question: private static String replaceChars ( String str ) { StringBuffer buf = new StringBuffer ( str ) ; int length = buf . length ( ) ; for ( int i = 0 ; i < length ; i ++ ) { char currentChar = buf . charAt ( i ) ; if ( currentChar == ' ' ) { buf . setCharAt ( i , '%' ) ; buf . insert ( i + 1 , "20" ) ; length = length + 2 ; i = i + 2 ; } else if ( currentChar == '\\' ) { buf . setCharAt ( i , '/' ) ; } } return buf . toString ( ) ; }
target:  Replace spaces with "%20" and backslashes with forward slashes in  the input string to generate a well-formed URI string.