1.URL

import java.io.BufferedReader;

import java.io.BufferedWriter;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.OutputStreamWriter;

import java.net.URL;

public class Test_URL {

public static void main(String[] args) throws IOException, InterruptedException {

URL url = new URL("");

System.out.println("URL："+url.toString()+"\n"

+"协议："+url.getProtocol()+"\n"

+"域名："+url.getHost()+"\n"

+"端口："+(url.getPort()==-1? 80:url.getPort())+"\n"

+"资源："+url.getFile()+"\n"

+"锚点："+url.getRef()+"\n"

+"参数："+url.getQuery()+"\n" //若锚点存在，则返回null

+"相对路径："+url.getPath());

Thread.sleep(3000);

BufferedReader br =new BufferedReader(new InputStreamReader(url.openStream(), "UTF-8"));

BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("test/www.html"), "UTF-8"));

String msg = null;

while(null!=(msg=br.readLine())){

System.out.println(msg);

bw.append(msg);

bw.newLine();

}

bw.flush();

bw.close();

br.close();

}

}

2.UDP

import java.io.IOException;

import java.net.DatagramPacket;

import java.net.DatagramSocket;

import java.net.InetSocketAddress;

public class Test_UDP {

public static class Server implements Runnable {        public void run() {        try {            DatagramSocket server;            server = new DatagramSocket(3333);            byte[] container = new byte[1024];            DatagramPacket packet = new DatagramPacket(container, container.length);            server.receive(packet);            byte[] data = packet.getData();            int len = packet.getLength();            System.out.println("服务器已接受信息");            Thread.sleep(800);            System.out.println("信息："+new String(data, 0, len));            server.close();        } catch (IOException e) {            e.printStackTrace();        } catch (InterruptedException e) {            e.printStackTrace();        }    }}public static class Client implements Runnable {        public void run() {        try {            DatagramSocket client  = new DatagramSocket(5555);            String msg = "udp测试成功！";            byte[] data = msg.getBytes();            DatagramPacket packet = new DatagramPacket(data, data.length, new InetSocketAddress("myLaptop", 3333));            client.send(packet);            client.close();        } catch (IOException e) {            e.printStackTrace();        }    }}public static void main(String[] args) throws IOException, InterruptedException {       new Thread(new Server()).start();    System.out.println("服务器接收就绪");    Thread.sleep(1600);    System.out.print("客户端正在发送信息");    for(int i=0; i<3; i++){        Thread.sleep(400);        System.out.print(".");    }    System.out.println();    Thread.sleep(1200);    new Thread(new Client()).start();}

}