rectangle2dtest.jsp

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<!--
	Fig. 7.5_04_01: rectangle2DTest.jsp
	功能: Rectangle2D的使用方法
-->
<%@ page language="java" contentType="image/png;charset=GB2312"
	import="java.awt.*"
	import="javax.imageio.*"
	import="java.awt.geom.*"
	import="java.awt.image.*"
%>

<%
// 清空缓冲区
response.reset();

// 注意这里的MIME类型
response.setContentType("image/png");

// 创建一个 400X400 的图像
int width = 400, height = 400;

BufferedImage image = new BufferedImage(width, height,
  BufferedImage.TYPE_INT_RGB);

// 创建Java2D对象
Graphics2D g2d = image.createGraphics();

// 填充背景
g2d.setColor(Color.WHITE);
g2d.fillRect(0, 0, width, height);

g2d.setPaint(Color.YELLOW);

// 创建Rectangle2D对象
Rectangle2D.Float r1 = new Rectangle2D.Float(10.0f, 10.0f, 100.0f, 70.0f);
Rectangle2D.Float r2 = new Rectangle2D.Float(60.0f, 50.0f, 100.0f, 70.0f);

Rectangle2D.Double r3 = new Rectangle2D.Double(180.0, 10.0, 100.0, 70.0);
Rectangle2D.Double r4 = new Rectangle2D.Double(230.0, 50.0, 100.0, 70.0);

// 填充用createIntersection以及createUnion得到的新的矩形
g2d.fill(r1.createIntersection(r2));
g2d.fill(r3.createUnion(r4));

// 创建虚线笔划
float[] dashes = { 3.f };
BasicStroke bs = new BasicStroke(1.0f, BasicStroke.CAP_ROUND, 
	BasicStroke.JOIN_ROUND, 10, dashes, 0);
g2d.setStroke(bs);

// 绘制矩形
g2d.setPaint(Color.BLACK);
g2d.draw(r1);
g2d.draw(r2);
g2d.draw(r3);
g2d.draw(r4);

// 部署图形
g2d.dispose();

// 利用ImageIO类的write方法对图像进行编码
ServletOutputStream sos = response.getOutputStream();
ImageIO.write(image, "PNG", sos);
sos.close();
%>

<%
/**************************************************************************
 * (C) Copyright 2004-2005 by Jingkui Zhong(钟京馗) and Huan Tang(唐桓).  *
 * All Rights Reserved.                                                   *
 *                                                                        *
 * DISCLAIMER: The authors of this code have used their                   *
 * best efforts in preparing the code. These efforts include the          *
 * development, research, and testing of the theories and programs        *
 * to determine their effectiveness. The authors and publisher make       *
 * no warranty of any kind, expressed or implied, with regard to these    *
 * programs or to the documentation contained in these codes. The authors *
 * shall not be liable in any event for incidental or consequential       *
 * damages in connection with, or arising out of, the furnishing,         *
 * performance, or use of these programs.                                 *
 **************************************************************************/
%>