question: public void findPackageAndClass ( ) throws IOException { packageName = null ; className = null ; LineNumberReader reader = new LineNumberReader ( new FileReader ( inputFile ) ) ; while ( className == null || packageName == null ) { String line = reader . readLine ( ) ; if ( line == null ) break ; if ( packageName == null ) { int index = line . indexOf ( "package" ) ; if ( index >= 0 ) { index += 7 ; int end = line . indexOf ( ';' , index ) ; if ( end >= index ) { packageName = line . substring ( index , end ) ; packageName = packageName . trim ( ) ; } } } if ( className == null ) { int index = line . indexOf ( "%class" ) ; if ( index >= 0 ) { index += 6 ; className = line . substring ( index ) ; className = className . trim ( ) ; } } } if ( className == null ) className = "Yylex" ; }
target:  Peek into .flex file to get package and class name