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[java] String to long[] and back

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Hi, I'm looking to convert a String to an array of longs and back again. The following code has been tried, but doesnt work correctly.
public static String longToString( long[] source )
        {
            byte[] bytes = new byte[ source.length * 8 ];
            int b = 0;
            for ( int i = 0; i < source.length; i++, b += 8 )
            {
                bytes[ b ] = (byte)( source[ i ] & 0xFF );
                bytes[ b + 1 ] = (byte)( ( source[ i ] >> 8 ) & 0xFF );
                bytes[ b + 2 ] = (byte)( ( source[ i ] >> 16 ) & 0xFF );
                bytes[ b + 3 ] = (byte)( ( source[ i ] >> 24 ) & 0xFF );
                bytes[ b + 4 ] = (byte)( ( source[ i ] >> 32 ) & 0xFF );
                bytes[ b + 5 ] = (byte)( ( source[ i ] >> 40 ) & 0xFF );
                bytes[ b + 6 ] = (byte)( ( source[ i ] >> 48 ) & 0xFF );
                bytes[ b + 7 ] = (byte)( ( source[ i ] >> 56 ) & 0xFF );
            }
            
            return new String( bytes );
        }
        
        public static long[] stringToLong( String str )
        {
            int needsPadding = 8 - ( str.length() % 8 );
            
            while ( needsPadding > 0 )
            {
                //System.out.println( "adding padding:" + needsPadding );
                needsPadding--;
                str += ' ';
            }
            
            byte[] bytes = str.getBytes();
            int lengthInLong = bytes.length / 8; 
            long[] ret = new long[ lengthInLong ];
           
            int b = 0;
            
            System.out.println( "length:"+lengthInLong+" str:'"+str+"' bytes length:"+ bytes.length+" strlength:"+str.length() );
            for ( int i = 0; i < lengthInLong; i++, b+= 8 )
            {
                System.out.println( "i:"+i);
                ret[ i ] = bytes[ b ] + ( bytes[ b + 1 ] << 8 ) + ( bytes[ b + 2 ] << 16 ) + ( bytes[ b + 3 ] << 24 ) + ( bytes[ b + 4 ] << 32 ) 
                            + ( bytes[ b + 5 ] << 40 ) + ( bytes[ b + 6 ] << 48 ) + ( bytes[ b + 7 ] << 56 );
            }
            
            return ret;
        }  
Also, ive used a different way of doing things, however this doesnt work correctly when some of the longs become negative (due to encryption and the like).
        /**
         * Converts an array of longs into a string
         *
         * @param source The long's to convert into a string
         *
         * @return The longs in string form
         */
        public static String longToString( long[] source )
        {
            StringBuffer ret = new StringBuffer();
            for ( int i = 0; i < source.length; i++ )
            {
                ret.append( (char)( source[ i ] & 0xFF ) );
                ret.append( (char)( ( source[ i ] >>> 8 ) & 0xFF ) );
                ret.append( (char)( ( source[ i ] >>> 16 ) & 0xFF ) );
                ret.append( (char)( ( source[ i ] >>> 24 ) & 0xFF ) );
            }
            
            return ret.toString();
        }
        
        /**
         * Converts a string into an array of longs
         *
         * @param str The string to be converted
         *
         * @return An array of longs created from the string.
         */
        public static long[] stringToLong( String str )
        {
            int needsPadding = str.length() % 4;
            while ( needsPadding > 0 )
            {
                needsPadding--;
                str += ' ';
            }
            int lengthInLong = str.length() / 4;
            long[] ret = new long[ lengthInLong ];
            
            for ( int i = 0; i < lengthInLong; i++ )
            {
                ret[ i ] = str.charAt( i << 2 ) + ( str.charAt( (i << 2) + 1 ) << 8 ) + ( str.charAt( (i << 2) + 2 ) << 16 ) + ( str.charAt( (i << 2) + 3 ) << 24 );
            }
            
            return ret;
        }

Any help, or suggestions on how to do this would be greatly appreciated! Thanks in advance.

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What exactly are you trying to do? Give an example of some input and output expected.

If you're trying to do what i'm thinking, I see no need for all that code.

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