利用 Java 2D 画曲线图
jopen
12年前
<%@ page language="java" contentType="image/jpeg;charset=GBK" import="java.awt.*, java.awt.image.*, com.sun.image.codec.jpeg.*"%> <% // 在內存中创建图像 int width = 600; int height = 500; BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); // 绘制图像 Graphics g = image.getGraphics(); Graphics2D g2d = (Graphics2D) g; // 背景色 g.setColor(new Color(240, 249, 255)); g.fillRect(0, 0, width, height); // 字体颜色 g.setColor(Color.BLACK); g.setFont(new Font("宋体", Font.PLAIN, 22)); g.drawString("新浪网2007年上半年访问量统计", 15, 25); int visit[] = new int[6]; for (int i = 0; i < visit.length; i++) { visit[i] = 1 + (int) (Math.random() * 100); } String mongth[] = { "1月", "2月", "3月", "4月", "5月", "6月" }; g.setFont(new Font("宋体", Font.BOLD, 16)); g.drawString("访问量（单位：万次）", 20, 50); g.drawString("月份", 550, 465); g.setFont(new Font("SanSSerif", Font.PLAIN, 12)); int visitValue = 0; //画横线 for (int i = 418; i > 0; i -= 38) { g.setColor(Color.BLACK); g.drawString("" + visitValue, 36, (i + 27)); g.setColor(Color.LIGHT_GRAY); g.drawLine(80, (i + 27), 520, (i + 27)); visitValue += 10; } g.setColor(Color.BLACK); g.drawLine(80, 40, 80, 445); g.drawLine(80, 445, 550, 445); int drawHigh[] = new int[mongth.length]; int drawwidth[] = new int[mongth.length]; //折点坐标 for (int i = 0; i < mongth.length; i++) { drawHigh[i] = 445 - (int) (Math.ceil(visit[i] * 3.8)); drawwidth[i] = 110 + i * 80; g.drawString(mongth[i], 110 + i * 80, 465); } //g2d.setXORMode(Color.WHITE); //折线粗细 g2d.setStroke(new BasicStroke(3.0f)); //折线的颜色 g2d.setPaint(Color.RED); //画折线 g2d.drawPolyline(drawwidth, drawHigh, mongth.length); // 产生图像 g.dispose(); ServletOutputStream sos = response.getOutputStream(); JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(sos); encoder.encode(image); out.clear(); out = pageContext.pushBody(); %>
转自：http://www.cnblogs.com/190196539/archive/2011/12/21/2295358.html