Java IP Address Mash checkIpMask(String ip)

Description

check Ip Mask

License

Open Source License

Declaration

public static String checkIpMask(String ip) 

Method Source Code

//package com.java2s;
//License from project: Open Source License 

public class Main {
    public static String checkIpMask(String ip) {
        String ipParts[] = ip.split("\\.");
        if (ipParts.length != 4)
            return "IP address must have 4 parts";
        String message = checkIpMaskPart(ipParts[0]);
        if (message != null)
            return message;
        message = checkIpMaskPart(ipParts[1]);
        if (message != null)
            return message;
        message = checkIpMaskPart(ipParts[2]);
        if (message != null)
            return message;
        message = checkIpMaskPart(ipParts[3]);
        if (message != null)
            return message;
        else//from  w w w  .  j ava 2s. c  om
            return null;
    }

    private static String checkIpMaskPart(String part) {
        int dash;
        if ("*".equals(part))
            return null;
        dash = part.indexOf('-');
        if (dash == -1) {
            int value = Integer.parseInt(part);
            if (value < 0 || value > 255)
                return (new StringBuilder()).append("Value out of range in '").append(part).append("'").toString();
            //break MISSING_BLOCK_LABEL_219;
        }
        int from;
        from = Integer.parseInt(part.substring(0, dash));
        if (from < 0 || from > 255)
            return (new StringBuilder()).append("'From' value out of range in '").append(part).append("'")
                    .toString();
        int to;
        try {
            to = Integer.parseInt(part.substring(dash + 1));
            if (to < 0 || to > 255)
                return (new StringBuilder()).append("'To' value out of range in '").append(part).append("'")
                        .toString();
        } catch (NumberFormatException e) {
            return (new StringBuilder()).append("Integer parsing error in '").append(part).append("'").toString();
        }
        if (from > to)
            return (new StringBuilder()).append("'From' value is greater than 'To' value in '").append(part)
                    .append("'").toString();
        return null;
    }
}

Related

1. checkIpMaskPart(String part)
2. checkIpMaskPart(String part)