[Java>Original]Useful Network Utility(Utility to check Netmask, Network address)

Useful Network Utility to calculate CIDR address and check network address.

References

• about CIDR
  http://h50146.www5.hp.com/products/software/oe/tru64unix/manual/v51a_ref/HTML/MAN/MAN7/0127____.HTM
• Sample Source code
  http://osdir.com/ml/jakarta.james.devel/2003-02/msg00469.html
  http://lenya.apache.org/apidocs/1.2/org/apache/lenya/net/InetAddressUtil.html
  

Original Source Code

• http://groups.google.com/group/taapps-sourcecode-libraries/web/Net.java
  

Check Utility to contain the ip address into the specified CIDR network address.

• Description
  Network address check utility
  Check whether the specified ip address is into the CIDR network address(format like "192.168.1.0/24") or not.
  This method has 2 arguments, one is String object contains CIDR network address, other is IP address you want to check.
  
• Sample
  

  //for example, my ip address is 192.168.1.3
  //check whether my ip address "192.168.1.3" is into the network 192.168.1.0/24 or not
  boolean compare=Net.containIp("192.168.1.0/24","192.168.1.3");
  if(compare){
  //contain the specified ip address "192.168.1.3" into network "192.168.1.0/24"
  }
  

Check Utility 2 to contain the ip address into the specified CIDR network list.

• Description
  Check whether the specified ip address is into the CIDR network address list or not.
  This method has 2 arguments, one is List object contains CIDR network addresses, other is IP address you want to check.
  
• Sample
  

  List networkList=new ArrayList();
  networkList.add("192.168.1.0/24");
  networkList.add("192.168.2.0/24");
  networkList.add("192.168.3.0/24");
  networkList.add("192.168.4.0/24");
  boolean compare2=Net.containIp(networkList,"192.168.2.200");
  if(compare){
  //contain the specified ip address "192.168.1.3" into network "192.168.1.0/24"
  }