loadimage.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. 6.04_09: loadImage.jsp
	功能:加载并显示图像
-->
<%@ page language="java" contentType="image/png;charset=GB2312"
	import="java.awt.image.*"
	import="java.awt.*"
	import="javax.imageio.*"
	import="java.io.*"
%>

<%
		// 清空缓冲区
		response.reset();

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

		// 创建一个 640X480 的图像
		int width = 640, height = 480;

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

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

        g.setColor(Color.BLACK);

		// 设置标题
        g.setFont(new Font("汉真广标", Font.PLAIN, 35));
        g.drawString("图像文件的加载与显示", 10, 35);

		Image logoJPG, logoBMP, logoPNG, logoGIF;
        
		File pngFile = 
			new File(getServletContext().getRealPath("images\\logo.png"));
		File jpgFile = 
			new File(getServletContext().getRealPath("images\\logo.jpg"));
		File gifFile = 
			new File(getServletContext().getRealPath("images\\logo.gif"));
		File bmpFile = 
			new File(getServletContext().getRealPath("images\\logo.bmp"));

        // 加载并显示图像
		logoPNG = ImageIO.read(pngFile);
		g.drawImage(logoPNG, 10, 50, null);

		logoJPG = ImageIO.read(jpgFile);
		g.drawImage(logoJPG, 10, 200, null);

		logoGIF = ImageIO.read(gifFile);
		g.drawImage(logoGIF, 210, 50, null);

		logoBMP = ImageIO.read(bmpFile);
		g.drawImage(logoBMP, 210, 200, null);

		// 部署图形
		g.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.                                 *
 **************************************************************************/

%>