ValidatorUtil.java

package com.verisign.iot.discovery.utils;

import com.verisign.iot.discovery.domain.Fqdn;

/**
 * A collection of static utility methods to deal with parameter validations.
 *
 * @author pmaresca <pmaresca@verisign.com>
 * @version 1.0
 * @since 2015/05/02
 */
public final class ValidatorUtil
{

	public static final String FQDN_PATTERN = "^([(\\\\ )|(\\\\0-9)0-9a-zA-Z_-]+\\.){1,}$";
	public static final String DNS_SD_FQDN_PATTERN = "\\";
	public static final int FQDN_LENGTH = 255;


	/**
	 * Check the input expression.
	 *
	 * @param what A <code>boolean</code> expression to be checked
	 * @throws IllegalArgumentException In case the argument cannot be validated
	 */
	public static void check ( boolean what ) throws IllegalArgumentException
    {
		if ( !what ) {
			throw new IllegalArgumentException( "failed to assert" );
		}
	}


	/**
	 * Validate the Label in Input.
	 *
	 * @param label A <code>String</code> containing a Label
	 * @throws IllegalArgumentException In case the argument cannot be validated
	 */
	public static void isValidLabel ( String label ) throws IllegalArgumentException
    {
		if ( label == null || label.isEmpty() ) {
			throw new IllegalArgumentException( "null/blank label" );
		}
	}


	/**
	 * Validate the Domain Name in Input.
	 *
	 * @param name A <code>Fqdn</code> representing a Domain Name
	 * @throws IllegalArgumentException In case the argument cannot be validated
	 * @see <a href="http://en.wikipedia.org/wiki/Domain_name">Domain Name</a>
	 * @see <a href="http://en.wikipedia.org/wiki/CNAME_record">CNAME</a>
	 */
	public static void isValidDomainName ( Fqdn name ) throws IllegalArgumentException
    {
		if ( name == null ) {
			throw new IllegalArgumentException( "null/blank Fully Qualified Domain Name" );
		}
		else if ( name.fqdn() == null || name.fqdn().isEmpty() ) {
			throw new IllegalArgumentException( "null/blank name" );
		}
		else if ( !name.fqdn().matches( FQDN_PATTERN ) || name.fqdn().length() > FQDN_LENGTH ) {
			throw new IllegalArgumentException( String.format( "invalid FQDN [%s]", name ) );
		}
	}


	/**
	 * Validate the Domain Name in Input.
	 *
	 * @param name A <code>String</code> containing a Domain Name
	 * @throws IllegalArgumentException In case the argument cannot be validated
	 * @see <a href="http://en.wikipedia.org/wiki/Domain_name">Domain Name</a>
	 * @see <a href="http://en.wikipedia.org/wiki/CNAME_record">CNAME</a>
	 */
	public static void isValidDomainName ( String name ) throws IllegalArgumentException
    {
		if ( name == null || name.isEmpty() ) {
			throw new IllegalArgumentException( "null/blank name" );
		}
		else if ( !name.matches( FQDN_PATTERN ) || name.length() > FQDN_LENGTH ) {
			throw new IllegalArgumentException( String.format( "invalid FQDN [%s]", name ) );
		}
	}


	/**
	 * Validate whether the Domain Name is DNS-SD specific or not.
	 *
	 * @param name name A <code>String</code> containing a Domain Name
	 * @return <code>true</code> iff the FQDN is DNS-SD specific
	 */
	public static boolean isDnsSdDomainName ( String name )
    {
		return name.contains( DNS_SD_FQDN_PATTERN );
	}

    public static boolean isValidPort(String portString)
    {
		try{
			int portInt = Integer.parseInt( portString );
			if ( 0 <= portInt && portInt <= 65535 ){
				return true;
			}
		} catch ( NumberFormatException numberFormatException ){
		}
		return false;
	}

	private ValidatorUtil ()
    {
		throw new AssertionError( String.format( "No instances of %s for you!", this.getClass().getName() ) );
	}

}