Java ServerSocket 实现聊天室功能（简易版）

大体实现功能可以选择房间，可以与房间中的用户进行实时的交流

说在前面的话:

serverSocket.accept() 会形成阻塞
scanner.hasNextLine() 和 scanner.nextLine() 也会形成阻塞
windows 下需要打开telnet服务。请自行百度
实现思路:

1. 用户连接上服务器后选择房间号，进入房间。进入房间后会向房间中所有的用户打印出用户进入房间的提醒。
2. 用户进入房间后，输入姓名即可发言。

1. 说起来很简单，代码实现更简单。我们需要一个保存房间用户的容器。我这里使用的是。

    // 保存聊天室中的用户数据     private static Map<String, List<Map<String, PrintWriter>>> charScnnerMap = new HashMap<>(); 

2. 使用 try-with-resource 语法防止出现资源未关闭的情况出现。
3. 直接上代码

package com.annie;  import com.sun.org.apache.xml.internal.resolver.readers.ExtendedXMLCatalogReader;  import java.io.*; import java.net.ServerSocket; import java.net.Socket; import java.util.*;  public class App {      // 保存聊天室中的用户数据     private static Map<String, List<Map<String, PrintWriter>>> charScnnerMap = new HashMap<>();      public static void print(List<Map<String, PrintWriter>> charNames, String conn) {         for (Map<String, PrintWriter> charName : charNames) {             Set<Map.Entry<String, PrintWriter>> entries = charName.entrySet();             for (Map.Entry<String, PrintWriter> entry : entries) {                 entry.getValue().println(conn);             }         }     }      public static void main(String[] args) throws InterruptedException {         charScnnerMap.put("1", new ArrayList<Map<String, PrintWriter>>());         charScnnerMap.put("2", new ArrayList<Map<String, PrintWriter>>());         charScnnerMap.put("3", new ArrayList<Map<String, PrintWriter>>());            // 监控本机端口 9189         try (ServerSocket serverSocket = new ServerSocket(9189)) {             while (true) {                 Socket accept = serverSocket.accept();                 new Thread(() -> {                     try (InputStream inputStream = accept.getInputStream();                          OutputStream outputStream = accept.getOutputStream();                          Scanner scanner = new Scanner(inputStream, "UTF-8");                          PrintWriter out = new PrintWriter(new OutputStreamWriter(outputStream, "UTF-8"), true)) {                           // 定位房间                         String number = "-1";                         out.println("Please enter the room number.(1-3): ");                         number = scanner.nextLine();                         if (!number.equals("1") && !number.equals("2") && !number.equals("3")) {                             while (true) {                                 out.println("Please enter the correct room.(1-3): ");                                 number = scanner.nextLine();                                 if (number.equals("1") || number.equals("2") || number.equals("3")) {                                     break;                                 }                             }                         }                          // 显示姓名                         out.println("Please enter your name: ");                         String name = scanner.nextLine();                         List<Map<String, PrintWriter>> charNames = charScnnerMap.get(number);                         Map<String, PrintWriter> m = new HashMap<>();                         m.put(name, out);                         charNames.add(m);                          // 打印内容                         print(charNames, "Welcome [" + name + "] to the room.");                          boolean b = true;                         while (b && scanner.hasNextLine()) {                             String s = scanner.nextLine();                             print(charNames, name + ": " + s);                              if (s.equals("BB")) {                                 print(charNames, "[" + name + "]Exit the room");                                 b = false;                             }                         }                     } catch (Exception e) {                         e.printStackTrace();                     }                 }).start();             }         } catch (IOException e) {             e.printStackTrace();         }     } } 

---

扩展内容
github
个人博客

来源：51CTO

作者：Annieؼ

链接：https://blog.csdn.net/weixin_39933264/article/details/100181312