java结合NIO实现的聊天程序

import java.net.*;
import java.nio.*;
import java.nio.channels.*;
import java.nio.charset.*;
import java.awt.*;
import java.awt.event.*;
public class ChatClient {
private SocketChannel sc = null;
private String name = null;
private Frame f;
private TextArea ta;
private TextField tf;
private boolean runnable = true;
public static void main(String[] args){
ChatClient cc = new ChatClient();
cc.createUI();
cc.inputName();
cc.connect();
new ReceiveThread(cc,cc.getTextArea()).start();
}
public SocketChannel getSc(){
return sc;
}
public void setName(String name){
this.name = name;
}
public TextArea getTextArea(){
return ta;
}
public TextField getTextField(){
return tf;
}
public boolean getRunnable(){
return runnable;
}
public void stop(){
runnable = false;
}

public void shutDown(){
try{
sc.write(ByteBuffer.wrap("bye".getBytes("UTF-8")));
ta.append("Exit in 5 seconds!");
this.stop();
Thread.sleep(5000);
sc.close();
}catch(Exception e){
e.printStackTrace();
}
System.exit(0);
}
public void createUI(){
f = new Frame("Client");
ta = new TextArea();
ta.setEditable(false);
tf = new TextField();
Button send = new Button("Send");
Panel p = new Panel();
p.setLayout(new BorderLayout());
p.add(tf,"Center");
p.add(send,"East");
f.add(ta,"Center");
f.add(p,"South");
MyClientListener listener = new MyClientListener(this);
send.addActionListener(listener);
tf.addActionListener(listener);
f.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){
ChatClient.this.shutDown();
}
});
f.setSize(400,400);
f.setLocation(600,0);
f.setVisible(true);
tf.requestFocus();
}
public boolean connect()(){
try{
sc = SocketChannel.open();
//"czd"为目标计算机名
InetSocketAddress isa = new InetSocketAddress("172.16.32.63",8814);
sc.connect(isa);
sc.configureBlocking(false);
sc.write(ByteBuffer.wrap(name.getBytes("UTF-8")));
}catch(Exception e){
e.printStackTrace();
}
return true;
}

public void inputName(){
String name = javax.swing.JOptionPane.showInputDialog("Input Your Name:");
this.setName(name);
f.setTitle(name);
}
}
class MyClientListener implements ActionListener{
private ChatClient client;
public MyClientListener(ChatClient client){
this.client = client;
}
public void actionPerformed(ActionEvent e){
TextField tf = client.getTextField();
String info = tf.getText();
if(info.equals("bye")){
client.shutDown();
}else{
try{
client.getSc().write(ByteBuffer.wrap(info.getBytes("UTF-8")));
}catch (Exception e1) {
e1.printStackTrace();
}
}
tf.setText("");
tf.requestFocus();
}
}
class ReceiveThread extends Thread{
private ChatClient client;
private TextArea ta;
public ReceiveThread(ChatClient client,TextArea ta){
this.client = client;
this.ta = ta;
}
public void run(){
SocketChannel sc = client.getSc();
ByteBuffer byteBuffer = ByteBuffer.allocate(2048);
CharBuffer charBuffer = null;
Charset charset = Charset.forName("UTF-8");
CharsetDecoder decoder = charset.newDecoder();
String msg = null;
int n = 0;
try{
while(client.getRunnable()){
n = sc.read(byteBuffer);
if(n>0){
byteBuffer.flip();
charBuffer = decoder.decode(byteBuffer);
msg = charBuffer.toString();
ta.append(msg + "\n");
}
byteBuffer.clear();
Thread.sleep(500);
}
}catch(Exception e){
e.printStackTrace();
System.exit(0);
}
}
}

import java.io.*;
import java.nio.*;
import java.nio.channels.*;
import java.nio.charset.*;
import java.net.*;
import java.util.*;

public class ICQServer {
private Selector select()or = null;
private ServerSocketChannel ssc = null;
//服务器端通信端口号
private int port = 8814;
//在线用户列表
private Hashtable<String, SocketChannel> userList = null;

public ICQServer() {}

public ICQServer(int port) {
this.port = port;
}

//初始化服务器
public void init() {
try {
//创建选择器对象
selector = Selector.open();
//创建ServerSocketChannel
ssc = ServerSocketChannel.open();
//设置ServerSocketChannel为非阻塞模式
ssc.configureBlocking(false);
InetAddress ip = InetAddress.getLocalHost();
System.out.println("主机地址 --------> " + ip);
InetSocketAddress isa = new InetSocketAddress(ip, port);
//将与本通道相关的服务器套接字对象绑定到指定地址和端口
ssc.socket()().bind(isa);
//创建在线用户列表
userList = new Hashtable<String, SocketChannel> ();
} catch (IOException e) {
System.out.println("初始化服务器时异常，原因  -------->  " + e.getMessage());
}
}

//启动服务器
public void start() {
try {
//将ServerSocketChannel注册到Selector上，准备接收新连接请求
SelectionKey acceptKey = ssc.register(selector, SelectionKey.OP_ACCEPT);
SocketChannel sc;
int n;
String name; //用户名
String msg; //用户发言信息
while (true) {
//选择当前所有处于就绪状态的通道所对应的选择键,并将这些键组成已选择键集
n = selector.select(); //n为已选择键集中键的个数
if (n > 0) {
//获取此选择器的已选择键集。
Set readyKeys = selector.selectedKeys();
Iterator it = readyKeys.iterator();
//遍历当前已选择键集
while (it.hasNext()) {
SelectionKey key = (SelectionKey) it.next();
//从当前已选择键集中移除当前键，避免重复处理
it.remove();
//如果当前键对应的通道已准备好接受新的套接字连接
if (key.isAcceptable()) {
//获取当前键对应的可选择通道（ServerSocketChannel）
ssc = (ServerSocketChannel) key.channel();
//接收新的套接字连接请求，返回新建的SocketChannel
sc = (SocketChannel) ssc.accept();
//如果有新用户接入
if (sc != null) {
//接收新上线用户姓名
name = readMessage(sc);
//设置新建的SocketChannel为非阻塞模式
sc.configureBlocking(false);
//将新建的SocketChannel注册到Selector上，准备进行数据"写"操作，
//并将当前用户名以附件的方式附带记录到新建的选择键上。
SelectionKey newKey = sc.register(selector,SelectionKey.OP_WRITE, name);
//将新上线用户信息加入到在线用户列表
userList.put(name, sc);
//发送"新用户上线"通知
transmitMessage(name + " in!", "--Server Info--");
}
//否则，如果当前键对应的通道已准备好进行"写"操作
}else if (key.isWritable()) {
//获取当前键对应的可选择通道（SocketChannel）
sc = (SocketChannel) key.channel();
//接收该通道相应用户的发言信息
msg = readMessage(sc);
//获取选择键上附带记录的当前用户名
name = key.attachment().toString();
//如果用户提出要下线
if (msg.equals("bye")) {
//从在线用户列表中移除当前用户
userList.remove(name);
//注销当前选择键对应的注册关系
key.cancel();
//关闭当前可选择通道
sc.close();
//发送"用户下线"通知
transmitMessage(name + " out!", "--Server Info--");
//否则，如果接收到的用户发言信息非空（""）
} else if (msg.length() > 0) {
//转发用户发言信息
transmitMessage(msg, name);
}
}
}
}
//延时循环，降低服务器端处理负荷
Thread.sleep(500);
}
}catch (Exception e) {
System.out.println("启动服务器时异常，原因  -------->  " + e.getMessage());
}
}

//转发用户发言信息
public void transmitMessage(String msg, String name) {
try {
ByteBuffer buffer = ByteBuffer.wrap( (name + ":" + msg).getBytes("UTF-8"));
//将字节数组包装到缓冲区中
Collection channels = userList.values();
SocketChannel sc;
for (Object o : channels) {
sc = (SocketChannel) o;
sc.write(buffer);
//将缓冲区数据写入聊天面板(TextArea)
buffer.flip();
//将缓冲区ByteBuffer的极限值设置为当前数据实际大小，将缓冲区的值设置为0
}
}catch (Exception e) {
System.out.println("转发用户发言信息时异常，原因  -------->  " + e.getMessage());
}
}

//接收用户发言信息
public String readMessage(SocketChannel sc) {
String result = null;
int n = 0;
ByteBuffer buf = ByteBuffer.allocate(1024);
try {
n = sc.read(buf);
buf.flip();
Charset charset = Charset.forName("UTF-8");
CharsetDecoder decoder = charset.newDecoder();
CharBuffer charBuffer = decoder.decode(buf);
result = charBuffer.toString();
}catch (IOException e) {
System.out.println("接收用户发言信息时异常，原因  -------->  " + e.getMessage());
}
return result;
}

public static void main(String args[]) {
ICQServer server = new ICQServer();
server.init();
server.start();
}
}