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1.创建程序
打开idea输入 new project————>spring Initializr——>next 然后写入如下内容
接着 next 选择 core里面的lombok及web模块的 websocket 然后next——>finishj即可
2.创建文件
1.先在pom里面引入fastJson，代码如下
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.47</version>
</dependency>之后创建文件如下图所示
附上代码
（1） ChatController
package com.vic.chat.chatbase.controller;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.vic.chat.chatbase.util.WebSocketUtils;
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.List;
@ServerEndpoint(value = "/webSocket/{userId}")
@Component
public class ChatController {
@OnOpen
public void onOpen(@PathParam("userId") String userId, Session session) {
WebSocketUtils.put(userId, session);
}
@OnMessage
public void onMessage(String message) throws IOException {
JSONObject bean = JSON.parseObject(message);
broadcast((String)bean.get("msg"), (String)bean.get("from"),(String)bean.get("to"));
}
@OnError
public void onError(@PathParam("userId") String userId, Throwable t) {
WebSocketUtils.remove(userId);
}
@OnClose
public void onClose(@PathParam("userId") String userId) {
WebSocketUtils.remove(userId);
}
/**
* 发送消息
* @param message
* @param from
* @param to
*/
private void broadcast(String message, String from, String to) {
if ("-1".equals(to)) {
List<Session> sessions = WebSocketUtils.getOtherSession(from);
if (sessions.size() > 0) {
for (Session s : sessions) {
s.getAsyncRemote().sendText(message);
}
}
} else {
Session session = WebSocketUtils.get(to);
if (null != session && session.isOpen()) {
session.getAsyncRemote().sendText(message);
} else {
Session self = WebSocketUtils.get(from);
self.getAsyncRemote().sendText("对方已下线");
}
}
}
}
（2） LoginController
package com.vic.chat.chatbase.controller;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RestController;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
@RestController
public class LoginController {
private static Map<Integer,String> map = new ConcurrentHashMap<>();
@PostMapping("/login")
public Map<String,Object> login(Integer id){
Map<Integer,String> allMap=new ConcurrentHashMap<>();
allMap.put(1,"http://images.hanjiapz.com/upload/20171022/25e112639794494897e1e4478fa1c95fjpg?imageslim");
allMap.put(2,"http://images.hanjiapz.com/upload/20171104/5e2184f0bea2428b9a336d77f5ddec3cjpg?imageslim");
allMap.put(3,"http://ounwl7hpu.bkt.clouddn.com/upload/20170930/c4aa3f029cf1491e9bcf310868781abc");
allMap.put(4,"http://ounwl7hpu.bkt.clouddn.com/upload/20170901/9ee5503a838b4dbbad2fad15019e19b8");
allMap.put(5,"http://ounwl7hpu.bkt.clouddn.com/upload/20170819/a2c01030181142e387e81ab5e7b3b702");
allMap.put(6,"http://ounwl7hpu.bkt.clouddn.com/upload/20170819/a2c01030181142e387e81ab5e7b3b702");
allMap.put(7,"http://images.hanjiapz.com/upload/20171031/7d369c76c5034ee1a6e57974b920f3a0jpg?imageslim");
allMap.put(8,"http://ounwl7hpu.bkt.clouddn.com/upload/20170818/d2b7f76ffd854f688ffef48886af54d6");
String header=allMap.get(id);
String header2=map.get(id);
Map<String,Object> result=new HashMap<>();
result.put("code",500);
result.put("msg","账号不存在");
if (header!=null&&header2!=null){
result.put("msg","账号已经登陆了");
}
if(header!=null&&header2==null){
map.put(id,header);
result.put("code",200);
result.put("msg",header);
}
return result;
}
@PostMapping("/logout")
public Map<String,Object> logout(Integer id){
String header=map.get(id);
Map<String,Object> result=new HashMap<>();
result.put("code",500);
if (header!=null){
map.remove(id);
result.put("code",200);
}
return result;
}
}
（3）ChatConfig
package com.vic.chat.chatbase.util;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;
@Configuration
public class ChatConfig {
@Bean
public ServerEndpointExporter serverEndpointExporter() {
return new ServerEndpointExporter();
}
}
（4）WebSocketUtils
package com.vic.chat.chatbase.util;
import javax.websocket.Session;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
public class WebSocketUtils {
private static Map<String,Session> map = new ConcurrentHashMap<>();
private static final String PREFIX="mws";
public static void put(String userid,Session session){
map.put(getKey(userid),session);
}
public static Session get(String userid){
return map.get(getKey(userid));
}
public static List<Session> getOtherSession(String userid){
List<Session> result = new ArrayList<>();
Set<Map.Entry<String, Session>> set= map.entrySet();
for(Map.Entry<String, Session> s:set){
if(!s.getKey().equals(getKey(userid))){
result.add(s.getValue());
}
}
return result;
}
public static void remove(String userid){
map.remove(getKey(userid));
}
public static boolean hasConnection(String userid){
return map.containsKey(getKey(userid));
}
private static String getKey(String userid){
return PREFIX+"_"+userid;
}
}
（5）ChatBaseApplication
package com.vic.chat.chatbase;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class ChatBaseApplication {
public static void main(String[] args) {
SpringApplication.run(ChatBaseApplication.class, args);
}
}
好了，到此位置我们完成了一个简单的聊天系统的后端代码
3.代码逻辑理解
上面代码的逻辑是，通过LoginController 模拟登录。登陆之后，即可进行聊天，可以进行单聊和群聊。
下一步将会实现该代码的前端页面