question: public static String mergePath ( String current , String realPath ) throws MalformedURLException { String currDir ; if ( current == null || current . indexOf ( '/' ) == - 1 ) currDir = "/" ; else if ( current . endsWith ( "/" ) ) currDir = current ; else currDir = current . substring ( 0 , current . lastIndexOf ( '/' ) + 1 ) ; String path ; if ( realPath . startsWith ( "./" ) ) path = currDir + realPath . substring ( 2 ) ; else if ( realPath . startsWith ( "/" ) ) path = realPath ; else if ( ! realPath . startsWith ( "../" ) ) path = currDir + realPath ; else { while ( realPath . startsWith ( "../" ) || currDir . length ( ) == 0 ) { realPath = realPath . substring ( 3 ) ; currDir = currDir . substring ( 0 , currDir . length ( ) - 1 ) ; int index = currDir . lastIndexOf ( '/' ) ; if ( index == - 1 ) throw new MalformedURLException ( "invalid realpath definition for URL" ) ; currDir = currDir . substring ( 0 , index + 1 ) ; } path = currDir + realPath ; } return path ; }
target:  merge to pathes to one