java. lang.ClassLoader. Error in loadclass (unknown source)

For my paper, I try to deal with some things with pictures. One step to complete it is to find the corners in the pictures After some surfing, I found that it can be implemented with Moravec's corner detection algorithm Fortunately, I found that Moravec's algorithm has been implemented by jfeaturelib on this link: https://code.google.com/p/jfeaturelib/source/browse/src/main/java/de/lmu/ifi/dbs/jfeaturelib/pointDetector/Moravec.java?r=8d96a8fa9a43a0ec7e7084b40169be56bddd6f36

(of course, I imported the jar file provided by jfeaturelib in the eclipse build path) so I used the code in the project link and wrote some code to call it This is the code for me to create a frame, open the picture and call the Moravec algorithm on the link:

import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;




public class Compare{
    public Compare(){
        JFrame frame = new JFrame("Find corners in picture");
        frame.setDefaultCloSEOperation(JFrame.EXIT_ON_CLOSE);
        JPanel panel = (JPanel)frame.getContentPane();
        JLabel label = new JLabel();
        label.setIcon(new ImageIcon("house.jpg"));
        panel.add(label);
        frame.setLocationRelativeTo(null);
        frame.pack();
        frame.setVisible(true);
    }
    public static void main (String[] args){
        SwingUtilities.invokelater(new Runnable(){
            public void run(){
                new Compare();
            }
        });
        Moravec picture = new Moravec();
    }
}

The key is that it returns an error on the line

Moravec picture = new Moravec();

The error is as follows:

Exception in thread "main" java.lang.UnsupportedClassVersionError: de/lmu/ifi/dbs/jfeaturelib/pointDetector/PointDetector : Unsupported major.minor version 51.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(UnkNown Source)
at java.lang.ClassLoader.defineClass(UnkNown Source)
at java.security.SecureClassLoader.defineClass(UnkNown Source)
at java.net.urlclassloader.defineClass(UnkNown Source)
at java.net.urlclassloader.access$000(UnkNown Source)
at java.net.urlclassloader$1.run(UnkNown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.urlclassloader.findClass(UnkNown Source)
at java.lang.ClassLoader.loadClass(UnkNown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(UnkNown Source)
at java.lang.ClassLoader.loadClass(UnkNown Source)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(UnkNown Source)
at java.lang.ClassLoader.defineClass(UnkNown Source)
at java.security.SecureClassLoader.defineClass(UnkNown Source)
at java.net.urlclassloader.defineClass(UnkNown Source)
at java.net.urlclassloader.access$000(UnkNown Source)
at java.net.urlclassloader$1.run(UnkNown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.urlclassloader.findClass(UnkNown Source)
at java.lang.ClassLoader.loadClass(UnkNown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(UnkNown Source)
at java.lang.ClassLoader.loadClass(UnkNown Source)
at Compare.main(Compare.java:32)

Can you give me some advice? Thank you.

Solution

Unsupported major Minor version 51.0

Execute Java - version and see if this is the case If so, find JDK 7 on your system and use it to run your program