JSP随机验证图片如何制作分享

  package icewee.image;    import java.awt.BasicStroke;  import java.awt.Color;  import java.awt.Font;  import java.awt.Graphics2D;  import java.awt.RenderingHints;  import java.awt.geom.Line2D;  import java.awt.image.BufferedImage;  import java.util.Random;    public class TokenUtil {    private static final String base = "23456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefhijklmnpqrstuvwxyz";    private static final int length = base.length();      public static BufferedImage createTokenImage(int width, int height,        String randomCode) {      BufferedImage image = new BufferedImage(width, height,          BufferedImage.TYPE_INT_RGB);      Graphics2D g = image.createGraphics();      Random random = new Random();      g.setColor(new Color(230, 230, 250)); // 设置背景色      g.fillRect(0, 0, width, height); // 填充背景      g.setColor(Color.BLACK);      // 绘制边缘      g.drawRect(-1, -1, width + 1, height + 1);      g.setColor(Color.GRAY);      // 设置字体,随机选择字体,暂设置8种字体      Font font = new Font((new String[] { "Arial", "Arial Black",          "Arial Italic", "Courier New", "Courier New Bold Italic",          "Courier New Italic", "Franklin Gothic Medium",          "Franklin Gothic Medium Italic" })[random.nextInt(8)],          Font.PLAIN, 30);      // g.setStroke(new BasicStroke((float)(Math.random()),      // BasicStroke.CAP_BUTT, BasicStroke.JOIN_BEVEL));      g.setFont(font);      // 定义字体颜色范围      int red = random.nextInt(160), green = random.nextInt(50), blue = random          .nextInt(50);      // 定义一个无干扰线区间和一个起始位置      int nor = random.nextInt(50), rsta = random.nextInt(131);      // 绘制干扰正弦曲线 M:曲线平折度, D:Y轴常量 V:X轴焦距      int M = random.nextInt(15) + 5, D = random.nextInt(23) + 15, V = random          .nextInt(5) + 1;      double x = 0.0;      double y = M * Math.sin(Math.toRadians(V * x)) + D;      double px, py;      for (int i = 0; i < 131; i++) {        px = x + 1;        py = M * Math.sin(Math.toRadians(V * px)) + D;        if (rsta < i && i < (rsta + nor))          g.setColor(new Color(230, 230, 250));        else          g.setColor(new Color(red, green, blue));        // 随机设置像素点宽带(线宽)        g.setStroke(new BasicStroke((float) (Math.random() + 1.5f)));        g.draw(new Line2D.Double(x, y, px, py));        x = px;        y = py;      }      char[] codes = randomCode.toCharArray();      for (int i = 0; i < codes.length; i++) {        // 旋转图形        int degree = (random.nextInt(20) - 10) % 360;        double ang = degree * 0.0174532925; // 将角度转为弧度        g.rotate(ang, width / 2, height / 2);        g.setColor(new Color(red, green, blue));        g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,            RenderingHints.VALUE_ANTIALIAS_ON);        int gr = random.nextInt(8);        g.drawString(String.valueOf(codes[i]), 24 * i + 10 + gr, 38);      }      g.dispose();      return image;    }      public static String createRandomCode(int size, int width, int height) {      StringBuffer randomCode = new StringBuffer();      for (int i = 0; i < size; i++) {        Random random = new Random();        int start = random.nextInt(length);        String strRand = base.substring(start, start + 1);        randomCode.append(strRand);      }      return randomCode.toString();    }  }  

  <%@ page contentType="image/jpeg" pageEncoding="GBK"%>  <%@ page import="java.awt.image.BufferedImage" %>  <%@page import="javax.imageio.ImageIO" %>  <%@ page import="com.icesoft.image.TokenUtil" %>    <%    //设置页面不缓存    response.setHeader("Pragma", "No-cache");    response.setHeader("Cache-Control", "no-cache");    response.setDateHeader("Expires", 0);    int width = 120, height = 50;    String randomCode = TokenUtil.createRandomCode(4, width, height);    System.out.println("生成的随机码：" + randomCode);    BufferedImage image = TokenUtil.createTokenImage(width, height, randomCode);    ImageIO.write(image, "JPEG", response.getOutputStream());    response.flushBuffer();    out.clear();    out = pageContext.pushBody();  %>