stringtools.java

java base64

                }// end if
            }// end for
        if ( changed )
            {
            s = new String( ca );
            }
        return s;
        }// end toBookTitleCase

    /**
     * Convert int to hex with lead zeroes
     *
     * @param h number you want to convert to hex
     * @return 0x followed by unsigned hex 8-digit representation
     * @noinspection WeakerAccess
     * @see #toString(Color)
     */
    public static String toHexString( int h )
        {
        String s = Integer.toHexString( h );
        if ( s.length() < 8 )
            {// pad on left with zeros
            s = "00000000".substring( 0, 8 - s.length() ) + s;
            }
        return "0x" + s;
        }

    /**
     * Convert an integer to a String, with left zeroes.
     *
     * @param i   the integer to be converted
     * @param len the length of the resulting string. Warning. It will chop the result on the left if it is too long.
     * @return String representation of the int e.g. 007
     */
    public static String toLZ( int i, int len )
        {
        // Since String is final, we could not add this method there.
        String s = Integer.toString( i );
        if ( s.length() > len )
            {/* return rightmost len chars */
            return s.substring( s.length() - len );
            }
        else if ( s.length() < len )
            // pad on left with zeros
            {
            return "000000000000000000000000000000".substring( 0, len - s.length() ) + s;
            }
        else
            {
            return s;
            }
        }// end toLZ

    /**
     * Quick replacement for Character.toLowerCase for use with English-only. It does not deal with accented
     * characters.
     *
     * @param c character to convert
     * @return character converted to lower case
     */
    public static char toLowerCase( char c )
        {
        return 'A' <= c && c <= 'Z' ? ( char ) ( c + ( 'a' - 'A' ) ) : c;
        }

    /**
     * Quick replacement for Character.toLowerCase for use with English-only. It does not deal with accented
     * characters.
     *
     * @param s String to convert
     * @return String converted to lower case
     */
    public static String toLowerCase( String s )
        {
        final char[] ca = s.toCharArray();
        final int length = ca.length;
        boolean changed = false;
        // can't use for:each since we need the index to set.
        for ( int i = 0; i < length; i++ )
            {
            final char c = ca[ i ];
            if ( 'A' <= c && c <= 'Z' )
                {
                // found a char that needs conversion.
                ca[ i ] = ( char ) ( c + ( 'a' - 'A' ) );
                changed = true;
                }
            }
        // give back same string if unchanged.
        return changed ? new String( ca ) : s;
        }

    /**
     * convert an integer value to unsigned hex with leading zeroes.
     *
     * @param value integer to convert.
     * @param len   how many characters you want in the result.
     */
    public static String toLzHexString( int value, int len )
        {
        // Since String is final, we could not add this method there.
        final String s = Integer.toHexString( value );
        if ( s.length() > len )
            {/* return rightmost len chars */
            return s.substring( s.length() - len );
            }
        else if ( s.length() < len )
            // pad on left with zeros.  at most 7 will be prepended
            {
            return "0000000".substring( 0, len - s.length() ) + s;
            }
        else
            {
            return s;
            }
        }

    /**
     * Get #ffffff html hex number for a colour
     *
     * @param c Color object whose html colour number you want as a string
     * @return # followed by 6 hex digits
     * @noinspection WeakerAccess,SameParameterValue
     * @see #toHexString(int)
     */
    public static String toString( Color c )
        {
        String s = Integer.toHexString( c.getRGB() & 0xffffff );
        if ( s.length() < 6 )
            {// pad on left with zeros
            s = "000000".substring( 0, 6 - s.length() ) + s;
            }
        return '#' + s;
        }

    /**
     * Quick replacement for Character.toUpperCase for use with English-only. It does not deal with accented
     * characters.
     *
     * @param c character to convert
     * @return character converted to upper case
     */
    public static char toUpperCase( char c )
        {
        return 'a' <= c && c <= 'z' ? ( char ) ( c + ( 'A' - 'a' ) ) : c;
        }

    /**
     * Quick replacement for Character.toUpperCase for use with English-only. It does not deal with accented
     * characters.
     *
     * @param s String to convert
     * @return String converted to upper case
     */
    public static String toUpperCase( String s )
        {
        final char[] ca = s.toCharArray();
        final int length = ca.length;
        boolean changed = false;
        // can't use for:each since we need the index to set.
        for ( int i = 0; i < length; i++ )
            {
            final char c = ca[ i ];
            if ( 'a' <= c && c <= 'z' )
                {
                // found a char that needs conversion.
                ca[ i ] = ( char ) ( c + ( 'A' - 'a' ) );
                changed = true;
                }
            }
        // give back same string if unchanged.
        return changed ? new String( ca ) : s;
        }

    /**
     * Removes white space from beginning this string.
     *
     * @param s String to process. As always the original in unchanged.
     * @return this string, with leading white space removed
     * @noinspection WeakerAccess,WeakerAccess,WeakerAccess,SameParameterValue,WeakerAccess
     * @see #trimLeading(String,char)
     *      <p/>
     *      All characters that have codes less than or equal to <code>'&#92;u0020'</code> (the space character) are
     *      considered to be white space.
     */
    public static String trimLeading( String s )
        {
        if ( s == null )
            {
            return null;
            }
        int len = s.length();
        int st = 0;
        while ( ( st < len ) && ( s.charAt( st ) <= ' ' ) )
            {
            st++;
            }
        return ( st > 0 ) ? s.substring( st, len ) : s;
        }// end trimLeading

    /**
     * trim leading characters there are on a string matching a given character.
     *
     * @param text text with possible trailing characters, possibly empty, but not null.
     * @param c    the trailing character of interest, usually ' ' or '\n'
     * @return string with any of those trailing characters removed.
     * @see #trimLeading(String)
     */
    public static String trimLeading( String text, char c )
        {
        int count = countLeading( text, c );
        // substring will optimise the 0 case.
        return text.substring( count );
        }

    /**
     * Removes white space from end this string.
     *
     * @param s String to process. As always the original in unchanged.
     * @return this string, with trailing white space removed
     * @see #trimTrailing(String,char)
     *      <p/>
     *      All characters that have codes less than or equal to <code>'&#92;u0020'</code> (the space character) are
     *      considered to be white space.
     */
    public static String trimTrailing( String s )
        {
        if ( s == null )
            {
            return null;
            }
        int len = s.length();
        int origLen = len;
        while ( ( len > 0 ) && ( s.charAt( len - 1 ) <= ' ' ) )
            {
            len--;
            }
        return ( len != origLen ) ? s.substring( 0, len ) : s;
        }// end trimTrailing

    /**
     * trim trailing characters there are on a string matching a given character.
     *
     * @param text text with possible trailing characters, possibly empty, but not null.
     * @param c    the trailing character of interest, usually ' ' or '\n'
     * @return string with any of those trailing characters removed.
     * @see #trimTrailing(String)
     */
    public static String trimTrailing( String text, char c )
        {
        int count = countTrailing( text, c );
        // substring will optimise the 0 case.
        return text.substring( 0, text.length() - count );
        }

    // --------------------------- CONSTRUCTORS ---------------------------

    /**
     * StringTools contains only static methods.
     */
    private StringTools()
        {

        }

    // --------------------------- main() method ---------------------------

    /**
     * Test harness, used in debugging
     *
     * @param args not used
     */
    public static void main( String[] args )
        {
        if ( DEBUGGING )
            {
            System.out.println( condense( "   this  is   spaced.  " ) );
            System.out.println( trimLeading( "   trim   " ) );
            System.out.println( trimTrailing( "   trim   " ) );

            System.out.println( trimLeading( "*****t*r*i*m****", '*' ) );
            System.out.println( trimTrailing( "*****t*r*i*m****", '*' ) );

            System.out.println( toString( Color.red ) );
            System.out.println( toHexString( -3 ) );
            System.out.println( toHexString( 3 ) );
            System.out.println( countLeading( "none", ' ' ) );
            System.out.println( countLeading( "*one***", '*' ) );
            System.out.println( countLeading( "\n\ntw\n\n\no\n\n\n\n", '\n' ) );
            System.out.println( countTrailing( "none", ' ' ) );
            System.out.println( countTrailing( "***one*", '*' ) );
            System.out
                    .println( countTrailing( "\n\n\n\nt\n\n\n\nwo\n\n",
                            '\n' ) );

            System.out.println( quoteSQL( "Judy's Place" ) );
            System.out.println( parseLongPennies( "$5.00" ) );
            System.out.println( parseLongPennies( "$50" ) );
            System.out.println( parseLongPennies( "50" ) );
            System.out.println( parseLongPennies( "$50-" ) );

            System.out.println( penniesToString( 0 ) );
            System.out.println( penniesToString( -1 ) );
            System.out.println( penniesToString( 20 ) );
            System.out.println( penniesToString( 302 ) );
            System.out.println( penniesToString( -100000 ) );
            System.out
                    .println( toBookTitleCase(
                            "handbook to HIGHER consciousness" ) );
            System.out
                    .println( toBookTitleCase( "THE HISTORY OF THE U.S.A." ) );
            System.out.println( toBookTitleCase( "THE HISTORY OF THE USA" ) );

            System.out.println( rightPad( "abc", 6, true ) + "*" );
            System.out.println( rightPad( "abc", 2, true ) + "*" );
            System.out.println( rightPad( "abc", 2, false ) + "*" );
            System.out.println( rightPad( "abc", 3, true ) + "*" );
            System.out.println( rightPad( "abc", 3, false ) + "*" );
            System.out.println( rightPad( "abc", 0, true ) + "*" );
            System.out.println( rightPad( "abc", 20, true ) + "*" );
            System.out.println( rightPad( "abc", 29, true ) + "*" );
            System.out.println( rightPad( "abc", 30, true ) + "*" );
            System.out.println( rightPad( "abc", 31, true ) + "*" );
            System.out.println( rightPad( "abc", 40, true ) + "*" );

            System.out.println( toUpperCase( 'q' ) );
            System.out.println( toUpperCase( 'Q' ) );
            System.out
                    .println( toUpperCase(
                            "The quick brown fox was 10 feet tall." ) );
            System.out
                    .println( toUpperCase(
                            "THE QUICK BROWN FOX WAS 10 FEET TALL." ) );
            System.out
                    .println( toUpperCase(
                            "the quick brown fox was 10 feet tall." ) );
            System.out.println( toLowerCase( 'q' ) );
            System.out.println( toLowerCase( 'Q' ) );
            System.out
                    .println( toLowerCase(
                            "The quick brown fox was 10 feet tall." ) );
            System.out
                    .println( toLowerCase(
                            "THE QUICK BROWN FOX WAS 10 FEET TALL." ) );
            System.out
                    .println( toLowerCase(
                            "the quick brown fox was 10 feet tall." ) );

            System.out.println( "count instances should be 4: " + countInstances( " abab abcdefgab", "ab" ) );
            }
        }// end main
    }