java 生成验证码，java验证码,/** * */pac

java 生成验证码，java验证码,/** * */pac

/** *  */package com.becom.dkyd.webapp.util;import java.awt.Color;import java.awt.Font;import java.awt.Graphics2D;import java.awt.image.BufferedImage;import java.io.IOException;import java.util.Random;import javax.imageio.ImageIO;import javax.servlet.ServletException;import javax.servlet.ServletOutputStream;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;import com.becom.dkyd.common.Constant;public class RandomCodeServlet extends HttpServlet{    /**     * serialVersionUID     */    private static final long serialVersionUID = 5916019367240722024L;    private int width = 60;    private int height = 20;    @Override    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException    {        BufferedImage img = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);        Graphics2D g = img.createGraphics();        Random random = new Random();        g.setColor(Color.WHITE);        g.fillRect(0, 0, width, height);        Font font = new Font("Times New Roman", Font.PLAIN, 18);        g.setFont(font);        // 边框        g.setColor(Color.BLACK);        g.drawRect(0, 0, width - 1, height - 1);        // 干扰线        g.setColor(Color.GRAY);        for (int i = 0; i < 60; i++)        {            int x = random.nextInt(width);            int y = random.nextInt(height);            int x1 = random.nextInt(12);            int y1 = random.nextInt(12);            g.drawLine(x, y, x + x1, y + y1);        }        // 保存验证码        StringBuffer randomCode = new StringBuffer();        int red = 0;        int green = 0;        int blue = 0;        // 生成验证码        for (int i = 0; i < 4; i++)        {        String strRand = String.valueOf(random.nextInt(10));            red = random.nextInt(110);            green = random.nextInt(50);            blue = random.nextInt(50);            g.setColor(new Color(red, green, blue));            g.drawString(strRand, 13 * i + 6, 16);            randomCode.append(strRand);        }        // 验证码放入session中        HttpSession session = req.getSession();        //需要验证的地方        //加入session        // 禁止图象缓存        resp.setHeader("Pragma", "no-cache");        resp.setHeader("Cache-Control", "no-cache");        resp.setDateHeader("Expires", 0);        resp.setContentType("image/jpeg");        // 输出图象        ServletOutputStream sos = resp.getOutputStream();        ImageIO.write(img, "jpeg", sos);        sos.close();    }}