pear.jsp

提供 精通Java Web动态图表编程 一书的源代码, 大家赶快下载呀

<!--
	Fig. 7.12_01: pear.jsp
	功能: 基于Java2D的Web图表实例15: 梨子的画法，Area的布尔运算示例
-->
<%@ page language="java" contentType="image/png;charset=GB2312"
	import="java.awt.*"
	import="javax.imageio.*"
	import="java.awt.geom.*"
	import="java.awt.image.*"
	import="java.awt.font.*"
%>

<%
		// 清空缓冲区
		response.reset();

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

		// 创建一个 500X375 的图像
		int width = 500, height = 375;

		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.setColor(Color.BLACK);

		Ellipse2D.Double circle, oval, leaf, stem; 
		Area circ, ov, leaf1, leaf2, st1, st2; 
		circle = new Ellipse2D.Double(); 
		oval = new Ellipse2D.Double(); 
		leaf = new Ellipse2D.Double();
		stem = new Ellipse2D.Double(); 
		circ = new Area(circle); 
		ov = new Area(oval); 
		leaf1 = new Area(leaf); 
		leaf2 = new Area(leaf); 
		st1 = new Area(stem); 
		st2 = new Area(stem); 
		
		double x = 100 , y = 100; 
		
		// 绘制第一片叶子
		leaf.setFrame(x - 16, y - 29, 15.0, 15.0); 
		leaf1 = new Area(leaf);
		leaf.setFrame(x - 14, y - 47, 30.0, 30.0); 
		leaf2 = new Area(leaf); 
		leaf1.intersect(leaf2);
		g2d.setColor(Color.GREEN);
		g2d.fill(leaf1); 

		// 绘制第二片叶子 
		leaf.setFrame(x + 1, y - 29, 15.0, 15.0); 
		leaf1 = new Area(leaf); 
		leaf2.intersect(leaf1); 
		g2d.fill(leaf2);
		
		// 绘制茎
		stem.setFrame(x, y - 42, 40.0, 40.0); 
		st1 = new Area(stem); 
		stem.setFrame(x + 3, y - 47, 50.0, 50.0); 
		st2 = new Area(stem);
		st1.subtract(st2); 
		g2d.setColor(Color.BLACK); 
		g2d.fill(st1); 
		
		// 绘制梨子主体部分
		circle.setFrame(x - 25, y , 50.0, 50.0); 
		oval.setFrame(x - 19, y - 20, 40.0, 70.0); 
		circ = new Area(circle); 
		ov = new Area(oval); 
		circ.add(ov); 
		g2d.setColor(Color.YELLOW);
		g2d.fill(circ); 

		// 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.                                 *
 **************************************************************************/
 %>