Chat system for the three core components NIO Selector, Channel, Buffer, the following NIO-based group to complete a
Server:
package com.jym.nio.groupChat;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.*;
import java.util.Iterator;
import java.util.Set;
/**
* @program: JymNetty
* @description: 服务端
* @author: jym
* @create: 2020/02/02
*/
public class GroupChatServer {
private Selector selector;
private ServerSocketChannel serverSocketChannel;
private final int PORT=6667;
/**
* 通过构造方法来初始化各个参数
*/
public GroupChatServer() {
try {
selector = Selector.open();
serverSocketChannel = ServerSocketChannel.open();
serverSocketChannel.configureBlocking(false);
serverSocketChannel.socket().bind(new InetSocketAddress(PORT));
serverSocketChannel.register(selector,SelectionKey.OP_ACCEPT);
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* @description:主要监听方法
*/
public void listen(){
try {
while (true){
int select = selector.select();
if(select>0){
Set<SelectionKey> selectionKeys = selector.selectedKeys();
Iterator<SelectionKey> iterator = selectionKeys.iterator();
while (iterator.hasNext()){
SelectionKey selectionKey = iterator.next();
if(selectionKey.isAcceptable()){
SocketChannel socketChannel = serverSocketChannel.accept();
socketChannel.configureBlocking(false);
socketChannel.register(selector,SelectionKey.OP_READ);
System.out.println(socketChannel.getRemoteAddress()+"上线了");
}
if(selectionKey.isReadable()){
readData(selectionKey);
}
iterator.remove();
}
}else {
System.out.println("系统正在等待人上线....");
}
}
} catch (Exception e) {
e.printStackTrace();
} finally {
}
}
/**
* @description:读取客户端发送的消息，并向其他客户端转发消息
* @param selectionKey
*/
private void readData(SelectionKey selectionKey){
SocketChannel socketChannel = null;
try {
socketChannel = (SocketChannel)selectionKey.channel();
socketChannel.configureBlocking(false);
ByteBuffer byteBuffer = ByteBuffer.allocate(1024);
int read = socketChannel.read(byteBuffer);
if(read>0){
String msg = new String(byteBuffer.array());
System.out.println("from客户端"+msg);
// 向其他客户端转发消息
sendInfoToOtherClient(msg,socketChannel);
}
} catch (IOException e) {
try {
System.out.println(socketChannel.getRemoteAddress()+"离线了");
// 取消注册
selectionKey.cancel();
socketChannel.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
/**
* @description: 向其他客户端转发消息
* @param msg
* @param socketChannel
*/
private void sendInfoToOtherClient(String msg, SocketChannel socketChannel){
System.out.println("服务器转发消息中");
// 遍历所有注册到selector的所有channel,排除自己
for (SelectionKey selectionKey : selector.keys()) {
Channel taGetChannel = selectionKey.channel();
if(taGetChannel instanceof SocketChannel && taGetChannel!=socketChannel){
SocketChannel socketChannel1 = (SocketChannel)taGetChannel;
ByteBuffer byteBuffer = ByteBuffer.wrap(msg.getBytes());
try {
socketChannel1.write(byteBuffer);
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
public static void main(String[] args) {
GroupChatServer groupChatServer = new GroupChatServer();
groupChatServer.listen();
}
}
Server:
package com.jym.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;
/**
* @program: JymNetty
* @description: 客户端
* @author: jym
* @create: 2020/02/02
*/
public class GroupChatClient {
private final String HOST = "127.0.0.1";
private final int PORT = 6667;
private Selector selector;
private SocketChannel socketChannel;
private String username;
public GroupChatClient() throws IOException {
selector = Selector.open();
// 连接服务器
socketChannel = SocketChannel.open(new InetSocketAddress(HOST, PORT));
this.socketChannel.configureBlocking(false);
this.socketChannel.register(selector, SelectionKey.OP_READ);
username = this.socketChannel.getRemoteAddress().toString().substring(1);
System.out.println(username+"isOK");
}
/**
* @description: 发送消息
* @param info
*/
public void sendInfo(String info){
info = username+"说:" + info;
try {
socketChannel.write(ByteBuffer.wrap(info.getBytes()));
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 读取消息
*/
public void readInfo(){
try {
int read = selector.select();
if(read>0){
Iterator<SelectionKey> iterator = selector.selectedKeys().iterator();
while (iterator.hasNext()){
SelectionKey selectionKey = iterator.next();
if(selectionKey.isReadable()){
SocketChannel channel = (SocketChannel)selectionKey.channel();
channel.configureBlocking(false);
ByteBuffer byteBuffer = ByteBuffer.allocate(1024);
int read1 = channel.read(byteBuffer);
if(read1>0){
System.out.println(new String(byteBuffer.array()).trim());
}
}
iterator.remove();
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
public static void main(String[] args) throws IOException {
// 启动客户端
GroupChatClient groupChatClient = new GroupChatClient();
// 启动一个线程,没隔三秒，读取发送的数据
new Thread(new Runnable() {
@Override
public void run() {
while (true){
groupChatClient.readInfo();
try {
Thread.currentThread().sleep(3000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}).start();
// 发送数据
Scanner scanner = new Scanner(System.in);
while (scanner.hasNext()){
String s = scanner.nextLine();
groupChatClient.sendInfo(s);
}
}
}
We start with the idea two clients a service-side:
Result:
server
Client 1:
Client 2:
Said here about the method starts two mian idea of:
Click the plus sign, select the application
enter the class name and then determine
and select our new application, click the Run button
Lack of study time, too shallow knowledge, that's wrong, please forgive me.
There are 10 kinds of people in the world, one is to understand binary, one is do not understand binary.
