The problem of FormDataContentDisposition in Jersey File Upload - upload

Question

import org.glassfish.jersey.media.multipart.FormDataContentDisposition;
import org.glassfish.jersey.media.multipart.FormDataParam;
#Path("/files")
public class FileUploadService {
#POST
#Path("/upload")
#Consumes(MediaType.MULTIPART_FORM_DATA)
#Produces({"text/plain","application/xml","application/json"})
public Response uploadPdfFile( #FormDataParam("file") InputStream fileInputStream,
#FormDataParam("file") FormDataContentDisposition fileMetaData) throws Exception
{
//String UPLOAD_PATH = "f://";
String UPLOAD_PATH = "c://temp//";
try
{
int read = 0;
byte[] bytes = new byte[102400];
OutputStream out = new FileOutputStream(new File(UPLOAD_PATH +
fileMetaData.getFileName()));
//OutputStream out = new FileOutputStream(new File(UPLOAD_PATH + "xx.txt"));
while ((read = fileInputStream.read(bytes)) != -1)
{
out.write(bytes, 0, read);
}
out.flush();
out.close();
} catch (IOException e)
{
throw new WebApplicationException("Error while uploading file. Please try again !!");
}
return Response.ok("Data uploaded successfully !!").build();
}
}
A code of Jersey upload was running. If I use OutputStream out = new FileOutputStream(new File(UPLOAD_PATH + "xx.txt")), it is good and I can see the xx.txt file in c:\temp folder.
However, if I use OutputStream out = new FileOutputStream(new File(UPLOAD_PATH + fileMetaData.getFileName())), it said Data uploaded successfuly!!, but I cannot see anything in c:\temp folder.
Did this FormDataContentDisposition have any bug? Or I use it in wrong way?
The line "return Response.ok("Data uploaded successfully !!").build();" will return "Data uploaded successfully !!".
However, if I change the line "return Response.ok("Data uploaded successfully !!").build(); to return Response.ok("Data uploaded successfully !!"+fileMetaData.getFileName()).build();
I got the results of "Data uploaded successfully !!C:CodingWeb services16.JAX-RS File Upload Exampletest.txt".
Why did fileMetaData.getFileName() return "C:CodingWeb services16.JAX-RS File Upload Exampletest.txt"?