用Java编写简单的UDP网络通信程序

Java中封装了大量的socket API 为编写网络通信程序提供了极大的方便 在计算机网络的学习中 大家都已熟练掌握了TCP/UDP的基本原理 在此不在赘述 仅给出接收端和发送端的源代码 供大家讨论学习 发送端代码祥闷绝如下:import java io *import java lang *import *public class uclient谨姿{private DatagramSocket cliprivate DatagramPacket pacprivate byte *** []private String senpublic uclient(){Init()}public void Init(){try{//指定端口号 避免与其他应用程序发生冲突cli=new DatagramSocket( )*** =new byte[ ]sen= UDP方式发送数据 *** =sen getBytes()pac=new DatagramPacket( *** *** length InetAddress getByName( localhost ) )cli send(pac)}catch(SocketException se){se printStackTrace()}catch(IOException ie){ie printStackTrace()}}public static void main(String args[]){new uclient()}}接收端数据:import java io *import java lang *import *public class userve{private DatagramSocket serprivate DatagramPacket pacprivate byte rb[]private String revpublic userve(){Init()}public void Init()罩庆{try{ser=new DatagramSocket( )rb=new byte[ ]pac=new DatagramPacket(rb rb length)rev= int i= while(i== )//无数据 则循环{ser receive(pac)i=pac getLength()//接收数据if(i>){//指定接收到数据的长度 可使接收数据正常显示 开始时很容易忽略这一点rev=new String(rb pac getLength())System out println(rev)i= //循环接收}}}catch(Exception e){e printStackTrace()}}public static void main(String args[]){new userve()}} lishixinzhi/Article/program/Java/hx/201311/26023

以前写的，照贴了。。。服务器端：import java.awt.*\x0d\x0aimport java.awt.event.WindowAdapter\x0d\x0aimport java.awt.event.WindowEvent\x0d\x0aimport java.io.*\x0d\x0aimport java.net.*/*6、 采用UDP协兄侍议，编写一羡销吵个Java网络应用程序，该应用分服务器端程序和客户端程序两部分。\x0d\x0a* 客户端指定一个服务器上的文件名，让服斗梁务器发回该文件的内容，或者提示文件不存在。\x0d\x0a* （20分）（服务端程序和客户端程序分别命名为Server.java和Client.java）*/\x0d\x0apublic class N4BT6 extends Frame\x0d\x0a{\x0d\x0aDatagramSocket socket \x0d\x0aDatagramPacket packet byte[] buf \x0d\x0aFile file \x0d\x0aFileInputStream input\x0d\x0aString message = "该文件不存在"\x0d\x0aTextArea text\x0d\x0apublic N4BT6(String title)\x0d\x0a{\x0d\x0asuper(title)\x0d\x0atext = new TextArea(6,4)\x0d\x0aadd(text)\x0d\x0asetSize(400, 300)\x0d\x0asetVisible(true)\x0d\x0aaddWindowListener(new WindowAdapter()\x0d\x0a{\x0d\x0apublic void windowClosing(WindowEvent e)\x0d\x0a{\x0d\x0adispose()\x0d\x0a}\x0d\x0a})\x0d\x0a\x0d\x0abuf = new byte[1024]\x0d\x0atry\x0d\x0a{\x0d\x0asocket = new DatagramSocket(1230)\x0d\x0apacket = new DatagramPacket(buf, buf.length)\x0d\x0asocket.receive(packet)\x0d\x0afile = new File(new String(packet.getData()))\x0d\x0asocket = new DatagramSocket()\x0d\x0a} \x0d\x0acatch (Exception e)\x0d\x0a{e.printStackTrace()\x0d\x0a}\x0d\x0a\x0d\x0aif(file.exists())\x0d\x0a{\x0d\x0atry\x0d\x0a{\x0d\x0abuf = new byte[(int)file.length()]\x0d\x0apacket = new DatagramPacket(buf,buf.length,InetAddress.getLocalHost(),1234)\x0d\x0ainput = new FileInputStream(file)\x0d\x0ainput.read(buf)\x0d\x0asocket.send(packet)\x0d\x0a}\x0d\x0acatch (IOException e) \x0d\x0a{\x0d\x0ae.printStackTrace()\x0d\x0a}\x0d\x0a}\x0d\x0aelse\x0d\x0a{\x0d\x0atry\x0d\x0a{\x0d\x0apacket = new DatagramPacket(message.getBytes(),message.getBytes().length,\x0d\x0aInetAddress.getLocalHost(),1234)\x0d\x0asocket.send(packet)\x0d\x0a}\x0d\x0acatch (Exception e) \x0d\x0a{\x0d\x0ae.printStackTrace()\x0d\x0a}\x0d\x0a}\x0d\x0a\x0d\x0a}\x0d\x0apublic static void main(String[] args)\x0d\x0a{\x0d\x0anew N4BT6("Server")\x0d\x0a}\x0d\x0a}\x0d\x0a客户端：import java.awt.*\x0d\x0aimport java.awt.event.*\x0d\x0aimport java.net.DatagramPacket\x0d\x0aimport java.net.DatagramSocket\x0d\x0aimport java.net.InetAddresspublic class N4BT6_2 extends Frame\x0d\x0a{\x0d\x0aTextArea text\x0d\x0aString message = "Q.txt"\x0d\x0aDatagramSocket socket \x0d\x0aDatagramPacket packet\x0d\x0abyte[] buf\x0d\x0apublic N4BT6_2(String title)\x0d\x0a{\x0d\x0asuper(title)\x0d\x0atext = new TextArea(6,4)\x0d\x0aadd(text)\x0d\x0asetSize(400, 300)\x0d\x0asetVisible(true)\x0d\x0aaddWindowListener(new WindowAdapter()\x0d\x0a{\x0d\x0apublic void windowClosing(WindowEvent e)\x0d\x0a{\x0d\x0adispose()\x0d\x0a}\x0d\x0a})\x0d\x0atry\x0d\x0a{\x0d\x0a\x0d\x0asocket = new DatagramSocket()\x0d\x0apacket = new DatagramPacket(message.getBytes(),message.getBytes().length,\x0d\x0aInetAddress.getLocalHost(),1230)\x0d\x0asocket.send(packet)\x0d\x0a}\x0d\x0acatch (Exception e) \x0d\x0a{\x0d\x0ae.printStackTrace()\x0d\x0a}\x0d\x0a\x0d\x0atry\x0d\x0a{\x0d\x0abuf = new byte[1024]\x0d\x0asocket = new DatagramSocket(1234)\x0d\x0apacket = new DatagramPacket(buf,buf.length)\x0d\x0asocket.receive(packet)\x0d\x0atext.append(new String(buf))\x0d\x0a}\x0d\x0acatch (Exception e) \x0d\x0a{\x0d\x0ae.printStackTrace()\x0d\x0a}\x0d\x0a}\x0d\x0apublic static void main(String[] args)\x0d\x0a{\x0d\x0anew N4BT6_2("Client")\x0d\x0a}\x0d\x0a}

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