vbarchart.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. 7.5_04_02: vBarChart.jsp
	功能: 基于Java2D的Web图表实例4: 垂直立方图
-->
<%@ page language="java" contentType="image/png;charset=GB2312"
	import="java.awt.*"
	import="javax.imageio.*"
	import="java.awt.geom.*"
	import="java.awt.image.*"
	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 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();

// 填充整个背景
g2d.setPaint(Color.WHITE);
g2d.fillRect(0, 0, width, height);

// 绘制阴影，由灰色渐进圆角矩形组成
GradientPaint grayGP = new GradientPaint(0, 0, Color.GRAY, 
	width, height, new Color(218, 214, 212), false);
g2d.setPaint(grayGP);
RoundRectangle2D.Float bgRR = 
	new RoundRectangle2D.Float(5, 5, width-5, height-5 , 50, 50);
g2d.fill(bgRR);

// 绘制渐进蓝色圆角矩形背景
GradientPaint blueGP = new GradientPaint(0, 0, new Color(14, 97, 147), 
	0, height, new  Color(240, 243, 247), false);
g2d.setPaint(blueGP);
g2d.fillRoundRect(0, 0, width - 5, height - 5, 50, 50);

// 绘制深蓝色圆角矩形轮廓
BasicStroke bs = new BasicStroke(1.2f);
g2d.setStroke(bs);
g2d.setPaint(new Color(55,71, 105));
g2d.drawRoundRect(0, 0, width -5, height -5, 50, 50);

// 绘制图表绘图区域背景的阴影效果
Rectangle2D.Float drawArea =
	new Rectangle2D.Float(63, 48, 400, 300);
g2d.setPaint(Color.GRAY);
g2d.fill(drawArea);

// 填充图表绘图区域背景
g2d.setPaint(Color.WHITE);
drawArea = new Rectangle2D.Float(60,45, 400, 300);
g2d.fill(drawArea);

// 描绘图表绘图区域的轮廓
g2d.setPaint(Color.BLACK);
g2d.draw(drawArea);

// 绘制图表标题
String chartTitle = "计算机编程类图书2004年月销售量统计图";
g2d.setFont(new Font("华文隶书", Font.PLAIN, 25));
int stringLength = g2d.getFontMetrics().stringWidth(chartTitle);

g2d.setColor(Color.WHITE);
g2d.drawString(chartTitle, (width - stringLength) / 2, 25 );

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

String str = "";
stringLength = 0;
g2d.setPaint(Color.BLACK);
g2d.setFont(new Font("宋体", Font.PLAIN, 12));
for (int i = 1; i <= 12; i++)
{
  // 绘制垂直方向虚线
  g2d.drawLine(60+i * 400/13, 45, 60+i * 400/13, 345);

  // 绘制横轴上月份的说明文字
  str += i + "月";
  stringLength = g2d.getFontMetrics().stringWidth(str);
  g2d.drawString(str, 60+i * 400/13 - stringLength / 2, 360);
  
  // 重置月份说明文字
  str = "";
}

g2d.setFont(new Font("Arial", Font.BOLD, 14));
str = "";
int stringHeight = 0;

for (int i = 0; i <= 300; i += 30)
{
  // 绘制水平方向虚线
  g2d.drawLine(60, 45+i, 460, 45+i);

  // 绘制纵轴上销售量的说明文字
  str += 100-i / 3;
  stringHeight = g2d.getFontMetrics().getAscent();
  stringLength = g2d.getFontMetrics().stringWidth(str);
  g2d.drawString(str, 55-stringLength, 45+i + stringHeight / 2);
  str = "";
}

String[] bookTitle = { "JAVA", "C#" };
Color[] bookColor = {new Color(230,111, 71) , new Color(107,165,239)};
double[] sales = new double[12];
int[] month = new int[12];

g2d.setFont(new Font("Courier New", Font.PLAIN, 12));
g2d.setStroke(new BasicStroke());
Rectangle2D.Double bar ; 	

for (int i = 0; i < bookTitle.length; i++)
{ 
  // 初始化绘制数据
  double bookSales = 0.0;

  for (int j = 0; j < sales.length; j++)
  {
    bookSales = 1 + Math.random() * 295;
    sales[j] = 345 - bookSales ;
    month[j] = 60+ ((j+1) * 400)/13;
	bar = new Rectangle2D.Double(month[j]-6 + i *10,
		sales[j]+2, 10, bookSales-2);
	
	// 填充直方图阴影
	g2d.setPaint(Color.GRAY);
	g2d.fill(bar);

	bar = new Rectangle2D.Double(month[j]-10 + i *10,
		sales[j], 10, bookSales);
	GradientPaint drawGP = new GradientPaint(month[j]-10 + i *10,
		(int)sales[j], bookColor[i], month[j]-10 + i *10, 345, 
		bookColor[i].brighter(), false);
    
	// 填充直方图
	g2d.setPaint(drawGP);
	g2d.fill(bar);

	// 描绘直方图轮廓
	g2d.setPaint(Color.BLACK);
	g2d.draw(bar);
  }

  // 绘制图例
  g2d.setColor(bookColor[i]);
  g2d.fillRect(418, 50+i * 12, 10, 10);
  g2d.setColor(Color.BLACK);
  g2d.drawString(bookTitle[i], 432, 60+i * 12);
}

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