看看下面的代码。除了有效性,它还检查它所属的IP地址类以及它是否是保留的IP地址

Pattern ipPattern;

int[] arr=new int[4];

int i=0;

//Method to check validity

private String validateIpAddress(String ipAddress) {

Matcher ipMatcher=ipPattern.matcher(ipAddress);

//Condition to check input IP format

if(ipMatcher.matches()) {

//Split input IP Address on basis of .

String[] octate=ipAddress.split("[.]");

for(String x:octate) {

//Convert String number into integer

arr[i]=Integer.parseInt(x);

i++;

}

//Check whether input is Class A IP Address or not

if(arr[0]<=127) {

if(arr[0]==0||arr[0]==127)

return(" is Reserved IP Address of Class A");

else if(arr[1]==0&&arr[2]==0&&arr[3]==0)

return(" is Class A Network address");

else if(arr[1]==255&&arr[2]==255&&arr[3]==255)

return( " is Class A Broadcast address");

else

return(" is valid IP Address of Class A");

}

//Check whether input is Class B IP Address or not

else if(arr[0]>=128&&arr[0]<=191) {

if(arr[2]==0&&arr[3]==0)

return(" is Class B Network address");

else if(arr[2]==255&&arr[3]==255)

return(" is Class B Broadcast address");

else

return(" is valid IP Address of Class B");

}

//Check whether input is Class C IP Address or not

else if(arr[0]>=192&&arr[0]<=223) {

if(arr[3]==0)

return(" is Class C Network address");

else if(arr[3]==255)

return(" is Class C Broadcast address");

else

return( " is valid IP Address of Class C");

}

//Check whether input is Class D IP Address or not

else if(arr[0]>=224&&arr[0]<=239) {

return(" is Class D IP Address Reserved for multicasting");

}

//Execute if input is Class E IP Address

else {

return(" is Class E IP Address Reserved for Research and Development by DOD");

}

}

//Input not matched with IP Address pattern

else

return(" is Invalid IP Address");

}

public static void main(String[] args) {

Scanner scan= new Scanner(System.in);

System.out.println("Enter IP Address: ");

//Input IP Address from user

String ipAddress=scan.nextLine();

scan.close();

IPAddress obj=new IPAddress();

//Regex for IP Address

obj.ipPattern=Pattern.compile("((([0-1]?\\d\\d?|2[0-4]\\d|25[0-5])\\.){3}([0-1]?\\d\\d?|2[0-4]\\d|25[0-5]))");

//Display output

System.out.println(ipAddress+ obj.validateIpAddress(ipAddress));

}