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 filename = file.getName();
String extension = filename.substring(filename.lastIndexOf(".") + 1, filename.length());

String excel = "xls";
if (extension != excel) {
    JOptionPane.showMessageDialog(null, "Choose an excel file!");
}
else {
    String filepath = file.getAbsolutePath();
    JOptionPane.showMessageDialog(null, filepath);
    String upload = UploadPoData.initialize(null, filepath);

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

But I always get:

Choose an excel file!

I can’t find what is wrong with my code, could someone please help.

Answer 1

following

extension != excel

should be

!excel.equals(extension)

or

!excel.equalsIgnoreCase(extension)

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See also

• String equals() versus ==