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Java实现DNS 使用Java实现DNS域名解析的简单示例

ISH_ICODE 人气:0
想了解使用Java实现DNS域名解析的简单示例的相关内容吗,ISH_ICODE在本文为您仔细讲解Java实现DNS的相关知识和一些Code实例,欢迎阅读和指正,我们先划重点:Java,DNS,下面大家一起来学习吧。

普通的域名解析方法:

import java.net.*; 
 
public class Kkkk { 
 public static void main(String args[]) throws Exception { 
 InetAddress address = InetAddress.getByName("wxh-PC");// wxh-PC是我的计算机名 
 System.out.println(address); 
 System.out.println("-----"); 
 InetAddress address1 = InetAddress.getLocalHost(); 
 System.out.println(address1); 
  
  
 InetAddress[] addresses = InetAddress 
  .getAllByName("www.baidu.com"); 
 System.out.println(addresses.length); 
 for (InetAddress addr : addresses) { 
  System.out.println(addr); 
 } 
 } 
} 

实现具有动态主机IP的域名解析


    目的利用一台INTERNET DNS HOST 将域名定向到家中(个人)的主机上.
  目前CABLEMODEM已经很快了,而且有动态IP,所以就有了将域名解析到个人机器的上可能.
  只要通过很简单的设置就可以搞定.
  
  例如你有一个域名叫 yourdomain.com ,你可以将此域名解析任意的主机.
  
  1.服务器 (IP: A.A.A.A) 启动DNS动态解析的一个小进程.
  jb51.net的域名文件为 /var/named/jb51.net  

        再建个/var/named/jb51.net.static (模板文件可以用来生成jb51.net的)
  
  (JDK1.3 , linux )

  # 原代码如下: ThreadDNSReloadServer.java
  import java.io.*;
  import java.net.*;
  
  public class ThreadDNSReloadServer
  {  public static void main(String[] args)
  { int i=1;
  try
  { ServerSocket s=new ServerSocket(8189);
  for (;;)
  { Socket incoming =s.accept();
  System.out.println("accept new client: " + i);
  new ThreadDNSReloadHandle(incoming,i).start();
  i++ ;
  }
  }
  catch (Exception e)
  { System.out.println(e);
  }
  }
  }
  
  class ThreadDNSReloadHandle extends Thread
  { public ThreadDNSReloadHandle(Socket i,int c)
  { incoming= i; counter=c; }
  
  public void run()
  { try
  { BufferedReader in=new BufferedReader(new InputStreamReader(incoming.getInputStream()));
  
  String User="Unkown";
  String DNSFILEPATH="/var/named/";
  String DNSFILE="jb51.net";
  String HOSTIP="127.0.0.1";
  boolean USER_VALIDATED=true ;
  boolean done=false;
  
  while ( !done )
  {  String str=in.readLine();
  //validate user;
  if ( str ==null ) done=true;
  else
  {
  str=str.trim();
  if ( str.substring(0,2).equals("LA") )
  { if (str.length() >2) User=str.substring(2);
  }
  if ( str.substring(0,2).equals("LB") )
  { if (str.length() >2) DNSFILE=str.substring(2);
  }
  if ( str.substring(0,2).equals("LC") )
  { if (str.length() >2) HOSTIP=str.substring(2);
  }
  
  if ( str.trim().equals("BYE")) done = true;
  }
  
  }
  incoming.close();
  //加入用户验证.
  //将服务器中的jb51.net.static文件写入jb51.net中
  String DNSTMP =DNSFILEPATH + DNSFILE +".static";
  BufferedReader sin=new BufferedReader(new FileReader(DNSTMP));
  PrintWriter sout=new PrintWriter(new FileWriter(DNSFILEPATH + DNSFILE) , true);
  String s;
  while ((s=sin.readLine()) != null)
  {
  if (s.startsWith("host"))
  { s="host IN A " + HOSTIP;
  sout.println(s);
  s="@ IN A " + HOSTIP;
  }
  sout.println(s);
  }
  //System.out.println("User:" + User );
  //System.out.println("DNSFILE:" + DNSFILE );
  //System.out.println("HOSTIP:" + HOSTIP );
  
  //ndc reload
  String command="ndc reload " + DNSFILE ;
  java.lang.Runtime.getRuntime().exec(command);
  
  }
  catch ( Exception e)
  { System.out.println(e);
  }
  }
  
  private Socket incoming;
  private int counter;
  
  }

  
  2.客户机(windows / linux)
  

# 客户端每次启动时加入到开机启动(或进程中): SockTest.java
  import java.io.*;
  import java.net.*;
  
  public class SocketTest
  { public static void main(String[] args)
  { try
  { Socket s=new Socket("A.A.A.A",8189);
  BufferedReader in=new BufferedReader(new InputStreamReader(s.getInputStream()));
  PrintWriter out=new PrintWriter(s.getOutputStream(),true);
  
  InetAddress localHostAddress =InetAddress.getLocalHost() ; //get LocalHost Ip
  out.println("LAguest");
  out.println("LByourdomain.com");
  out.println("LC" + localHostAddress.getHostAddress() );
  
  out.close();
  s.close();
  
  }
  catch (IOException e)
  { System.out.println(e);
  }
  }
  }

  dns 样本文件: ( jb51.net.static)

  @ ns.dnsserver.com xxxxx
  xxxx
  host    IN A 127.0.0.1      // 此处就是要更改的地方
  www    IN CNAME host
  ...

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