java 网络编程

package org.example.network;import java.net.InetAddress;/** *  * DOC InetAddress类的使用<br/> * 该类的功能是代表一个IP地址，并且将IP地址和域名相关的操作方法包含在该类的内部 常用的功能->获取ip地址 */public class Main1 {    public static void main(String[] args) throws Exception {        // 使用域名创建对象        InetAddress inet1 = InetAddress.getByName("www.baidu.com");        // 使用IP地址创建对象        InetAddress inet2 = InetAddress.getByName("127.0.0.1");        // 获取本机地址对象        InetAddress inet3 = InetAddress.getLocalHost();        String hostName = inet3.getHostName();        String ip = inet3.getHostAddress();        System.out.println("inet1--->" + inet1);        System.out.println("inet2--->" + inet2);        System.out.println("inet3--->" + inet3);        System.out.println("inet3--hostName->" + hostName);        System.out.println("inet3--ip->" + ip);        // test results:        /**         * inet1--->www.baidu.com/220.181.112.143 <br/>         * inet2--->/127.0.0.1 <br/>         * inet3--->yzb-PC/192.168.1.132 <br/>         * inet3--hostName->yzb-PC <br/>         * inet3--hostAddress->192.168.1.132         */    }}

package org.example.network;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import java.net.ServerSocket;import java.net.Socket;/** *  * DOC TCP编程<br/> * TCP就像打电话一样，流程是：<br/> * 客户端：建立连接-》交换数据-》释放连接<br/> * 服务器端:监听端口-》建立连接-》交换数据-》施放连接 *  */public class Main2 {    public static void main(String[] args) {        Main2 main = new Main2();        // main.new Server().startServer();        main.new Client().request();    }    /**     * DOC 客户端     *      */    public class Client {        public void request() {            Socket socket = null;            OutputStream out = null;            InputStream in = null;            String ip = "127.0.0.1";// 要连接的ip地址            int port = 9090;// 要连接的端口号            String data = "hello server.";// 要发送的内容            try {                // 建立连接                socket = new Socket(ip, port);                // 获得输出流                out = socket.getOutputStream();                // 发送消息                out.write(data.getBytes());                // 获取输入流                in = socket.getInputStream();                byte bb[] = new byte[1024];                // 获取反应信息                int n = in.read(bb);                System.out.println("client端获取的反馈信息：" + new String(bb, 0, n));            } catch (Exception e) {                e.printStackTrace();            } finally {                try {                    // 关闭连接                    in.close();                    out.close();                    socket.close();                } catch (Exception e) {                    e.printStackTrace();                }            }        }    }    public class Server {        public void startServer() {            ServerSocket serverSocket = null;            Socket socket = null;            InputStream in = null;            OutputStream out = null;            int port = 9090;// 监听的端口号            try {                // 启动服务，监听端口号                serverSocket = new ServerSocket(port);                // 该操作会阻塞线程，直到获取到一个请求，才会往下走                socket = serverSocket.accept();                // 获取输入的信息                in = socket.getInputStream();                byte bb[] = new byte[1024];                int n = in.read(bb);                System.out.println("服务器端收到的内容:" + new String(bb, 0, n));                // 反馈信息                out = socket.getOutputStream();                out.write("hello .".getBytes());            } catch (Exception e) {                e.printStackTrace();            } finally {                try {                    out.close();                    in.close();                    socket.close();                    serverSocket.close();                } catch (IOException e) {                    e.printStackTrace();                }            }        }    }}