问答题

本题是设计一个窗体，窗口的背景色为系统桌面的颜色，在窗口中分别画了空心和实心的黑色矩形、深灰色圆角矩形和浅灰色椭圆形，并且画了白色粗体的"Java二级考试!"字符串。 Import java.awt.*; Import javax.swing.*; Public class java2 { Public static void main(string[] args) { Fillframe frame=new fillframe(); Frame.setdefaultcloseoperation(jframe.exit_on_close); Frame.show(); } } Class fillframe extends jframe { Public fillframe() { Settitle("simple"); Setsize(width,height); Fillpanel panel=new fillpanel(); Panel.setbackground(systemcolor.desktop); Container contentpane=getcontentpane(); Contentpane.add(panel); } Public static final int width=400; Public static final int width=250; } Class fillpanel extends jpanel { Public void paintcomponent(graphics g) { ______; g.setcolor(new color(10,10,10)); g.drawrect(10,10,100,30); g.setcolor(new color(100,100,100)); g.drawroundrect(150,10,100,30,15,15); g.setcolor(new color(150,150,150)); g.drawoval(280,10,80,30); g.setcolor(new color(10,10,10)); g.fillrect(10,110,100,30); g.setcolor(new color(100,100,100)); g.drawroundrect(150,110,100,30,15,15); g.setcolor(new color(150,150,150)); g.filloval(280,110,80,30); g.setcolor(color.white); font f=new font("宋体",______,20); g.setfont(f); g.drawstring("java二级考试!",150,200); } }