Server socket編程的時候，一個SERVER服務一個連接的時候，是阻塞線程的，除非用多線程來處理。
NIO只使用一條線程即可以處理多個連接。是基于事件的模式，即產生事件的時候，通知客戶端處理相應的事件。
1)server端代碼
/**
*
* @author Jeff
*
*/
public class HelloWorldServer {
static int BLOCK = 1024;
static String name = "";
protected Selector selector;
protected ByteBuffer clientBuffer = ByteBuffer.allocate(BLOCK);
protected CharsetDecoder decoder;
static CharsetEncoder encoder = Charset.forName("GB2312").newEncoder();
public HelloWorldServer(int port) throws IOException {
selector = this.getSelector(port);
Charset charset = Charset.forName("GB2312");
decoder = charset.newDecoder();
}
// 獲取Selector
protected Selector getSelector(int port) throws IOException {
ServerSocketChannel server = ServerSocketChannel.open();
Selector sel = Selector.open();
server.socket().bind(new InetSocketAddress(port));
server.configureBlocking(false);
server.register(sel, SelectionKey.OP_ACCEPT);
return sel;
}
// 監聽端口
public void listen() {
try {
for (;;) {
selector.select();
Iterator iter = selector.selectedKeys().iterator();
while (iter.hasNext()) {
SelectionKey key = (SelectionKey) iter.next();
iter.remove();
process(key);
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
// 處理事件
protected void process(SelectionKey key) throws IOException {
if (key.isAcceptable()) { // 接收請求
ServerSocketChannel server = (ServerSocketChannel) key.channel();
SocketChannel channel = server.accept();
//設置非阻塞模式
channel.configureBlocking(false);
channel.register(selector, SelectionKey.OP_READ);
} else if (key.isReadable()) { // 讀信息
SocketChannel channel = (SocketChannel) key.channel();
int count = channel.read(clientBuffer);
if (count > 0) {
clientBuffer.flip();
CharBuffer charBuffer = decoder.decode(clientBuffer);
name = charBuffer.toString();
// System.out.println(name);
SelectionKey sKey = channel.register(selector,
SelectionKey.OP_WRITE);
sKey.attach(name);
} else {
channel.close();
}
clientBuffer.clear();
} else if (key.isWritable()) { // 寫事件
SocketChannel channel = (SocketChannel) key.channel();
String name = (String) key.attachment();
ByteBuffer block = encoder.encode(CharBuffer
.wrap("Hello !" + name));
channel.write(block);
//channel.close();
}
}
public static void main(String[] args) {
int port = 8888;
try {
HelloWorldServer server = new HelloWorldServer(port);
System.out.println("listening on " + port);
server.listen();
} catch (IOException e) {
e.printStackTrace();
}
}
}
server主要是讀取client發過來的信息，并返回一條信息
2)client端代碼
/**
*
* @author Jeff
*
*/
public class HelloWorldClient {
static int SIZE = 10;
static InetSocketAddress ip = new InetSocketAddress("localhost", 8888);
static CharsetEncoder encoder = Charset.forName("GB2312").newEncoder();
static class Message implements Runnable {
protected String name;
String msg = "";
public Message(String index) {
this.name = index;
}
public void run() {
try {
long start = System.currentTimeMillis();
//打開Socket通道
SocketChannel client = SocketChannel.open();
//設置為非阻塞模式
client.configureBlocking(false);
//打開選擇器
Selector selector = Selector.open();
//注冊連接服務端socket動作
client.register(selector, SelectionKey.OP_CONNECT);
//連接
client.connect(ip);
//分配內存
ByteBuffer buffer = ByteBuffer.allocate(8 * 1024);
int total = 0;
_FOR: for (;;) {
selector.select();
Iterator iter = selector.selectedKeys().iterator();
while (iter.hasNext()) {
SelectionKey key = (SelectionKey) iter.next();
iter.remove();
if (key.isConnectable()) {
SocketChannel channel = (SocketChannel) key
.channel();
if (channel.isConnectionPending())
channel.finishConnect();
channel
.write(encoder
.encode(CharBuffer.wrap(name)));
channel.register(selector, SelectionKey.OP_READ);
} else if (key.isReadable()) {
SocketChannel channel = (SocketChannel) key
.channel();
int count = channel.read(buffer);
if (count > 0) {
total += count;
buffer.flip();
while (buffer.remaining() > 0) {
byte b = buffer.get();
msg += (char) b;
}
buffer.clear();
} else {
client.close();
break _FOR;
}
}
}
}
double last = (System.currentTimeMillis() - start) * 1.0 / 1000;
System.out.println(msg + "used time :" + last + "s.");
msg = "";
} catch (IOException e) {
e.printStackTrace();
}
}
}
public static void main(String[] args) throws IOException {
String names[] = new String[SIZE];
for (int index = 0; index < SIZE; index++) {
names[index] = "jeff[" + index + "]";
new Thread(new Message(names[index])).start();
}
}
}