利用 Java 2D 绘制饼图

<%@ page language="java" contentType="image/png;charset=GBK" pageEncoding="GBK"   import="java.awt.*, javax.imageio.*,java.awt.geom.*,java.awt.image.*"%>    <%!// 绘制饼图的说明        public void drawTips(String tips, Color color, Arc2D.Double arc2d, Graphics2D g2d) {            Arc2D.Double position = arc2d;            position.setAngleExtent(arc2d.getAngleExtent() / 2);            position.x = arc2d.x - 15;            position.y = arc2d.y - 15;            position.width = arc2d.getWidth() + 50;            position.height = arc2d.getHeight() + 50;            Point2D.Double endPoint = (Point2D.Double) position.getEndPoint();            g2d.setPaint(color);            int stringLength = g2d.getFontMetrics().stringWidth(tips);            if (endPoint.x <= arc2d.getCenterX())                g2d.drawString(tips, (float) endPoint.x - stringLength,                (float) endPoint.y);            else {                g2d.drawString(tips, (float) endPoint.x, (float) endPoint.y);          }        }  %>    <%      // 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(252, 197,        113), width / 2, height / 2, new Color(255, 255, 169), true);        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);        // 绘制图表标题      //String chartTitle = "客户构成分析";        g2d.setColor(Color.BLACK);        g2d.setFont(new Font("宋体", Font.PLAIN, 30));        //int stringLength = g2d.getFontMetrics().stringWidth(chartTitle);        //g2d.drawString(chartTitle, (width - stringLength) / 2, 30);        // 定义圆弧      Arc2D.Double arc2d = new Arc2D.Double();        double startAngle = 30.0, arcAngle = 0.0;        double rectWidth = 295.0, rectHeight = 245.0;        Point2D.Double p2d = new Point2D.Double((width - rectWidth) / 2, 70.0);        int arcType = Arc2D.PIE;        Color color[] = new Color[5];        color[0] = new Color(99, 99, 0);        color[1] = new Color(255, 169, 66);        color[2] = new Color(33, 255, 66);        color[3] = new Color(33, 0, 255);        color[4] = new Color(255, 0, 66);        double bookSales[] = new double[5];        double totalSales = 0.0;        // 定义厚度      int thickness = 25;        for (int i = 0; i < bookSales.length; i++) {            bookSales[i] = 1 + Math.random() * 99;            totalSales += bookSales[i];        }        // 绘制起始角度不大于90度的圆弧      startAngle = 30;        for (int i = 0; i < bookSales.length; i++) {            arcAngle = bookSales[i];            if (startAngle >= 90) {                break;            }            for (int j = thickness; j > 0; j--) {                g2d.setColor(color[i].darker());                arc2d = new Arc2D.Double(p2d.x, p2d.y + j, rectWidth,                rectHeight, startAngle, arcAngle, arcType);                // 填充圆弧              g2d.fill(arc2d);            }            // 更新圆弧的起始角度          startAngle += arcAngle;        }        // 绘制起始角度不小于270度的圆弧      startAngle = 390;        for (int i = bookSales.length - 1; i > 0; i--) {            arcAngle = bookSales[i];            if (startAngle <= 270) {                break;            }            for (int j = thickness; j > 0; j--) {                g2d.setColor(color[i].darker());                arc2d = new Arc2D.Double(p2d.x, p2d.y + j, rectWidth,                rectHeight, startAngle, -arcAngle, arcType);                // 填充圆弧              g2d.fill(arc2d);            }            // 更新圆弧的起始角度          startAngle -= arcAngle;        }        // 绘制起始角度在90度到270度之间的圆弧      startAngle = 30;        for (int i = 0; i < bookSales.length; i++) {            arcAngle = bookSales[i];            if (startAngle > 90 && startAngle < 270) {                for (int j = thickness; j > 0; j--) {                    g2d.setColor(color[i].darker());                    arc2d = new Arc2D.Double(p2d.x, p2d.y + j, rectWidth,                    rectHeight, startAngle + arcAngle, -arcAngle,                    arcType);                    // 填充圆弧                  g2d.fill(arc2d);                }            }            // 更新圆弧的起始角度          startAngle += arcAngle;        }        // 绘制最上面一层圆弧      startAngle = 30;        for (int i = 0; i < bookSales.length; i++) {            arcAngle = bookSales[i];//item.getPercent() * 3.6;            g2d.setColor(color[i]);            arc2d = new Arc2D.Double(p2d.x, p2d.y, rectWidth, rectHeight,            startAngle, arcAngle, arcType);            // 填充圆弧          g2d.fill(arc2d);            // 描绘圆弧轮廓          g2d.setStroke(new BasicStroke(1.2f));            g2d.setPaint(Color.GRAY);            g2d.draw(arc2d);            // 更新圆弧的起始角度          startAngle += arcAngle;            g2d.setFont(new Font("宋体", Font.PLAIN, 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();           out.clear();     out = pageContext.pushBody();  %>