java基础复习总结6

常见URL 并使用

public class Url1{public static void main(String[] args) throws Exception{URL url = new URL("http://java.sun.com:80/docs/books/tutorial/index.html#DOWN");String protocol = url.getProtocol();String host = url.getHost();String file = url.getFile();int port = url.getPort();String ref = url.getRef();System.out.println(protocol + ", " + host + ", " + file + ", " + port+ ", " + ref);}}

?用url建立链接

public class UrlConnection1{public static void main(String[] args) throws Exception{URL url = new URL("http://www.infoq.com");URLConnection conn = url.openConnection();InputStream is = conn.getInputStream();OutputStream os = new FileOutputStream("c:\\infoq.txt");byte[] buffer = new byte[2048];int length = 0;while(-1 != (length = is.read(buffer, 0, buffer.length))){os.write(buffer, 0, length);}is.close();os.close();}}

??server

import java.io.InputStream;import java.io.OutputStream;import java.net.ServerSocket;import java.net.Socket;public class TcpServer{public static void main(String[] args) throws Exception{ServerSocket ss = new ServerSocket(5000);Socket socket = ss.accept();InputStream is = socket.getInputStream();OutputStream os = socket.getOutputStream();byte[] buffer = new byte[200];int length = is.read(buffer);System.out.println(new String(buffer, 0 ,length));//int length = 0;//while(-1 != (length = is.read(buffer,0, buffer.length)))//{//String str = new String(buffer, 0, length);////System.out.println(str);//}os.write("welcome".getBytes());is.close();os.close();socket.close();}}

?

client

?

import java.io.InputStream;import java.io.OutputStream;import java.net.Socket;public class TcpClient{ public static void main(String[] args) throws Exception {  Socket socket = new Socket("127.0.0.1", 5000);    InputStream is = socket.getInputStream();    OutputStream os = socket.getOutputStream();    os.write("hello world".getBytes());    byte[] buffer = new byte[200];    int length = is.read(buffer);    System.out.println(new String(buffer, 0 ,length));  //  int length = 0;//  //  while(-1 != (length = is.read(buffer,0, buffer.length)))//  {//   String str = new String(buffer, 0, length);//   //   System.out.println(str);//  }    is.close();  os.close();  socket.close(); }}

?

udp

?

import java.net.DatagramPacket;import java.net.DatagramSocket;import java.net.InetAddress;public class UdpTest1{public static void main(String[] args) throws Exception{DatagramSocket socket = new DatagramSocket();String str = "hello world";DatagramPacket packet = new DatagramPacket(str.getBytes(),str.length(), InetAddress.getByName("localhost"), 7000);socket.send(packet);byte[] buffer = new byte[1000];DatagramPacket packet2 = new DatagramPacket(buffer,100);socket.receive(packet2);System.out.println(new String(buffer, 0, packet2.getLength()));socket.close();}}

udp

import java.net.DatagramPacket;import java.net.DatagramSocket;public class UdpTest2{ public static void main(String[] args) throws Exception{DatagramSocket socket = new DatagramSocket(7000);byte[] buffer = new byte[1000];DatagramPacket packet = new DatagramPacket(buffer, 1000);socket.receive(packet);System.out.println(new String(buffer, 0, packet.getLength()));String str = "welcome";DatagramPacket packet2 = new DatagramPacket(str.getBytes(),str.length(), packet.getAddress(), packet.getPort());socket.send(packet2);socket.close();}}

??