1 //获取本机的InetAddress实例2 InetAddress address =InetAddress.getLocalHost();3 address.getHostName();//获取计算机名4 address.getHostAddress();//获取IP地址5 byte[] bytes = address.getAddress();//获取字节数组形式的IP地址,以点分隔的四部分6 7 //获取其他主机的InetAddress实例8 InetAddress address2 =InetAddress.getByName("其他主机名");9 InetAddress address3 =InetAddress.getByName("IP地址");

 1 //创建一个URL的实例 2 URL baidu =new URL("http://www.baidu.com"); 3 URL url =new URL(baidu,"/index.html?username=tom#test");//？表示参数，#表示锚点 4 url.getProtocol();//获取协议 5 url.getHost();//获取主机 6 url.getPort();//如果没有指定端口号，根据协议不同使用默认端口。此时getPort()方法的返回值为 -1 7 url.getPath();//获取文件路径 8 url.getFile();//文件名，包括文件路径+参数 9 url.getRef();//相对路径，就是锚点，即#号后面的内容10 url.getQuery();//查询字符串，即参数

package com.yyn.io.net;import java.io.BufferedOutputStream;import java.io.InputStream;import java.io.OutputStream;import java.io.PrintWriter;import java.net.ServerSocket;import java.net.Socket;import java.sql.Date;public class SingleThreadServer extends Thread{ /**  *  单线程的,仅仅是能够应答连接的客户就立即断开连接了     */    private static ServerSocket serverSocket;    public SingleThreadServer(){        super();        try{            serverSocket = new ServerSocket(1112);            System.out.println("SingleThreadSocket creating....");        }catch (Exception e) {            System.out.println("SingleThreadSocket create failed....");            System.exit(1);        }    }        @Override    public void run() {        // TODO Auto-generated method stub        Socket client = null;        while (true) {            if (serverSocket == null) {                return;            }            try{                client = serverSocket.accept();                InputStream in = client.getInputStream();                OutputStream out = client.getOutputStream();                BufferedOutputStream bos = new BufferedOutputStream(out);                PrintWriter writer = new PrintWriter(bos);                Date now = new Date(System.currentTimeMillis());                writer.write(now.toString());                System.out.println("New Connection Accepted:"+client.getRemoteSocketAddress());                writer.flush();                client.close();                            }catch (Exception e) {                // TODO: handle exception            }        }    }        public static void main(String[] args) {        // TODO Auto-generated method stub        SingleThreadServer server = new SingleThreadServer();        server.start();    }}

package com.yyn.io.net;import java.io.BufferedInputStream;import java.io.BufferedOutputStream;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.io.OutputStream;import java.io.PrintWriter;import java.net.ServerSocket;import java.net.Socket;import java.net.UnknownHostException;import java.nio.Buffer;public class SingleThreadClient {    public static void main(String[] args) throws UnknownHostException, IOException {        // TODO Auto-generated method stub        Socket server = new Socket("127.0.0.1", 1112);        OutputStream out = server.getOutputStream();        BufferedOutputStream bos = new BufferedOutputStream(out);        PrintWriter writer = new PrintWriter(bos);        writer.write("Hello server!!!");                InputStream in = server.getInputStream();        InputStreamReader isr = new InputStreamReader(in);        BufferedReader reader = new BufferedReader(isr);        String info = null;        info = reader.readLine();        System.out.println("####Server Message: " + info);        reader.close();        isr.close();        in.close();        writer.close();        bos.close();        out.close();        server.close();            }}

package com.yyn.io.net;import java.io.IOException;import java.net.ServerSocket;import java.net.Socket;//获取用户连接请求，请求成功后，调用MultiThreadSeverThread进行服务public class MultiThreadServerReceiver {    public static final int PORT = 12002;        public static void main(String[] args) throws Exception {        // TODO Auto-generated method stub        init();    }        public static void init() throws Exception{        ServerSocket server = new ServerSocket(PORT);        System.out.println("Server is started");        int count = 0;        while(true){            Socket client = server.accept();            System.out.println("Accepted at: " + client.getRemoteSocketAddress());            MultiThreadSeverThread serverThread = new MultiThreadSeverThread(client);            System.out.println("Start Thread to process!!!");            serverThread.start();            count++;            while (count >=3) {                return;            }        }    }}

package com.yyn.io.net;import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.IOException;import java.io.InputStreamReader;import java.io.OutputStreamWriter;import java.io.PrintWriter;import java.net.Socket;//请求连接后，accept成功后，负责服务的线程类public class MultiThreadSeverThread extends Thread{        private Socket client = null;        private PrintWriter writer = null;        private BufferedReader reader = null;        public static final String CHARSET = "UTF-8";                public MultiThreadSeverThread(Socket client) throws Exception{            this.client = client;            try{                // Init writer                OutputStreamWriter osw = new OutputStreamWriter(client.getOutputStream(),CHARSET);                BufferedWriter bw = new BufferedWriter(osw);                this.writer = new PrintWriter(bw);                                // Init reader                InputStreamReader isr = new InputStreamReader(client.getInputStream(),CHARSET);                this.reader = new BufferedReader(isr);            }catch(Exception e){                e.printStackTrace();                throw new Exception("Init MultiThreadServerThread failed!!!");            }            System.out.println("#######Welcome to server,input commands please!!!");        }        @Override        public void run(){            String command = null;            boolean flag = true;            System.out.println("thread to process!!!");            while (flag) {                try {                    command = this.reader.readLine();                    System.out.println("client command:" + command);                } catch (Exception e) {                    e.printStackTrace();                    flag = false;                }                if (command == null) {                    return ;                }                // if command is not null ,then trim it and change to upper case                command = command.trim().toUpperCase();                if(command.equals("QUIT")){                    flag = false;                }else if (command.equals("HELP")) {                    this.writer.println("本服务器可收到的请求有：");                    this.writer.println("list");                    this.writer.println("push");                    this.writer.println("pop");                }else if(command.equals("LIST") || command.equals("PUSH") || command.equals("POP")) {                    this.writer.println("输入命令正确");                }else{                    this.writer.println("输入命令有误，请重新输入！！！");                }                writer.flush();            }            // close socket connection            try {                this.client.close();            } catch (IOException e) {                // TODO Auto-generated catch block                e.printStackTrace();            }                        }    }

package com.yyn.io.net;import java.io.BufferedOutputStream;import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.FileOutputStream;import java.io.FileWriter;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.io.OutputStream;import java.io.OutputStreamWriter;import java.io.PrintWriter;import java.net.Socket;import java.net.UnknownHostException;import java.util.Iterator;import java.util.stream.Stream;public class MultiThreadServerClient {    public static final int PORT = 12002;        public static void main(String[] args) throws UnknownHostException, IOException {        // TODO Auto-generated method stub        Socket socket = new Socket("127.0.0.1",PORT);        // in stream from console        InputStreamReader isr = new InputStreamReader(System.in,"UTF-8");        BufferedReader in = new BufferedReader(isr);        // out stream from socket        OutputStreamWriter osw =                 new OutputStreamWriter(new BufferedOutputStream(socket.getOutputStream()), "UTF-8");        PrintWriter out = new PrintWriter(osw);        String command = null;        while(true){            System.out.println("#######################");            command = in.readLine();            if (command == null) {                socket.shutdownInput();                break;            }            command = command.trim().toUpperCase();            if (command.equals("EXIT")) {                socket.shutdownInput();                break;            }            out.println(command); //必须用println方法，不能用write，否则服务端无法获取数据，会堵塞            out.flush();                System.out.println("data send to server:"+command);            }    }}