最近写了个Java NIO聊天室聊天的程序，NIO学习起来比较困难的，我的代码能给大家起到一个抛砖引玉的作用！
服务端：
package test.javanio;
/**
* @author
* @version
* CreateTime：2010-12-1 下午05:12:11
* Description：
*/
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.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.util.Date;
import java.util.Iterator;
import java.util.logging.Level;
import java.util.logging.Logger;
public class MySocketServer implements Runnable {
private boolean running;
private Selector selector;
String writeMsg;
StringBuffer sb = new StringBuffer();
SelectionKey ssckey;
public MySocketServer() {
running = true;
}
public void init() {
try {
selector = Selector.open();
ServerSocketChannel ssc = ServerSocketChannel.open();
ssc.configureBlocking(false);
ssc.socket().bind(new InetSocketAddress(2345));
ssckey = ssc.register(selector, SelectionKey.OP_ACCEPT);
System.out.println("server is starting..." + new Date());
} catch (IOException ex) {
Logger.getLogger(MySocketServer.class.getName()).log(Level.SEVERE,
null, ex);
}
}
public static void main(String[] args) {
MySocketServer server = new MySocketServer();
new Thread(server).start();
}
public void execute() {
try {
while (running) {
int num = selector.select();
if (num > 0) {
Iterator<SelectionKey> it = selector.selectedKeys()
.iterator();
while (it.hasNext()) {
SelectionKey key = it.next();
it.remove();
if (!key.isValid())
continue;
if (key.isAcceptable()) {
System.out.println("isAcceptable");
getConn(key);
} else if (key.isReadable()) {
System.out.println("isReadable");
readMsg(key);
}
else if (key.isValid() && key.isWritable()) {
if (writeMsg != null) {
System.out.println("isWritable");
writeMsg(key);
}
}
else
break;
}
}
Thread.yield();
}
} catch (IOException ex) {
Logger.getLogger(MySocketServer.class.getName()).log(Level.SEVERE,
null, ex);
}
}
private void getConn(SelectionKey key) throws IOException {
ServerSocketChannel ssc = (ServerSocketChannel) key.channel();
SocketChannel sc = ssc.accept();
sc.configureBlocking(false);
sc.register(selector, SelectionKey.OP_READ);
System.out.println("build connection :"
+ sc.socket().getRemoteSocketAddress());
}
private void readMsg(SelectionKey key) throws IOException {
sb.delete(0, sb.length());
SocketChannel sc = (SocketChannel) key.channel();
System.out.print(sc.socket().getRemoteSocketAddress() + " ");
ByteBuffer buffer = ByteBuffer.allocate(1024);
buffer.clear();
int len = 0;
StringBuffer sb = new StringBuffer();
while ((len = sc.read(buffer)) > 0) {
buffer.flip();
sb.append(new String(buffer.array(), 0, len));
}
if (sb.length() > 0)
System.out.println("get from client:" + sb.toString());
if (sb.toString().trim().toLowerCase().equals("quit")) {
sc.write(ByteBuffer.wrap("BYE".getBytes()));
System.out.println("client is closed "
+ sc.socket().getRemoteSocketAddress());
key.cancel();
sc.close();
sc.socket().close();
} else {
String toMsg = sc.socket().getRemoteSocketAddress() + "said:"
+ sb.toString();
System.out.println(toMsg);
writeMsg = toMsg;
/*
* Iterator<SelectionKey> it=key.selector().keys().iterator();
*
* while(it.hasNext()){ SelectionKey skey=it.next();
* if(skey!=key&&skey!=ssckey){ SocketChannel client=(SocketChannel)
* skey.channel(); client.write(ByteBuffer.wrap(toMsg.getBytes()));
* }
*
* }
*/
/*
*
* key.attach(toMsg);
* key.interestOps(key.interestOps()|SelectionKey.OP_WRITE);
*/
Iterator<SelectionKey> it = key.selector().keys().iterator();
while (it.hasNext()) {
SelectionKey skey = it.next();
if (skey != key && skey != ssckey) {
if (skey.attachment() != null) {
String str = (String) skey.attachment();
skey.attach(str + toMsg);
} else {
skey.attach(toMsg);
}
skey
.interestOps(skey.interestOps()
| SelectionKey.OP_WRITE);
}
}
selector.wakeup();// 可有可无
}
}
public void run() {
init();
execute();
}
private void writeMsg(SelectionKey key) throws IOException {
System.out.println("++++enter write+++");
SocketChannel sc = (SocketChannel) key.channel();
String str = (String) key.attachment();
sc.write(ByteBuffer.wrap(str.getBytes()));
key.interestOps(SelectionKey.OP_READ);
}
}
客户端：
package test.javanio;
/**
* @author
* @version
* CreateTime：2010-12-1 下午05:12:46
* Description：
*/
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.Currency.*;
public class MySocketClient implements Runnable {
Selector selector;
boolean running;
SocketChannel sc;
public MySocketClient() {
running = true;
}
public void init() {
try {
sc = SocketChannel.open();
sc.configureBlocking(false);
sc.connect(new InetSocketAddress("localhost", 2345));
} catch (IOException ex) {
Logger.getLogger(MySocketClient.class.getName()).log(Level.SEVERE,
null, ex);
}
}
public static void main(String[] args) {
MySocketClient client = new MySocketClient();
new Thread(client).start();
}
public void execute() {
int num = 0;
try {
while (!sc.finishConnect()) {
}
} catch (IOException ex) {
Logger.getLogger(MySocketClient.class.getName()).log(Level.SEVERE,
null, ex);
}
ReadKeyBoard rkb = new ReadKeyBoard();
new Thread(rkb).start();
while (running) {
try {
ByteBuffer buffer = ByteBuffer.allocate(1024);
buffer.clear();
StringBuffer sb = new StringBuffer();
Thread.sleep(500);
while ((num = sc.read(buffer)) > 0) {
sb.append(new String(buffer.array(), 0, num));
buffer.clear();
}
if (sb.length() > 0)
System.out.println(sb.toString());
if (sb.toString().toLowerCase().trim().equals("bye")) {
System.out.println("closed....");
sc.close();
sc.socket().close();
rkb.close();
running = false;
}
} catch (InterruptedException ex) {
Logger.getLogger(MySocketClient.class.getName()).log(
Level.SEVERE, null, ex);
} catch (IOException ex) {
Logger.getLogger(MySocketClient.class.getName()).log(
Level.SEVERE, null, ex);
}
}
}
public void run() {
init();
execute();
}
class ReadKeyBoard implements Runnable {
boolean running2 = true;
public ReadKeyBoard() {
}
public void close() {
running2 = false;
}
public void run() {
BufferedReader reader = new BufferedReader(new InputStreamReader(
System.in));
while (running2) {
try {
System.out.println("enter some commands:");
String str = reader.readLine();
sc.write(ByteBuffer.wrap(str.getBytes()));
} catch (IOException ex) {
Logger.getLogger(ReadKeyBoard.class.getName()).log(
Level.SEVERE, null, ex);
}
}
}
}
}
来源：https://www.cnblogs.com/lanzhi/p/6468381.html