Why does Java automatically decode %2F in URI encoded filenames?
- by Lucas
I have a java servlet that needs to write out files that have a user-configurable name. I am trying to use URI encoding to properly escape special characters, but the JRE appears to automatically convert encoded forward slashes (%2F) into path separators.
Example:
File dir = new File("C:\Documents and Setting\username\temp");
String fn = "Top 1/2.pdf";
URI uri = new URI( dir.toURI().toASCIIString() + URLEncoder.encoder( fn, "UTF-8" ).toString() );
File out = new File( uri );
System.out.println( dir.toURI().toASCIIString() );
System.out.println( URLEncoder.encoder( fn, "UTF-8" ).toString() );
System.out.println( uri.toASCIIString() );
System.out.println( output.toURI().toASCIIString() );
The output is:
file:/C:/Documents%20and%20Settings/username/temp/
Top+1%2F2.pdf
file:/C:/Documents%20and%20Settings/username/temp/Top+1%2F2.pdf
file:/C:/Documents%20and%20Settings/username/temp/Top+1/2.pdf
After the new File object is instantiated, the %2F sequence is automatically converted to a forward slash and I end up with an incorrect path. Does anybody know the proper way to approach this issue?
The core of the problem seems to be that
uri.equals( new File(uri).toURI() ) == FALSE
when there is a '%2F' in the URI.
I'm planning to just use the URLEncoded string verbatim rather than trying to use the File(uri) constructor.
