Java基于NIO实现群聊系统
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2022-06-26 16:15:41
本文实例为大家分享了java基于nio实现群聊系统的具体代码,供大家参考,具体内容如下实例要求:1.编写一个 nio 群聊系统,实现服务器端和客户端之间的数据简单通讯(非阻塞)2.实现多人群聊3.服务...
本文实例为大家分享了java基于nio实现群聊系统的具体代码,供大家参考,具体内容如下
实例要求:
1.编写一个 nio 群聊系统,实现服务器端和客户端之间的数据简单通讯(非阻塞)
2.实现多人群聊
3.服务器端:可以监测用户上线,离线,并实现消息转发功能
4.客户端:通过 channel 可以无阻塞发送消息给其它所有用户,同时可以接受其它用户发送的消息(有服务器转发得到)
5.目的:进一步理解 nio 非阻塞网络编程机制
6.示意图分析和代码
// 服务端:
package com.atguigu.nio.groupchat; import java.io.ioexception; import java.net.inetsocketaddress; import java.nio.bytebuffer; import java.nio.channels.channel; import java.nio.channels.selectionkey; import java.nio.channels.selector; import java.nio.channels.serversocketchannel; import java.nio.channels.socketchannel; import java.util.iterator; public class groupchatserver { //定义属性 private selector selector; private serversocketchannel listenchannel; private static final int port = 6667; //构造器 //初始化工作 public groupchatserver() { try { //得到选择器 selector = selector.open(); //serversocketchannel listenchannel = serversocketchannel.open(); //绑定端口 listenchannel.socket().bind(new inetsocketaddress(port)); //设置非阻塞模式 listenchannel.configureblocking(false); //将该 listenchannel 注册到 selector listenchannel.register(selector, selectionkey.op_accept); } catch (ioexception e) { e.printstacktrace(); } } public void listen() { try { //循环处理 while (true) { int count = selector.select(); if (count > 0) { //有事件处理 // 遍历得到 selectionkey 集合 iterator<selectionkey> iterator = selector.selectedkeys().iterator(); while (iterator.hasnext()) { //取出 selectionkey selectionkey key = iterator.next(); //监听到 accept if (key.isacceptable()) { socketchannel sc = listenchannel.accept(); sc.configureblocking(false); //将该 sc 注册到 seletor sc.register(selector, selectionkey.op_read); //提示 system.out.println(sc.getremoteaddress() + " 上线 "); } if (key.isreadable()) {//通道发送read事件,即通道是可读的状态 // 处理读(专门写方法..) readdata(key); } //当前的 key 删除,防止重复处理 iterator.remove(); } } else { system.out.println("等待...."); } } } catch (exception e) { e.printstacktrace(); } finally { //发生异常处理.... } } //读取客户端消息 public void readdata(selectionkey key) { socketchannel channel = null; try { //得到 channel channel = (socketchannel) key.channel(); //创建 buffer bytebuffer buffer = bytebuffer.allocate(1024); int count = channel.read(buffer); //根据 count 的值做处理 if (count > 0) { //把缓存区的数据转成字符串 string msg = new string(buffer.array()); //输出该消息 system.out.println("form客户端:" + msg); //向其它的客户端转发消息(去掉自己),专门写一个方法来处理 sendinfotootherclients(msg, channel); } } catch (ioexception e) { try { system.out.println(channel.getremoteaddress() + "离线了.."); //取消注册 key.cancel(); //关闭通道 channel.close(); } catch (ioexception e2) { e2.printstacktrace(); } } } //转发消息给其它客户(通道) private void sendinfotootherclients(string msg, socketchannel self) throws ioexception { system.out.println("服务器转发消息中..."); //遍历所有注册到 selector 上的 socketchannel,并排除 self for (selectionkey key : selector.keys()) { //通过 key 取出对应的 socketchannel channel targetchannel = key.channel(); //排除自己 if (targetchannel instanceof socketchannel && targetchannel != self) { //转型 socketchannel dest = (socketchannel) targetchannel; //将 msg 存储到 buffer bytebuffer buffer = bytebuffer.wrap(msg.getbytes()); //将 buffer 的数据写入通道 dest.write(buffer); } } } public static void main(string[] args) { //创建服务器对象 groupchatserver groupchatserver = new groupchatserver(); groupchatserver.listen(); } }
// 客户端:
package com.atguigu.nio.groupchat; ~~import java.io.ioexception; import java.net.inetsocketaddress; import java.nio.bytebuffer; import java.nio.channels.selectionkey; import java.nio.channels.selector; import java.nio.channels.socketchannel; import java.util.iterator; import java.util.scanner; public class groupchatclient { //定义相关的属性 private final string host = "127.0.0.1";//服务器的ip private final int port = 6667;//服务器端口 private selector selector; private socketchannel socketchannel; private string username; //构造器,完成初始化工作 public groupchatclient() throws ioexception { selector = selector.open(); //连接服务器 socketchannel = socketchannel.open(new inetsocketaddress(host, port)); //设置非阻塞 socketchannel.configureblocking(false); //将 channel 注册到selector socketchannel.register(selector, selectionkey.op_read); //得到 username username = socketchannel.getlocaladdress().tostring().substring(1); system.out.println(username + " is ok..."); } //向服务器发送消息 public void sendinfo(string info) { info = username + " 说:" + info; try { socketchannel.write(bytebuffer.wrap(info.getbytes())); } catch (ioexception e) { e.printstacktrace(); } } //读取从服务器端回复的消息 public void readinfo() { try { int readchannels = selector.select(); if (readchannels > 0) {//有可以用的通道 iterator<selectionkey> iterator = selector.selectedkeys().iterator(); while (iterator.hasnext()) { selectionkey key = iterator.next(); if (key.isreadable()) { //得到相关的通道 socketchannel sc = (socketchannel) key.channel(); //得到一个 buffer bytebuffer buffer = bytebuffer.allocate(1024); //读取 sc.read(buffer); //把读到的缓冲区的数据转成字符串 string msg = new string(buffer.array()); system.out.println(msg.trim()); } } iterator.remove(); //删除当前的 selectionkey,防止重复操作 } else { //system.out.println("没有可以用的通道..."); } } catch (exception e) { e.printstacktrace(); } } public static void main(string[] args) throws exception { //启动我们客户端 groupchatclient chatclient = new groupchatclient(); //启动一个线程,每个 3 秒,读取从服务器发送数据 new thread() { public void run() { while (true) { chatclient.readinfo(); try { thread.currentthread().sleep(3000); } catch (interruptedexception e) { e.printstacktrace(); } } } }.start(); //发送数据给服务器端 scanner scanner = new scanner(system.in); while (scanner.hasnextline()) { string s = scanner.nextline(); chatclient.sendinfo(s); } } }
运行结果
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