验证码 随机旋转、字体、颜色
package servlet;import java.awt.BasicStroke;import java.awt.Color;import java.awt.Font;import java.awt.Graphics;import java.awt.Graphics2D;import java.awt.GraphicsEnvironment;import java.awt.geom.AffineTransform;import java.awt.image.BufferedImage;import java.io.IOException;import java.util.Random;import javax.imageio.ImageIO;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;public class SecurityCodeServlet extends HttpServlet {private Color getRandColor(int s, int e) {Random random = new Random();if (s > 255)s = 255;if (e > 255)e = 255;int r = random.nextInt(e - s) + s; // 随机生成RGB中的R值int g = random.nextInt(e - s) + s; // 随机生成RGB中的G值int b = random.nextInt(e - s) + s; // 随机生成RGB中的B值return new Color(r, g, b);}public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {this.doPost(request, response);}public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {response.setHeader("Pragma", "No-cache");response.setHeader("Cache-Control", "No-cache");response.setDateHeader("Expires", 0);//指定生成的响应图片response.setContentType("image/jpeg");int width = 150;//指定生成验证码图片的宽度int heigh = 60;//指定生成验证码图片的高度//获得图像数据缓冲对象BufferedImage bi = new BufferedImage(width,heigh,BufferedImage.TYPE_INT_RGB);//获得图形上下文的抽象基类Graphics g = bi.getGraphics();Random r = new Random();Font f = new Font("黑体",Font.PLAIN,60);//定义字体样式g.setColor(getRandColor(200, 250));//设置背景颜色g.fillRect(0, 0, width, heigh);//绘制背景g.setFont(f);//设置字体g.setColor(getRandColor(180, 200));//设置前景颜色Graphics2D g2d = (Graphics2D) g;//画一条折线BasicStroke bs=new BasicStroke(5f,BasicStroke.CAP_BUTT,BasicStroke.JOIN_BEVEL);//创建一个供画笔选择线条粗细的对象g2d.setStroke(bs);//改变线条的粗细g2d.setColor(Color.DARK_GRAY);//设置当前颜色为预定义颜色中的深灰色int[] xPoints=new int[8];int[] yPoints=new int[8];for(int j=0;j<8;j++){xPoints[j]=r.nextInt(width - 1);yPoints[j]=r.nextInt(heigh - 1);}g2d.drawPolyline(xPoints, yPoints,8);String sRand = "";String ctmp = "";int itmp = 0;for (int i = 0; i < 6; i++) {switch (r.nextInt(2)) {case 1:itmp = r.nextInt(26) + 65; // 生成A~Z的字母ctmp = String.valueOf((char) itmp);break;default:itmp = r.nextInt(10) + 48; // 生成0~9的数字ctmp = String.valueOf((char) itmp);break;}sRand += ctmp;//设置每个字符的随机颜色Color color = new Color(20 + r.nextInt(210), 20 + r.nextInt(210), 20 + r.nextInt(210));g2d.setColor(color);//设置每个字符的随机字体g2d.setFont(this.getRandomFont());//设置每个字符的随机旋转AffineTransform at = new AffineTransform();int number = r.nextInt(3)-1;double role = number*r.nextDouble()*(Math.PI/4);at.setToRotation(role,25*i+5,55-r.nextInt(20)); //role:旋转角度,后面两个参数是设置围绕坐标点旋转g2d.setTransform(at);g2d.drawString(ctmp, 25*i+5,55-r.nextInt(20));}HttpSession session = request.getSession(true);session.setMaxInactiveInterval(5*60);//设置session对象5分钟失效session.setAttribute("code", sRand.toString());g2d.dispose();System.out.println(sRand);ImageIO.write(bi, "JPEG", response.getOutputStream());} public static Font getRandomFont() { //String[] fonts = {"Georgia", "Verdana", "Arial", "Tahoma", "Time News Roman", "Courier New", "Arial Black", "Quantzite"}; String[] fonts = {"a_TrianglerCmUp","Astarisborn","WishfulWaves"}; Random r = new Random(); int fontIndex = r.nextInt(fonts.length); return new Font(fonts[fontIndex], r.nextInt(3),50-r.nextInt(20)); }}把字体加入到操作系统中