对于GUI设计来说，如果你用AWT，paint()是你要用的东西；如果你用Swing，paintComponent()是你要用的东西。 Painting is much different in Swing than it is in AWT. In AWT we typically override Component’s paint() method to do rendering and the update() method for things like implementing our own double-buffering or filling the background before paint() is called.With Swing, component rendering is much more complex. Though JComponent is a subclass of Component, it uses the update() and paint() methods for different reasons. In fact, the update() method is never invoked at all. There are also five additional stages of painting that normally occur from within the paint() method. ... but it suffices to say here that any JComponent subclass that wants to take control of its own rendering should override the paintComponent() method and not the paint() method. Additionally, it should always begin its paintComponent() method with a call to super.paintComponent().
关于这两个类的区别，看它们的api文档描述
paintComponent只是重画上面的容器
所以很明显的
后者速度比前者要快
一般情况下都是用后者的
除非对于JFrame，才会用到前者
LZ可以体会一下哈~
Painting is much different in Swing than it is in AWT. In AWT we typically override Component’s paint() method to do rendering and the update() method for things like implementing our own double-buffering or filling the background before paint() is called.With Swing, component rendering is much more complex. Though JComponent is a subclass of Component, it uses the update() and paint() methods for different reasons. In fact, the update() method is never invoked at all. There are also five additional stages of painting that normally occur from within the paint() method. ... but it suffices to say here that any JComponent subclass that wants to take control of its own rendering should override the paintComponent() method and not the paint() method. Additionally, it should always begin its paintComponent() method with a call to super.paintComponent().