Problemas com execução da classe

java.lang.UnsupportedClassVersionError: Bad version number in .class file
	at java.lang.ClassLoader.defineClass1(Native Method)
	at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:124)
	at java.net.URLClassLoader.defineClass(URLClassLoader.java:260)
	at java.net.URLClassLoader.access$100(URLClassLoader.java:56)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:195)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:268)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
	at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
Exception in thread "main"

package main;

import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartUtilities;
import org.jfree.chart.JFreeChart;
import org.jfree.data.general.DefaultPieDataset;
import java.io.File;

public class PieChartExample {
	public static void main (String []args){
		//create a simple pie chart
		DefaultPieDataset pieDataset = new DefaultPieDataset();
		pieDataset.setValue("A", new Integer(75));
		pieDataset.setValue("B", new Integer(10));
		pieDataset.setValue("C", new Integer(10));
		pieDataset.setValue("D", new Integer(5));
		JFreeChart chart = ChartFactory.createPieChart(
				"CSC408 Mark Distribution",
                pieDataset, 
                true, 
                true, 
                false);
        try {
            ChartUtilities.saveChartAsJPEG(new File("C:chart.jpg"), chart, 500,
                300);
        } catch (Exception e) {
            System.out.println("Problem occurred creating chart.");
        }
    }
}