Question

The following code gives me compile-time errors: missing return value and missing return statement, what value would I return for this Void Type?

final SwingWorker<Void, Void> worker = new SwingWorker<Void, Void>() {
    @Override
    protected Void doInBackground() throws Exception {
        // some code
        if (something) {
            return;
        }
    }
}

Answer 1

Void is not void, change it to void type if you don’t want to return anything.

Void is a class, void is type.

/**
 * The {@code Void} class is an uninstantiable placeholder class to hold a
 * reference to the {@code Class} object representing the Java keyword
 * void.
 *
 * @author  unascribed
 * @since   JDK1.1
 */

If you want Void, then you need to add return statement at end.

Example:

protected Void doInBackground() throws Exception {
    // some code
    if (something) {
       return null;
    }
    return null;
}