server端代码
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.*;
import java.util.Set;
public class Server {
private static ServerSocketChannel serverSocketChannel;
private static Selector selector;
private static final Integer PORT = 8888;
public Server() {
try {
serverSocketChannel = ServerSocketChannel.open().bind(new InetSocketAddress(PORT));
selector = Selector.open();
serverSocketChannel.configureBlocking(false);
serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);
} catch (Exception e) {
e.printStackTrace();
}
}
private void listen() {
try {
while (true) {
int select = selector.select(3000);
if (select <= 0) {
// System.out.println("无监听事件，继续下一次监听");
continue;
}
Set<SelectionKey> selectionKeys = selector.selectedKeys();
for (SelectionKey selectionKey : selectionKeys) {
if (selectionKey.isAcceptable()) {
SocketChannel socketChannel = serverSocketChannel.accept();
socketChannel.configureBlocking(false);
socketChannel.register(selector, SelectionKey.OP_READ);
System.out.println(socketChannel.getRemoteAddress().toString() + "已经上线了");
}
if (selectionKey.isReadable()) {
SocketChannel socketChannel = (SocketChannel) selectionKey.channel();
ByteBuffer buffer = ByteBuffer.allocate(1024);
int read = 0;
try {
read = socketChannel.read(buffer);
}catch (Exception e){
System.out.println(socketChannel.getRemoteAddress() + "客戶端：离线了");
selectionKey.cancel();
socketChannel.close();
continue;
}
String msg = null;
if (read > 0) {
msg = new String(buffer.array());
System.out.println(socketChannel.getRemoteAddress() + "客户端：" + msg);
}
// 群发给其他的人
if (null != msg) {
sendInfoOtherPeople(msg, socketChannel);
}
}
// 防止重复消费
selectionKeys.remove(selectionKey);
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
private void sendInfoOtherPeople(String msg, SocketChannel self) {
try {
Set<SelectionKey> keys = selector.keys();
for (SelectionKey key : keys) {
Channel socketChannel = key.channel();
if (socketChannel instanceof SocketChannel && socketChannel != self) {
SocketChannel targetChannel = (SocketChannel) socketChannel;
targetChannel.write(ByteBuffer.wrap(msg.getBytes()));
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
Server server = new Server();
server.listen();
}
}
client端代码
import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.*;
import java.util.Scanner;
import java.util.Set;
public class Client {
private SocketChannel socketChannel;
private static final String HOST = "127.0.0.1";
private static final Integer PORT = 8888;
private Selector selector;
private static java.lang.String userName;
public Client() {
try {
socketChannel = socketChannel.open(new InetSocketAddress(HOST, PORT));
socketChannel.configureBlocking(false);
selector = Selector.open();
socketChannel.register(selector, SelectionKey.OP_READ);
userName = socketChannel.getLocalAddress().toString().substring(1);
} catch (Exception e) {
e.printStackTrace();
}
}
private void listen() {
try {
int select = selector.select(3000);
if (select <= 0) {
return;
}
Set<SelectionKey> selectionKeys = selector.selectedKeys();
for (SelectionKey selectionKey : selectionKeys) {
if (selectionKey.isReadable()) {
SocketChannel socketChannel = (SocketChannel) selectionKey.channel();
ByteBuffer buffer = ByteBuffer.allocate(1024);
int read = socketChannel.read(buffer);
if (read > 0) {
System.out.println(new String(buffer.array()));
}
}
selectionKeys.remove(selectionKey);
}
} catch (IOException e) {
e.printStackTrace();
}
}
private void sendInfo(String msg) {
try {
socketChannel.write(ByteBuffer.wrap(msg.getBytes()));
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
Client client = new Client();
new Thread(new Runnable() {
@Override
public void run() {
while (true) {
client.listen();
}
}
}).start();
// 发送数据
Scanner scanner = new Scanner(System.in);
while (scanner.hasNextLine()) {
String msg = scanner.next();
client.sendInfo(msg);
}
}
}
总结：代码实现的比较简单，欢迎大家前来补充指正。