Struts File Upload identify correct extension instead of .tmp - struts2

Question

I am new to Struts and working on File Upload using Struts.
Client:
It is Java Program which hits my Strut app by using apache HttpClient API and provides me
File.
Client as per need sometime gives me .wav file and sometime .zip file and sometime both.
Server:
Struts app which got the request from client app and upload the file.
Here, problem comes as I upload the file, it get uploaded using ".tmp" extension, which I want to get uploaded with the same extension what client has passed.
Or there is any other way by which we can check what is the extension of the file client has sent....?
I am stuck in this problem and not able to go ahead.
Please Find the code attached and tell me what modification I have to do:
Server Code:
MultiPartRequestWrapper multiWrapper=null;
File baseFile=null;
System.out.println("inside do post");
multiWrapper = ((MultiPartRequestWrapper)request);
Enumeration e = multiWrapper.getFileParameterNames();
while (e.hasMoreElements()) {
// get the value of this input tag
String inputValue = (String) e.nextElement();
// Get a File object for the uploaded File
File[] file = multiWrapper.getFiles(inputValue);
// If it's null the upload failed
if (file != null) {
FileInputStream fis=new FileInputStream(file[0]);
System.out.println(file[0].getAbsolutePath());
System.out.println(fis);
int ch;
while((ch=fis.read())!=-1){
System.out.print((char)ch);
}
}
}
System.out.println("III :"+multiWrapper.getParameter("method"));
Client code:
HttpClient client = new HttpClient();
MultipartPostMethod mPost = new MultipartPostMethod(url);
File zipFile = new File("D:\\a.zip");
File wavFile = new File("D:\\b.wav");
mPost.addParameter("recipientFile", zipFile);
mPost.addParameter("promptFile", wavFile);
mPost.addParameter("method", "addCampaign");
statusCode1 = client.executeMethod(mPost);
actually Client is written long back and cant be modified and I want to identify something at server side only to find the extension.
Please help, Thanks.

Answer 1

Struts2 File Uploader interceptor when uploading file pass the content type information to the Action class and one can easily find the file type by comparing contentType with MIME type.
If you want to can create a map with key as content type and file type as its value like
map.Add("image/bmp",".bmp", )
map.Add("image/gif",".gif", )
map.Add("image/jpeg",".jpeg", )
and can easily fetch the type based on the extension provides.Hope this will help you.