java学习小笔记（三.socket通信）【转】

三，socket通信
1.http://blog.csdn.net/kongxx/article/details/7288896这个人写的关于socket通信不错，循序渐进式的讲解，用代码示例说明，运用流和socket进行远程通讯

2.最简单的socket是一个服务端对应一个客户端
 server的写法

1. ServerSocket server = new ServerSocket();
2. Socket socket = server.accept();
3. BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
4. PrintWriter out = new PrintWriter(socket.getOutputStream());
5. while (true) {
6. String msg = in.readLine();
7. System.out.println(msg);
8. out.println("Server received " + msg);
9. out.flush();
10. if (msg.equals("bye")) {
11. break;
12. }
13. }
14. socket.close();

);

BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));

PrintWriter out = new PrintWriter(socket.getOutputStream());

BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));

while (true) {

String msg = reader.readLine();

out.println(msg);

out.flush();

if (msg.equals("bye")) {

break;

}

System.out.println(in.readLine());

}

socket.close();

);

os = new ObjectOutputStream(socket.getOutputStream());

User user = new User("user_" + i, "password_" + i);

os.writeObject(user);

os.flush();

is = new ObjectInputStream(new BufferedInputStream(socket.getInputStream()));

Object obj = is.readObject();

if (obj != null) {

user = (User)obj;

System.out.println("user: " + user.getName() + "/" + user.getPassword());

}

} catch(IOException ex) {

);

socket.connect(socketAddress,  * );

socket.setSoTimeout( * );

gzipos = new GZIPOutputStream(socket.getOutputStream());

oos = new ObjectOutputStream(gzipos);

User user = new User("user_" + i, "password_" + i);

oos.writeObject(user);

oos.flush();

gzipos.finish();

gzipis = new GZIPInputStream(socket.getInputStream());

ois = new ObjectInputStream(gzipis);

Object obj = ois.readObject();

if (obj != null) {

user = (User)obj;

System.out.println("user: " + user.getName() + "/" + user.getPassword());

}

} catch(IOException ex) {

);

);

));

serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);

while (selector.select() > ) {

Iterator<SelectionKey> it = selector.selectedKeys().iterator();

while (it.hasNext()) {

SelectionKey readyKey = it.next();

it.remove();

execute((ServerSocketChannel) readyKey.channel());  

1. private static void execute(ServerSocketChannel serverSocketChannel) throws IOException {
2. SocketChannel socketChannel = null;
3. try {
4. socketChannel = serverSocketChannel.accept();
5. MyRequestObject myRequestObject = receiveData(socketChannel);
6. logger.log(Level.INFO, myRequestObject.toString());
7. MyResponseObject myResponseObject = new MyResponseObject(
8. "response for " + myRequestObject.getName(),
9. "response for " + myRequestObject.getValue());
10. sendData(socketChannel, myResponseObject);

1. MyRequestObject myRequestObject = null;
2. ByteArrayOutputStream baos = new ByteArrayOutputStream();
3. ByteBuffer buffer = ByteBuffer.allocate();
4. try {
5. byte[] bytes;
6. int size = ;
7. while ((size = socketChannel.read(buffer)) >= ) {
8. buffer.flip();
9. bytes = new byte[size];
10. buffer.get(bytes);
11. baos.write(bytes);
12. buffer.clear();
13. }
14. bytes = baos.toByteArray();
15. Object obj = SerializableUtil.toObject(bytes);
16. myRequestObject = (MyRequestObject)obj;

1. sendData(SocketChannel socketChannel, MyResponseObject myResponseObject) throws IOException {
2. byte[] bytes = SerializableUtil.toBytes(myResponseObject);
3. ByteBuffer buffer = ByteBuffer.wrap(bytes);
4. socketChannel.write(buffer);

client的写法

1. socketChannel = SocketChannel.open();
2. SocketAddress socketAddress = new InetSocketAddress("localhost", );
3. socketChannel.connect(socketAddress);
4. MyRequestObject myRequestObject = new MyRequestObject("request_" + idx, "request_" + idx);
5. logger.log(Level.INFO, myRequestObject.toString());
6. sendData(socketChannel, myRequestObject);
7. MyResponseObject myResponseObject = receiveData(socketChannel);
8. logger.log(Level.INFO, myResponseObject.toString());

1. private void sendData(SocketChannel socketChannel, MyRequestObject myRequestObject) throws IOException {
2. byte[] bytes = SerializableUtil.toBytes(myRequestObject);
3. ByteBuffer buffer = ByteBuffer.wrap(bytes);
4. socketChannel.write(buffer);
5. socketChannel.socket().shutdownOutput();
   1. private MyResponseObject receiveData(SocketChannel socketChannel) throws IOException {
   2. MyResponseObject myResponseObject = null;
   3. ByteArrayOutputStream baos = new ByteArrayOutputStream();
   4. try {
   5. ByteBuffer buffer = ByteBuffer.allocateDirect();
   6. byte[] bytes;
   7. int count = ;
   8. while ((count = socketChannel.read(buffer)) >= ) {
   9. buffer.flip();
   10. bytes = new byte[count];
   11. buffer.get(bytes);
   12. baos.write(bytes);
   13. buffer.clear();
   14. }
   15. bytes = baos.toByteArray();
   16. Object obj = SerializableUtil.toObject(bytes);
   17. myResponseObject = (MyResponseObject) obj;
   18. socketChannel.socket().shutdownInput();

   return myResponseObject;

上面的例子都需要先运行server再运行client。