cannot find symbol error while using jframe

Question

I already have a class called validation that looks like this:

package Information;

public class Validation {

    public static boolean emptyString(String s) {
        if (s == null || s.isEmpty()) {
            return true;
        } else {
            return false;
        }
    }
}

This is my Jframe class:

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {

    if (Validation.emptyString(jTextField1.getText()) || Validation.emptyString(jTextField2.getText()))

    {
        JOptionPane.showMessageDialog(null, "Don't leave fields empty");
    } else {
        if (testaAdmin(jTextField1.getText(), jTextField2.getText())) {
            Basen basenFrame = new Basen();
            basenFrame.setVisible(true);
            this.dispose();
        } else {
            JOptionPane.showMessageDialog(null, "Wrong username or password");
        }

    }

}

The problem is that Validation in the Jframe class doesn't seem to get that it is supposed to communicate with the Validation class.

It just gives me this error message:

error: cannot find symbol Validation.emptyString(jTextField2.getText()))

Why is this?

Have you imported the (unconventionally-named) `Information` package in your source file for the JFrame? — Jon Skeet, May 15 '15 at 10:12
pls refactor your emptyString functionto : `return s == null || s.isEmpty()` — Dude, May 15 '15 at 10:14

score 0 · Answer 1 · edited May 23 '17 at 12:14

The problem is probably due to a missing import. If the Validation class is in a different package from the JFrame, it will need to be explicitly imported as per MrWiggles answer:

import Information.Validation;

I'd strongly suggest you download an an IDE, e.g. Eclipse or IntelliJ, as it will give you much more informative messages than the compiler and automated assistance to fix them.

Also, when you get a compiler error, you might use Google to find an explanation and save having to post a question on StackOverflow. You just need to omit your application-specific terms. Searching for: "error: cannot find symbol" finds a long StackOverflow post on the subject.

score -1 · Answer 2 · answered May 15 '15 at 10:13

-1

You need to ensure you've imported your validation class. In the class you've got your JFrame, make sure you've got this line at the top:

import Information.Validation;

answered May 15 '15 at 10:13

tddmonkey

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This should've been (and is, by someone else) a comment. – wonderb0lt May 15 '15 at 10:14
3

Which was written while I was typing the answer - the fact its a comment doesn't make this any less of an answer to the problem – tddmonkey May 15 '15 at 10:15
Thanks but now I get this error message instead: error: expected import Information.Validation.; – thunderboard May 15 '15 at 10:19
What error are you getting? – tddmonkey May 15 '15 at 10:20
@MrWiggles: Fair enough. Sorry for being so aggressive. – wonderb0lt May 15 '15 at 10:21
2

If it's exactly as you've typed it, you have an extra `.` at the end, before the semicolon - enter the code exactly as I put it in the answer. – tddmonkey May 15 '15 at 10:23

cannot find symbol error while using jframe

2 Answers2