file getting corrupted after transfering using apa

问题:

i have done file uploading partially successful .the file with extension-.html,.jpeg,.pdf etc works fine.when it comes to .zip,.rpm,.tar.gz it doesn't works.the file is getting transferred to the desired path but the file is corrupted.

<tr>  
 <td>FileName</td>  
 <td><input type="text" name="filename" size="30"/></td>  
</tr> 
<tr>  
 <td>Select main category</td>  
 <td>  
  <select name="main">  
   <option >--Select--</option>  
   <option>aerospace</option>  
   <option>automotive</option>  
   <option>energy</option>  
   <option>icengines</option>  
   <option>wind</option>  
   <option>turbo</option>  
   <option>it</option>
   <option>training</option>  
  </select>  
 </td>  
</tr>  
<tr>  
    <td>Select sub category</td>
 <td>  
  <select name="sub">  
   <option >--Select--</option>  
   <option>internal</option>  
   <option>demo</option>  
   <option>best practice</option>  
   <option>marketing</option>  
   <option>papers & public</option>  
   <option>validation</option>  
   <option>training</option>  
  </select>  
 </td>  
</tr>  


<tr>  
 <td>Upload File</td>  
 <td><input type="file" name="file1"/></td>  
</tr> 

it will get the filename along with the dropdown values and type="file",the file is transferred to the desired path but the file is corrupted for above mentioned formats(i have checked with those formats alone).i need all the file to be stored without getting corrupted.

my servlet:

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
private String filename="";     
private String main1="";  
private String location;  
private String sub;
private File uploadFile;  
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {  
try {  
PrintWriter out = response.getWriter();  

DiskFileItemFactory factory = new DiskFileItemFactory();  
ServletFileUpload fileUpload = new ServletFileUpload(factory);         
List items = fileUpload.parseRequest(request);  
Iterator ir = items.iterator();  
while(ir.hasNext()){  
FileItem item = (FileItem)ir.next();  


if(item.isFormField())
{ 

 String name = item.getFieldName();  

 if(name != null)  
 {  
 if(name.equals("userName"))
 {  
  filename = item.getString();  
 }

 else if(name.equals("main"))
 {  
  main1 = item.getString();  
 }
 else if(name.equals("sub"))
 {
     sub=item.getString();
 }
 }  
}else{  

 location = File.separator+"home"+File.separator+"adapco"+File.separator+"Desktop"+ File.separator +"output"+ File.separator +main1+File.separator+sub+File.separator+filename;
 uploadFile = new File(location);        
 long size = item.getSize();  
 if(size <= 1024*1024*1024)
 {  
  item.write(uploadFile);  
  out.println("Your File is uploaded successfully ");  
 }else{  
  out.println("Your File is not uploaded.File size should be less than 1gb");  
 }  
}  
}  
} catch (Exception e) {  
}  
}   

}