Konloch/bytecode-viewer · info · InputMismatchException

Empty value not valid

Error message

Empty value not valid

What it means

The character field handler throws InputMismatchException("Empty value not valid") when the text field is empty at key release, because there is no character to encode into the values cache. It is an immediate-validation guard, not a runtime failure.

Source

Thrown at src/main/java/the/bytecode/club/bytecodeviewer/gui/hexviewer/ValuesPanel.java:603

                updateValues();
            }
            catch (NumberFormatException ex)
            {
                showException(ex);
            }
        }
    }//GEN-LAST:event_doubleTextFieldKeyReleased

    private void characterTextFieldKeyReleased(java.awt.event.KeyEvent evt)
    {//GEN-FIRST:event_characterTextFieldKeyReleased
        if (evt.getKeyCode() == KeyEvent.VK_ENTER && isEditable())
        {
            try
            {
                String characterText = characterTextField.getText();

                if (characterText.length() == 0)
                    throw new InputMismatchException("Empty value not valid");

                if (characterText.length() > 1)
                    throw new InputMismatchException("Only single character allowed");

                byte[] bytes = characterText.getBytes(codeArea.getCharset());
                System.arraycopy(bytes, 0, valuesCache, 0, bytes.length);

                modifyValues(bytes.length);
                updateValues();
            }
            catch (InputMismatchException ex)
            {
                showException(ex);
            }
        }
    }//GEN-LAST:event_characterTextFieldKeyReleased

    private void stringTextFieldKeyReleased(java.awt.event.KeyEvent evt)

View on GitHub (pinned to 31430e0033)

Solutions

1. Type exactly one character into the field.
2. If you want to clear the bytes, use the hex editor's clear/undo functions instead of emptying the field.
3. Ignore the message until a character is present; it is non-destructive validation feedback.

Example fix

// before
characterTextField.setText(""); // throws on next keyReleased
// after
characterTextField.setText("A"); // exactly one character

try {
    applyCharacterValue(characterTextField.getText());
} catch (InputMismatchException e) {
    // field empty or multi-char; wait for valid input
    setStatus(e.getMessage());
}

When it happens

Trigger: characterTextFieldKeyReleased with characterText.length() == 0 — e.g. clearing the character field completely.

Common situations: Deleting the character with backspace and continuing to type/press keys; clearing the field expecting the hex view to reset; focus/key events firing after the text was emptied.

Related errors

• Only single character allowed
• Value out of range
• String is too long
• Invalid Java .class file

AI-assisted analysis of Konloch/bytecode-viewer@31430e0033 (2026-09-05). Data as JSON: /api/errors/37c6547d976e6465. Report an issue: GitHub.