title: Java can't find symbol
body: <p>This is my error message</p>
  
  <pre><code>test.java:17: cannot find symbol
  symbol  : class MouseAdapter
  location: class test
          private class click extends MouseAdapter
                                      ^
  test.java:19: cannot find symbol
  symbol  : class MouseEvent
  location: class test.click
                  public void mouseEntered(MouseEvent e)
                                           ^
  test.java:14: cannot find symbol
  symbol  : variable trayicon
  location: class test
          trayicon.addMouseListener(new click());
          ^
  3 errors
  </code></pre>
  
  <hr>
  
  <pre><code>import javax.swing.*;
  import javax.swing.event.*;
  import java.awt.*;
  
  public class test extends JFrame
  {
  
      private JFrame frame;
  
      public void init()
      {
          trayicon.addMouseListener(new click());
      }
  
          private class click extends MouseAdapter
          {
              public void mouseEntered(MouseEvent e)
              {
                  {
                  frame.setVisible(true);
              }
          }
      }
  }
  </code></pre>