4、java socket TCP 客戶端

package org.zhangmeng.test.eg_socket;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;
import java.net.SocketException;


/***
 * Socket 創建 
 *   Socket(InetAddress remoteAddr, int remotePort) 
 *   Socket(String remoteHost, int remotePort)  多個接口的主機上指定本地地址是有用的。
 *   Socket(InetAddress remoteAddr, int remotePort,InetAddress localAddr, int localPort) 
 *   Socket(String remoteHost, int remotePort, InetAddress localAddr, int localPort) 
 *   Socket()  必須顯示的進行連接
 * Socket 操作
 *   void connect(SocketAddress destination) 
 *   void connect(SocketAddress destination, int timeout) 
 *   InputStream getInputStream() 
 *   OutputStream getOutputStream() 
 *   void close() 
 *   void shutdownInput()   關閉TCP輸入流，任何沒有讀取的數據將被捨棄
 *   void shutdownOutput()
 * Socket 獲取屬性
 *   InetAddress getInetAddress() 
 *   int getPort() 
 *   InetAddress getLocalAddress() 
 *   int getLocalPort()
 *   SocketAddress getRemoteSocketAddress() 
 *   SocketAddress getLocalSocketAddress()
 * InetSocketAddress: 創建與訪問
 * 	 InetSocketAddress(InetAddress addr, int port) 
 *   InetSocketAddress(int port) 
 *   InetSocketAddress(String hostname, int port) 
 *   static InetSocketAddress createUnresolved(String host, int port) 
 *   boolean isUnresolved() 
 *   InetAddress getAddress() 
 *   int getPort() 
 *   String getHostName() 
 *   String toString()
 */
public class TCPEchoClient {
	public static void main(String[] args) throws IOException {
		if(args.length < 2 || args.length > 3){
			throw new IllegalArgumentException("Parameter(s) <Server> <Word> [<Port>]");
		}
		String server = args[0];
		//將要發送的字節數組
		byte[] data = args[1].getBytes();
		
		int serverPort = (args.length == 3) ? Integer.parseInt(args[2]) : 7;
		
		//創建Socket套接字
		Socket socket = new Socket(server, serverPort);
		
		System.out.println("Connected to server .. sending echo string .");
		
		InputStream in = socket.getInputStream();
		OutputStream out = socket.getOutputStream();
		
		//發送數據到socket server
		out.write(data);
		
		int totalBytesRcvd = 0;
		int bytesRcvd;
		while(totalBytesRcvd < data.length) {
			//讀入數據 一個write發送了數據，server可能分多個chunks接收到信息，返回時也被分割爲多塊數據返回。
			if((bytesRcvd = in.read(data,totalBytesRcvd,data.length - totalBytesRcvd)) == -1){
				throw new SocketException("Connection closed prematurely");
			}
			totalBytesRcvd += bytesRcvd;
		}
		System.out.println("Received:" + new String(data));
		socket.close();
	}
}