How to encode xml to Base64 and send back as servlet response? - servlets

Question

I wrote a servlet (with .groovy extension) which should return xml in Base64 encoding
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
String fileName=(String) request.getParameter("fileName")
if (fileName == null || fileName.equals(""))throw new ServletException("Invalid or non-existent file parameter in SendXml servlet.")
if (fileName.indexOf(".xml") == -1)fileName = fileName + ".xml"
System.out.println(fileName)
try {
String relativeWebPath = "/WEB-INF/classes/com/abc/csm/xml/"+fileName
String absoluteDiskPath = getServletContext().getRealPath(relativeWebPath)
String fileContents=new File(absoluteDiskPath).text
response.setContentType("text/xml")
response.addHeader("Content-Disposition", "attachment filename="+ fileName)
XmlHandler xm=new XmlHandler()
PrintWriter out = response.getWriter()
String enxml=xm.encodeBase64(fileContents)
response.setContentLength((int) enxml.length)
out.println(enxml)
out.close()
out.flush()
} catch (Exception e) { println e }
}
XmlHandler encodeBase64 method
def encodeBase64(String text) {
return new String(Base64.encodeBase64(text.getBytes()))
}
But I guess something is missing. Please help
Update
Also please comment is it proper way to access files from package?

Answer 1

You can replace:
String enxml=xm.encodeBase64(fileContents)
with
String enxml = fileContents.bytes.encodeBase64()
Or, better to pass an encoding to the call to getBytes:
String enxml = fileContents.getBytes( 'UTF-8' ).encodeBase64()
Also, I believe you're missing a semicolon after attachment in your header... The line should read:
response.addHeader( "Content-Disposition", "attachment; filename=$fileName" )
Edit, and encoding and decoding example:
Encode:
String encoded = "tim_yates".getBytes( 'UTF-8' ).encodeBase64()
Decode:
String original = new String( encoded.decodeBase64(), 'UTF-8' )
assert original == 'tim_yates'