org.cyclopsgroup.caff.util.UUIDUtils Maven / Gradle / Ivy

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package org.cyclopsgroup.caff.util;

import java.util.UUID;

import org.apache.commons.codec.binary.Base64;

/**
 * Utilities around {@link UUID}
 *
 * @author Jiaqi Guo
 */
public final class UUIDUtils
{
    /**
     * Convert byte array into UUID. Byte array is a compact form of bits in UUID
     *
     * @param bytes Byte array to convert from
     * @return UUID result
     */
    public static UUID fromBytes( byte[] bytes )
    {
        long mostBits = ByteUtils.readLong( bytes, 0 );
        long leastBits = 0;
        if ( bytes.length > 8 )
        {
            leastBits = ByteUtils.readLong( bytes, 8 );
        }
        return new UUID( mostBits, leastBits );
    };

    /**
     * Convert string into UUID. String is a compact base64 form of bits in UUID
     *
     * @param id String expression of UUID
     * @return UUID result
     */
    public static UUID fromString( String id )
    {
        return fromBytes( Base64.decodeBase64( id ) );
    }

    /**
     * Convert UUID in compact form of byte array
     *
     * @param id UUID to convert from
     * @return Byte array result
     */
    public static byte[] toBytes( UUID id )
    {
        byte[] bytes = new byte[16];
        ByteUtils.writeLong( id.getMostSignificantBits(), bytes, 0 );
        ByteUtils.writeLong( id.getLeastSignificantBits(), bytes, 8 );
        return bytes;
    }

    /**
     * Convert UUID into form of base64 string without = and +
     *
     * @param id UUID to convert from
     * @return String result
     */
    public static String toString( UUID id )
    {
        return Base64.encodeBase64URLSafeString( toBytes( id ) );
    }

    /**
     * Generate a random UUID and return as a base 64 string
     *
     * @return Base 64 string form of a random UUID generated from {@link UUID#randomUUID()}
     */
    public static String randomStringId()
    {
        return toString( UUID.randomUUID() );
    }

    private UUIDUtils()
    {
    }
}