编译时出现Java Applet错误

Question

我正在编写一个程序，该程序应该创建3张图像，并使用Applet通过Java为它们着色。编译后，Eclipse会抛出大量错误，我不知道如何解决该问题。

我已经研究了这个问题，并且发现有人指出我需要作为配置运行，并将JRE环境更改为较新的版本，但是我已经使用了最新的环境。

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Polygon;
import javax.swing.JApplet;

public class GraphicalImages extends JApplet {

  private String shapeType;

  public void init() {

        // Get width

        int width = Integer.parseInt(getParameter("width"));

        // Get height

        int height = Integer.parseInt(getParameter("height"));

        // Set dimension

        setSize(width, height);

        // Get shape

        shapeType = getParameter("shapeType");

  }

  public void paint(Graphics g) {

        // Check shape type

        if (shapeType.equalsIgnoreCase("bus")) {

              // Draw chassis

              g.setColor(Color.YELLOW);

              g.fillRect(100, 100, 350, 150);

              g.fillRect(450, 150, 80, 100);

              // Draw windows

              g.setColor(Color.LIGHT_GRAY);

              g.fillRect(120, 130, 40, 40);

              g.fillRect(190, 130, 40, 40);

              g.fillRect(260, 130, 40, 40);

              g.fillRect(330, 130, 40, 40);

              g.fillRect(400, 130, 40, 40);

              // Draw door

              g.fillRect(460, 170, 30, 60);

              // Draw wheels

              g.setColor(Color.BLACK);

              g.fillOval(140, 230, 50, 50);

              g.fillOval(425, 230, 50, 50);

        } else if (shapeType.equalsIgnoreCase("flower")) {

              // Draw petals

              g.setColor(Color.CYAN);

              g.fillOval(250, 100, 99, 99);

              g.fillOval(184, 156, 99, 99);

              g.fillOval(316, 156, 99, 99);

              g.fillOval(217, 232, 99, 99);

              g.fillOval(283, 232, 99, 99);

              // Draw center

              g.setColor(Color.YELLOW);

              g.fillOval(250, 170, 99, 99);

        } else if (shapeType.equalsIgnoreCase("tree")) {

              // Set color

              g.setColor(Color.GREEN);

              // Draw top

              Polygon polygon = new Polygon();

              polygon.addPoint(300, 50);

              polygon.addPoint(243, 125);

              polygon.addPoint(357, 125);

              g.fillPolygon(polygon);

              // Draw middle

              polygon.reset();

              polygon.addPoint(300, 75);

              polygon.addPoint(218, 200);

              polygon.addPoint(382, 200);

              g.fillPolygon(polygon);

              // Draw bottom

              polygon.reset();

              polygon.addPoint(300, 125);

              polygon.addPoint(193, 275);

              polygon.addPoint(407, 275);

              g.fillPolygon(polygon);



              // Draw truck

              g.setColor(Color.BLACK);

              g.fillRect(270, 275, 60, 250);

        }

  }}

错误提示：

Warning: Can't read AppletViewer properties file: 
C:\Users\Khaos\.hotjava\properties Using defaults.
Exception in thread "AWT-EventQueue-1" java.lang.NullPointerException
at GraphicalImages.paint(GraphicalImages.java:40)
at javax.swing.RepaintManager$4.run(Unknown Source)
at javax.swing.RepaintManager$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
at javax.swing.RepaintManager.prePaintDirtyRegions(Unknown Source)
at javax.swing.RepaintManager.access$1200(Unknown Source)
at javax.swing.RepaintManager$ProcessingRunnable.run(Unknown Source)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$500(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
Exception in thread "AWT-EventQueue-1" java.lang.NullPointerException
at GraphicalImages.paint(GraphicalImages.java:40)
at javax.swing.RepaintManager$4.run(Unknown Source)
at javax.swing.RepaintManager$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
at javax.swing.RepaintManager.prePaintDirtyRegions(Unknown Source)
at javax.swing.RepaintManager.access$1200(Unknown Source)
at javax.swing.RepaintManager$ProcessingRunnable.run(Unknown Source)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$500(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)