jsp画图

<%@ page language="java" contentType="text/html; charset=gbk"
    pageEncoding="gbk" import="javax.imageio.*,java.awt.*,java.awt.image.*"%>
<%
    int width=400;
    int height=400;
    BufferedImage image=new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
    
    Graphics g=image.getGraphics();
    g.setColor(Color.red);
    g.drawLine(20,20,220,20);
    g.setColor(Color.white);
    g.dispose();
    ImageIO.write(image,"jpg",response.getOutputStream());
    out.clear();
    out = pageContext.pushBody();     
%>

背景色是漆黑的,怎么设置背景色
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解决了

g.setColor(Color.white);
g.fillRect(0,0,width,height);
----------------解决方案--------------------------------------------------------