Java基于NIO实现群聊功能

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我是靠谱客的博主纯真翅膀，最近开发中收集的这篇文章主要介绍Java基于NIO实现群聊功能，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

本文实例为大家分享了Java基于NIO实现群聊功能的具体代码，供大家参考，具体内容如下

一、群聊服务器

package com.dashu.netty.group_chat;

import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.*;
import java.nio.charset.StandardCharsets;
import java.util.Iterator;


public class GroupChatServer {


    /**
     * 初始化选择器
     */
    private Selector selector;

    /**
     * 初始化服务器网络通道
     */
    private ServerSocketChannel serverSocketChannel;

    /**
     * 端口
     */
    private static final int PORT = 6666;


    /**
     * 构造方法
     */
    public GroupChatServer() {

        try {

            //获取选择器
            selector = Selector.open();

            //获取服务器网络通道
            serverSocketChannel = ServerSocketChannel.open();

            //网络地址
            InetSocketAddress inetSocketAddress = new InetSocketAddress(PORT);

            //服务器网络通道绑定网络地址
            serverSocketChannel.socket().bind(inetSocketAddress);

            //设置服务器网络通道非阻塞
            serverSocketChannel.configureBlocking(false);

            //将服务器网络通道注册到选择器上，绑定连接请求事件
            serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);

        } catch (Exception e) {

            e.printStackTrace();

        }

    }


    /**
     * 监听客户端请求事件
     */
    public void listen() {


        try {

            //无限循环
            while (true) {

                //获取请求数
                int count = selector.select();

                //count大于0，则代表有请求进来
                if (count > 0) {


                    //获取请求集
                    Iterator<SelectionKey> selectionKeyIterator = selector.selectedKeys().iterator();

                    //遍历请求集
                    while (selectionKeyIterator.hasNext()) {

                        //得到请求
                        SelectionKey selectionKey = selectionKeyIterator.next();

                        //连接请求
                        if (selectionKey.isAcceptable()) {

                            //获取客户端网络通道
                            SocketChannel socketChannel = serverSocketChannel.accept();

                            //设置客户端网络通道非阻塞
                            socketChannel.configureBlocking(false);

                            //将客户端网络通道注册到选择器上
                            socketChannel.register(selector, SelectionKey.OP_READ);

                            System.out.println(socketChannel.getRemoteAddress() + "上线了");

                        }

                        //信息读取请求
                        if (selectionKey.isReadable()) {

                            //客户端信息读取
                            readData(selectionKey);

                        }

                        //移除请求
                        selectionKeyIterator.remove();

                    }


                } else {

                    System.out.println("等待...");

                }

            }
        } catch (Exception e) {
            e.printStackTrace();
        }

    }


    /**
     * 客户端信息读取
     *
     * @param selectionKey
     */
    private void readData(SelectionKey selectionKey) {

        //初始化客户端网络通道
        SocketChannel socketChannel = null;

        try {

            //获取客户端网络通道
            socketChannel = (SocketChannel) selectionKey.channel();

            //创建缓冲区
            ByteBuffer byteBuffer = ByteBuffer.allocate(1024);

            //读取客户端网络通道中的数据到缓冲区
            int count = socketChannel.read(byteBuffer);

            //判断缓冲区中是否有数据
            if (count > 0) {

                //将缓冲区的数据转换位字符串
                String message = new String(byteBuffer.array());

                System.out.println(message.trim());

                //将信息群发到其他客户端
                sendInfoToOtClients(message, socketChannel);

            }

        } catch (Exception e) {

            e.printStackTrace();

        }


    }

    /**
     * 将信息群发到其他客户端
     *
     * @param message
     * @param socketChannel
     */
    private void sendInfoToOtClients(String message, SocketChannel socketChannel) {

        //获取所有注册到选择器的客户端，并遍历
        for (SelectionKey selectionKey : selector.keys()) {

            //获取通道
            Channel channel = selectionKey.channel();

            //判断通道是否属于SocketChannel，同时不等于发送信息的客户端
            if (channel instanceof SocketChannel && channel != socketChannel) {

                //通道转换
                SocketChannel sc = (SocketChannel) channel;

                //将信息写入缓冲区
                ByteBuffer byteBuffer = ByteBuffer.wrap(message.getBytes(StandardCharsets.UTF_8));

                try {

                    //将缓冲区的数据写入通道
                    sc.write(byteBuffer);

                } catch (Exception e) {

                    e.printStackTrace();

                }

            }

        }

    }




    public static void main(String[] args) {

        GroupChatServer groupChatServer = new GroupChatServer();

        System.out.println("服务器启动，开始监听客户端请求...");
        groupChatServer.listen();

    }


}

二、客户端

package com.dashu.netty.group_chat;

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.nio.charset.StandardCharsets;
import java.util.Iterator;
import java.util.Scanner;

public class GroupChatClient {


    /**
     * 网络连接地址
     */
    private final String HOST = "127.0.0.1";

    /**
     * 端口
     */
    private final int PORT = 6666;

    /**
     * 初始化选择器
     */
    private Selector selector;

    /**
     * 初始化网络通道
     */
    private SocketChannel socketChannel;


    /**
     * 用户名
     */
    private String username;


    public GroupChatClient() {
        try {

            //获取选择器
            selector = Selector.open();


            //获取服务器网络地址
            InetSocketAddress inetSocketAddress = new InetSocketAddress(HOST, PORT);

            //获取网络通道
            socketChannel = SocketChannel.open(inetSocketAddress);

            //设置网络通道非阻塞
            socketChannel.configureBlocking(false);


            //将网络通道注册到选择器
            socketChannel.register(selector, SelectionKey.OP_READ);


            //获取用户名
            System.out.println("请输入用户名：");

            Scanner scanner = new Scanner(System.in);

            username = scanner.nextLine();

            System.out.println(username + " 进入群聊...");

        } catch (Exception e) {

            e.printStackTrace();

        }
    }


    /**
     * 向服务器发送信息
     *
     * @param message
     */
    public void sendInfo(String message) {

        message = username + ":" + message;

        try {

            //向通道写入数据
            socketChannel.write(ByteBuffer.wrap(message.getBytes(StandardCharsets.UTF_8)));

        } catch (Exception e) {

            e.printStackTrace();

        }

    }


    /**
     * 读取服务器发来的信息
     */
    public void readInfo() {
        try {

            //获取请求数
            int count = selector.select();

            if (count > 0) {

                //获取请求集
                Iterator<SelectionKey> selectionKeyIterator = selector.selectedKeys().iterator();

                //遍历请求集
                while (selectionKeyIterator.hasNext()) {

                    //获取请求
                    SelectionKey selectionKey = selectionKeyIterator.next();

                    //判断位读请求
                    if (selectionKey.isReadable()) {

                        //获取通道
                        SocketChannel sc = (SocketChannel) selectionKey.channel();

                        //创建缓冲区
                        ByteBuffer byteBuffer = ByteBuffer.allocate(1024);


                        //读取通道的数据到缓冲区
                        sc.read(byteBuffer);

                        //缓冲区数据转字符串
                        String message = new String(byteBuffer.array());

                        //输出
                        System.out.println(message.trim());

                    }

                    //移除已完成请求
                    selectionKeyIterator.remove();

                }

            }

        } catch (Exception e) {

            e.printStackTrace();

        }


    }


    public static void main(String[] args) {

        GroupChatClient groupChatClient = new GroupChatClient();

        /**
         * 开启一个线程，每3秒读取一次服务器发来的信息
         */
        new Thread() {
            @Override
            public void run() {
                while (true) {
                    groupChatClient.readInfo();
                    try {
                        Thread.sleep(3000);
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }
        }.start();


        //信息输入
        Scanner scanner = new Scanner(System.in);

        System.out.println("请输入信息：");
        while (scanner.hasNextLine()) {

            String s = scanner.nextLine();

            //信息发送
            groupChatClient.sendInfo(s);

            System.out.println("请输入信息：");

        }
    }


}