Check file extension in Java

Question

I have to import data from an Excel file to database and to do this, I would like to check the extension of the chosen file.

This is my code:

String          


        

Answer 1

You can use Apache Commons Api to check the file extension

String filename = file.getName();
if(!FilenameUtils.isExtension(filename,"xls")){
  JOptionPane.showMessageDialog(null, "Choose an excel file!");
}

http://commons.apache.org/io/api-release/index.html?org/apache/commons/io/package-summary.html

Answer 2

use equals() method instead of != symbols in your case. I mean write

if (!(extension.equals(excel))){..........}

Answer 3

How about

if (filename.endsWith("xls"){
    <blah blah blah>
}

?

Answer 4

== tests referentially equality. For value equality test, use .equals. Use String#equalsIgnoreCase if you want the case to be disregarded during the equality test.

Another thing: Don't reinvent the wheel, unless it's badly broken. In your case, you should be using Apache Commons' FilenameUtils#isExtension to check the extension.

Answer 5

use

excel.equals(extension)

or

excel.equalsIgnoreCase(extension)

Answer 6

if (extension != excel){
   JOptionPane.showMessageDialog(null, "Choose an excel file!");

}

should be used as

if (!extension.equals(excel)){
   JOptionPane.showMessageDialog(null, "Choose an excel file!");

}

And

 if (upload == "OK") {
 JOptionPane.showMessageDialog(null,"Upload Successful!");
}

as

 if ("OK".equals(upload)) {
 JOptionPane.showMessageDialog(null,"Upload Successful!");
}