I took the following code from a tutorial:
import javax.swing.*;
import java.util.Date;
public class SwingGUI {
public static void main( String[] args
I get this problem too. unfortunately to resolve it I was needed to install my eclipse. but I think that the problem was incompatibility between JRE and JAVA version in Eclipse.
I used JRE supported JAVA8 when my project (and my eclipse indigo) can't upgrade to JAVA8. Updating to another eclipse that can support java 8 solve the problem.