How to find the extension of uploaded file in java?

Question

I have the following code to upload the files, when I use the file.getNeme it shows the temporary file name that has the tmp extension, how can I find the extension of the actual upload file? the file that I am uploading is called test.jpg

import java.io.File;
import org.apache.commons.io.FileUtils;

public class FileUploder {

  private File file;

  public File getFile() {
        return file;
  }

  public void setFile(File file) {
        this.file = file;
  }
   ......

  System.out.println("file:" +file.getName());  
  try {
        File fileToCreate = new File(filePath,name);
        FileUtils.copyFile(file, fileToCreate);
  } catch (IOException ex) {
        ex.printStackTrace();
  }

  ......

the current output is similar to >>> file:upload__1a6d32_13d0eda6d49__7fdf_00000012.tmp

Answer 1

   private String getImageFileExtendtion (FileItem item) {
        String formatName = "png";
        String fileName = item.getName();
        if (fileName != null && fileName.length() >0) {
            int index = -1;
             for (int i = fileName.length()-1 ; i >=0; i --) {
                 if (fileName.charAt(i)=='.') {
                     index = i;
                     break;
                 }
             }
            if (index >=0 && index < fileName.length() -1) {
                 formatName = fileName.substring(index+1);
            }
        }
        return formatName ;
    }

Answer 2

Just add another getter/setter as below and also remove the getFile() method and it will work

private String fileFileName;

public String getFileFileName() {
    return fileFileName;
}

public void setFileFileName(String fileFileName) {
    this.fileFileName = fileFileName;
}

Answer 3

You should not use file.getName()

http://struts.apache.org/release/2.0.x/docs/file-upload.html#FileUpload-BasicUsage

setX(File file)  
    The file that contains the content of the uploaded file. This is a temporary file and file.getName() will not return the original name of the file

Instead, create another setter setFileName(String fileName) should do.