.ajaxFileUpload({
//处理文件上传操作的服务器端地址(可以传参数,已亲测可用)
url:'${ctx}/webSocket/fileUpload?userId='+muserId,
secureuri:true, //是否启用安全提交,默认为false
fileElementId:'ChatFile', //文件选择框的id属性
dataType:'text', //服务器返回的格式,可以是json或xml等
success:function(data, status){ //服务器响应成功时的处理函数
//$("#ChatContent").append("<p align=\"right\">" + data + "</p><br/>");
},
error:function(data, status, e){ //服务器响应失败时的处理函数
$("#ChatContent").append('<p align=\"right\">图片上传失败，请重试！！</p><br/>');
imgName = msgUser;
}
});
}
}
if (document.getElementById) {
(function() {
if (window.opera) {
document.write("<input type='hidden' id='Q' value=' '>");
}
var n = 500;
var dragok = false;
var y, x, d, dy, dx;
function move(e) {
if (!e)
e = window.event;
if (dragok) {
d.style.left = dx + e.clientX - x + "px";
d.style.top = dy + e.clientY - y + "px";
return false;
}
}
function down(e) {
if (!e)
e = window.event;
var temp = (typeof e.target != "undefined") ? e.target
: e.srcElement;
if (temp.tagName != "HTML" | "BODY"
&& temp.className != "dragclass") {
temp = (typeof temp.parentNode != "undefined") ? temp.parentNode
: temp.parentElement;
}
if ('TR' == temp.tagName) {
temp = (typeof temp.parentNode != "undefined") ? temp.parentNode
: temp.parentElement;
temp = (typeof temp.parentNode != "undefined") ? temp.parentNode
: temp.parentElement;
temp = (typeof temp.parentNode != "undefined") ? temp.parentNode
: temp.parentElement;
}
if (temp.className == "dragclass") {
if (window.opera) {
document.getElementById("Q").focus();
}
dragok = true;
temp.style.zIndex = n++;
d = temp;
dx = parseInt(gs2(temp, "left")) | 0;
dy = parseInt(gs2(temp, "top")) | 0;
x = e.clientX;
y = e.clientY;
document.onmousemove = move;
return false;
}
}
function up() {
dragok = false;
document.onmousemove = null;
}
document.onmousedown = down;
document.onmouseup = up;
})();
}
function toIndex(){
window.location.href= contextPath + "/index.jsp";
}
$(function() {
if (ws == null) {
var url = getUrl();
//alert("url:"+url);
if (!url) {
return;
}
ws = new WebSocket(url);
connect(ws);
}
ChatClose();
// ChatSetUser("human","16888888888");
})
</script>
</head>
<body>
<div>
<div style="display: inline;">
<img style="width: 5%;margin-left: 100px;" alt="" src="${ctx}/img/logo.png" onclick="toIndex()"/>
</div>
<div style="display: inline; float: right">
<img style="width: 220px;display:block;margin-top: 15px;margin-right: 200px;" alt="" src="${ctx}/img/logoright.png"/>
</div>
</div>
<div id="main" class="dragclass" onclick="ChatRead()" style="left: 400px; top: 200px;">
<div id="ChatUsers" style="width:100px; padding:3px; font-size:15px;float:left; display:inline"></div>
<div id="ChatHead">
<a href="#" onclick="ChatHidden();">-</a> <a href="#"
onclick="ChatShow();">+</a> <a href="#" onclick="ChatClose();">x</a>
</div>
<div id="ChatBody">
<div id="ChatContent"></div>
<div id="ChatBtn">
<form action="" name="chat" method="post">
<textarea name="ChatValue" id="saytext" rows="3" style="width: 350px"></textarea>
<input name="Submit" type="button" value="发送"
onclick="ChatSend(this.form);" />
<input name="ClearMsg" type="button" value="清空记录"
onclick="ChatClear(this.form);" />
<input type="button" class="emotion" value="表情">
<input id="ChatFile" type="file" name="myfiles" multiple>
</form>
</div>
</div>
</div>
<div align="left" style="margin-top: 50px;margin-left: 20px;">
<p id=RandomContent>欢迎您，15607110725</p>
<p id=content></p>
</div>
</body>
</html>
这个jsp需要websocket.js配合：
function getUrl() {
var index = contextPath.lastIndexOf("/");
var urlPath = contextPath.substring(index, contextPath.length) + "/websocket";
if (window.location.protocol == 'http:') {
url = 'ws://' + window.location.host + urlPath;
} else {
url = 'wss://' + window.location.host + urlPath;
}
return url;
}
function disconnect(ws) {
if (ws != null) {
ws.close();
ws = null;
}
}
function replace_em(str){
// str = str.replace(/\</g,'<');
//
// str = str.replace(/\>/g,'>');
//
// str = str.replace(/\n/g,'<br/>');
str = str.replace(/\[em_([0-9]*)\]/g,'<img src="../../img/arclist/$1.gif" border="0" />');
return str;
}
function connect(ws) {
ws.onopen = function () {
$("#ChatContent").append("<small>连接成功。。。</small><br>");
};
ws.onmessage = function (event) {
if(typeof(event.data)=="string"){
var dataAll = event.data;
var indexMsgType = dataAll.indexOf("|");
var msgType = dataAll.substring(0,indexMsgType);
console.log('dataAll:'+dataAll);
if(msgType == "0000"){
webid = dataAll.substring(indexMsgType+1,dataAll.length);
$("#RandomContent").html("欢迎您,"+webid);
nickName = webid;
}else{
var data = dataAll.substring(indexMsgType+1,dataAll.length);
var index = data.indexOf("|");
var userId = data.substring(0,index);
var msg = decodeURI(data.substring(index+1,data.length));
var result = replace_em(msg);
if(document.getElementById(userId)){
document.getElementById(userId).setAttribute('src', contextPath+'/img/msgget.gif');
var number = $("#ChatContent").scrollTop();
//var number = $("#ChatContent").height();
number += 15;
$("#ChatContent").scrollTop(number);
$("#ChatContent").append("<strong>"+userId+" ：</strong>" + result + "<br>");
}else{
//var content = $("#content").html();
content = "<img src=\""+contextPath + "/img/msgget.gif\" id=\""
+ userId
+ "\" alt=\"\" style=\"cursor: pointer\" width='40px' "
+ "onclick=\"ChatSetUser('"
+ userId
+ "','"
+ userId
+ "')\" />"
+ userId
+ "<br><br>";
$("#content").append(content);
$("#ChatContent").append("<strong>"+userId+" ：</strong>" + result + "<br>");
}
}
}else{
var reader = new FileReader();
reader.onload = function(event){
if(event.target.readyState == FileReader.DONE){
var url = event.target.result;
if (imgName != msgUser){
$("#ChatContent").append("<p align=\"right\"><strong>"+imgName+" ：</strong>"+"<img src = "+url+" width='100px'/></p><br>");
}else{
$("#ChatContent").append("<strong>"+imgName+" ：</strong>"+"<img src = "+url+" width='100px'/><br>");
}
if (fileImgSize != 0){
fileImgSize = fileImgSize - 1;
}else{
imgName = msgUser;
}
}
}
reader.readAsDataURL(event.data);
}
};
ws.onclose = function (event) {
//alert('网络连接失败！');
};
}
以上已经支持表情和文字发送，要支持图片，需要我们自定义发送文件功能WebSocketController：
package com.cff.springwork.websocket.endpoint;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Controller;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.socket.BinaryMessage;
import com.cff.springwork.websocket.handler.WebsocketHandler;
@Controller("webSocketController")
@RequestMapping("/webSocket")
public class WebSocketController {
protected Logger logger = LoggerFactory.getLogger(getClass());
@RequestMapping(value="/fileUpload")
public void fileUpload(@RequestParam("userId") String userId, @RequestParam MultipartFile[] myfiles, HttpServletRequest request, HttpServletResponse response) throws IOException{
//可以在上传文件的同时接收其它参数
System.out.println("收到发往用户[" + userId + "]的文件上传请求");
//如果用的是Tomcat服务器，则文件会上传到\\%TOMCAT_HOME%\\webapps\\YourWebProject\\upload\\文件夹中
//这里实现文件上传操作用的是commons.io.FileUtils类,它会自动判断/upload是否存在,不存在会自动创建
String realPath = request.getSession().getServletContext().getRealPath("/upload");
System.out.println("路径[" + realPath + "]的文件上传请求");
System.out.println("文件数量："+myfiles.length);
realPath = "D:/doc/";
//设置响应给前台内容的数据格式
response.setContentType("text/plain; charset=UTF-8");
//上传文件的原名(即上传前的文件名字)
String originalFilename = null;
//如果只是上传一个文件,则只需要MultipartFile类型接收文件即可,而且无需显式指定@RequestParam注解
//如果想上传多个文件,那么这里就要用MultipartFile[]类型来接收文件,并且要指定@RequestParam注解
//上传多个文件时,前台表单中的所有<input type="file"/>的name都应该是myfiles,否则参数里的myfiles无法获取到所有上传的文件
for(MultipartFile myfile : myfiles){
if(myfile.isEmpty()){
response.setCharacterEncoding("UTF-8");
response.getWriter().write("102");
return;
}else{
originalFilename = myfile.getOriginalFilename();
System.out.println("文件原名: " + originalFilename);
System.out.println("文件名称: " + myfile.getName());
System.out.println("文件长度: " + myfile.getSize());
System.out.println("文件类型: " + myfile.getContentType());
System.out.println("========================================");
try {
//这里不必处理IO流关闭的问题,因为FileUtils.copyInputStreamToFile()方法内部会自动把用到的IO流关掉
//此处也可以使用Spring提供的MultipartFile.transferTo(File dest)方法实现文件的上传
//FileUtils.copyInputStreamToFile(myfile.getInputStream(), new File(realPath, originalFilename));
ByteArrayOutputStream swapStream = new ByteArrayOutputStream();
byte[] buff = new byte[100]; //buff用于存放循环读取的临时数据
int rc = 0;
InputStream is = myfile.getInputStream();
while ((rc = is.read(buff, 0, 100)) > 0) {
swapStream.write(buff, 0, rc);
}
byte[] in_b = swapStream.toByteArray(); //in_b为转换之后的结果
System.out.println("正在发送文件: ");
WebsocketHandler.sendBinaryMessageToUser(userId,new BinaryMessage(in_b));
} catch (IOException e) {
System.out.println("文件[" + originalFilename + "]上传失败,堆栈轨迹如下");
e.printStackTrace();
response.setCharacterEncoding("UTF-8");
response.getWriter().write("101");
return ;
}
}
}
response.setCharacterEncoding("UTF-8");
response.getWriter().write("200");
return;
}
}
详细完整代码，可以在Spring组件化构建中选择查看，并下载。
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