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//
// Copyright (C) 2006-2016 Talend Inc. - www.talend.com
//
// This source code is available under agreement available at
// %InstallDIR%\features\org.talend.rcp.branding.%PRODUCTNAME%\%PRODUCTNAME%license.txt
//
// You should have received a copy of the agreement
// along with this program; if not, write to Talend SA
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package org.talend.dataquality.email.CommonCheck;

import java.io.Serializable;

/**
 * created by talend on 2014年12月30日 Detailled comment
 *
 */
public class InetAddressValidator implements Serializable {

    private static final long serialVersionUID = -919201640201914789L;

    private static final String IPV4_REGEX = "^(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})$";

    /**
     * Singleton instance of this class.
     */
    private static final InetAddressValidator VALIDATOR = new InetAddressValidator();

    /** IPv4 RegexValidator */
    private final RegexValidator ipv4Validator = new RegexValidator(IPV4_REGEX);

    /**
     * Returns the singleton instance of this validator.
     * 
     * @return the singleton instance of this validator
     */
    public static InetAddressValidator getInstance() {
        return VALIDATOR;
    }

    /**
     * Checks if the specified string is a valid IP address.
     * 
     * @param inetAddress the string to validate
     * @return true if the string validates as an IP address
     */
    public boolean isValid(String inetAddress) {
        return isValidInet4Address(inetAddress);
    }

    /**
     * Validates an IPv4 address. Returns true if valid.
     * 
     * @param inet4Address the IPv4 address to validate
     * @return true if the argument contains a valid IPv4 address
     */
    public boolean isValidInet4Address(String inet4Address) {
        // verify that address conforms to generic IPv4 format
        String[] groups = ipv4Validator.match(inet4Address);

        if (groups == null) {
            return false;
        }

        // verify that address subgroups are legal
        for (int i = 0; i <= 3; i++) {
            String ipSegment = groups[i];
            if (ipSegment == null || ipSegment.length() <= 0) {
                return false;
            }

            int iIpSegment = 0;

            try {
                iIpSegment = Integer.parseInt(ipSegment);
            } catch (NumberFormatException e) {
                return false;
            }

            if (iIpSegment > 255) {
                return false;
            }

        }

        return true;
    }
}