第2章：基本套接字之TCP套接字

TCP客户端

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import java.net.Socket;import java.net.SocketException;import java.net.UnknownHostException;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;public class TCPEchoClient {/** * @param args * @throws IOException  * @throws UnknownHostException  */public static void main(String[] args) throws UnknownHostException, IOException {if (args.length < 2 || args.length > 3)throw new IllegalArgumentException("Parameters:<Server> <Word> [<Port>]");String server = args[0];//server name or ip address//Conver aaargument String to bytes using default character encodingbyte[] data = args[1].getBytes();int servPort = (args.length == 3) ? Integer.parseInt(args[2]) : 7;//Create socket that is connected to server on special portSocket socket = new Socket(server,servPort);System.out.println("Connected to server ... sending echo string");InputStream in = socket.getInputStream();OutputStream out = socket.getOutputStream();out.write(data);    //send the encoded string to the server//receive the same string back from the serverint totalByteRcvd = 0;   //total bytes received so farint bytesRcvd; //bytes received in last readwhile (totalByteRcvd < data.length) {if((bytesRcvd = in.read(data,totalByteRcvd,data.length-totalByteRcvd)) == -1)throw new SocketException("connection closed prematurely");totalByteRcvd += bytesRcvd;}  //data array is fullSystem.out.println("Received:" + new String(data));socket.close();}}

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TCP服务器端

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import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import java.net.ServerSocket;import java.net.Socket;import java.net.SocketAddress;public class TCPEchoServer {private static final int BUFSIZE =32;    //Size of reveive buffer/** * @param args * @throws IOException  */public static void main(String[] args) throws IOException {if(args.length != 1)throw new IllegalArgumentException("Parameter: <Port>");int servPort = Integer.parseInt(args[0]);//create a server socket to accept client connection requestsServerSocket servSocke = new ServerSocket(servPort);int recvMsgSize;    //size of receive messagebyte[] receiveBuf = new byte[BUFSIZE];    //receive bufferwhile (true) {  //run forever,accepting and servicing connectionsSocket clntSock = servSocke.accept();    //get client connectionSocketAddress clientAddress = clntSock.getRemoteSocketAddress();System.out.println("Handling client at " + clientAddress);InputStream in = clntSock.getInputStream();OutputStream out = clntSock.getOutputStream();//receive until client closes connection,indicated by -1 returnwhile ((recvMsgSize = in.read(receiveBuf)) != -1) {out.write(receiveBuf,0,recvMsgSize);}clntSock.close();    //close the socket,we are done with this client!}}}

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注意：

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1/TCP终端必须和特定的端口号关联，这样客户端才能够向该端口号发送链接请求

2/端口号第有效范围所0～65535（如果端口号被设为0，将选择任意没有使用第端口号）

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测试方法：（需要打开2个控制台）

在控制台启动服务器端：输入 ? java TCPEchoServer 8000（也可以所范围内第任意端口）

在控制台启动客户端： ? 输入 ? ?java TCPEchoClient localhost “hello” 8000 （我这里向本地发送tcp请求）

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我第输出所这样的——

服务器端输出：Handling client at /127.0.0.1:43389

客户端输出：Connected to server ... sending echo stringReceived:hello

成功了。

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其实可以修改程序固定好服务器，端口号，内容等参数的，这样就不用在控制台里面输入那么多东西了，直接运行服务器端和客户端就行了，很简单的，这里不多说了，有兴趣第朋友可以改好了，发上来交流一下

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