JBuilderの利用法
Exception occurred during event dispatching: java.lang.NullPointerException at jdraw.Applet1.paint(Applet1.java:121) at java.awt.Container.update(Container.java:981) at sun.awt.RepaintArea.update(RepaintArea.java:337) at sun.awt.windows.WComponentPeer.handleEvent(WComponentPeer.java:200) at java.awt.Component.dispatchEventImpl(Component.java:2663) at java.awt.Container.dispatchEventImpl(Container.java:1213) at java.awt.Component.dispatchEvent(Component.java:2497)