question: public static String replace ( String source , String target , String replacement ) { StringBuffer output = new StringBuffer ( ) ; int n = 0 ; while ( true ) { int off = source . indexOf ( target , n ) ; if ( off == - 1 ) { output . append ( source . substring ( n ) ) ; break ; } output . append ( source . substring ( n , off ) ) ; output . append ( replacement ) ; n = off + target . length ( ) ; } return output . toString ( ) ; }
target:  Description of the Method