为什么java绘图显示不了图形
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class text01 extends JFrame{
text01(){
this.setTitle("hii");
this.setVisible(true);
this.setSize(500,300);
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
this.getContentPane().add(new Apanel());

}
public static void main(String args[]){
new text01();
}
}
class Apanel extends JPanel{
public void painComponent(Graphics g){
super.paintComponent(g);
g.setColor(Color.blue);
g.drawRect(30, 30, 100, 100);
g.drawRoundRect(140, 30, 100, 100, 60, 30);
}
}
图形 Java
[解决办法]

public void painComponent(Graphics g){
super.paintComponent(g);
g.setColor(Color.blue);
g.drawRect(30, 30, 100, 100);
g.drawRoundRect(140, 30, 100, 100, 60, 30);
}

方法名写错了
paintComponent
[解决办法]
为了防止继承的方法写错，最好在方法的前面加上一个@Override，这样当写错的时候Java会提示错了，解决输入错误很好用。
例如

@Override
public void paintComponent(Graphics g) {


}