javaWeb图片验证码代码

1. [代码]初始粗糙代码

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.servlet.ServletException;

import javax.servlet.ServletOutputStream;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import com.sun.image.codec.jpeg.*;

/**

 * 验证码图片生成Servlet类，直接调用该Servlet即可使用

 * 取值的时候调用session.getAttribute("code")得到生成的值

 * @author <a href="mailto:weijunqiang2010@gmail.com">Ajunboys</a>

 *

 */

@WebServlet("/safecode")

public class SafeCodeImageServlet extends HttpServlet {

    private static final long serialVersionUID = 1L;

    private Color getRandColor(int fc, int bc) {// 给定范围获得随机颜色

        Random random = new Random();

        if (fc > 255)

            fc = 255;

        if (fc < 0)

            fc = 0;

        if (bc > 255)

            bc = 255;

        if (bc < 0)

            bc = 0;

        int r = fc + random.nextInt(bc - fc);

        int g = fc + random.nextInt(bc - fc);

        int b = fc + random.nextInt(bc - fc);

        return new Color(r, g, b);

    }

    @Override

    protected void service(HttpServletRequest request,

            HttpServletResponse response) throws ServletException, IOException {

        // 设置输出

        response.setContentType("image/jpeg");

        int width = 80;

        int height = 30;

        // 产生随机数

        Random r = new Random();

        // 把随机数绘制成图像

        BufferedImage imgbuf = new BufferedImage(width, height,

                BufferedImage.TYPE_INT_RGB);// 产生缓冲图像,80宽30高

        Graphics2D g = imgbuf.createGraphics();// 取得缓冲的绘制环境

        // 开始绘制

        g.setColor(getRandColor(200, 250));// 设定背景色

        g.fillRect(0, 0, width, height);// 矩形图

        // 随机产生155条干扰线，使图象中的认证码不易被其它程序探测到

        g.setColor(getRandColor(160, 200));

        for (int i = 0; i < 155; i++) {

            int x = r.nextInt(width);

            int y = r.nextInt(height);

            int xl = r.nextInt(12);

            int yl = r.nextInt(12);

            g.drawLine(x, y, x + xl, y + yl);

        }

        g.setColor(getRandColor(120, 240));

        // 随机产生100个干扰点，使图像中的验证码不易被其他分析程序探测到

        for (int i = 0; i < 100; i++) {

            int x = r.nextInt(width);

            int y = r.nextInt(height);

            g.drawOval(x, y, 0, 0);

        }

        g.setFont(new Font("Times New Roman", Font.PLAIN, 26));

        String scode = "";

        for (int i = 0; i < 4; i++) {

//            String rand = String.valueOf(r.nextInt(10));

            String rand = randomCode();

            scode += rand;

            g.setColor(new Color(20 + r.nextInt(110), 20 + r.nextInt(110),

                    20 + r.nextInt(110)));

            // 调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成

            g.drawString(rand+" ", (0==i) ? 12 : (12 * (i+1)+5), 23);

        }

        request.getSession().setAttribute("safecode", scode);

        // 输出图像

        ServletOutputStream out = response.getOutputStream();// 得到HTTP的流

        // JPEGCodec.createJPEGEncoder(out);转码

        JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);// 产生JPEG的图像加码器

        encoder.encode(imgbuf);

        out.flush();

    }

    private static String randomCode(){

        char[] dictionary = {

                '2','3','4','5','6','7','8','9'

                ,'a','b','c','d','e','f','g','h','i','j'

                ,'k','m','n','p','q','r','s','t'

                ,'u','v','w','x','y','z'

                ,'A','B','C','D','E','F','G','H','J'

                ,'K','L','M','N','P','Q','R','S','T'

                ,'U','V','W','X','Y','Z'

                /*'1','l','0','O','o','#','@','$','%','&','(',')','|','/','*'//暂时不用特殊字符(包括：数字1,0；字母：l,o,O)

                ,'^','!','~','\\'*/

                };

        StringBuffer code = new StringBuffer();

        Random r = new Random();

        code.append(dictionary[r.nextInt(dictionary.length)]);

        return code.toString();

    }

}

2. [代码]优化后的全代码

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.servlet.ServletException;

import javax.servlet.ServletOutputStream;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import com.sun.image.codec.jpeg.JPEGCodec;

import com.sun.image.codec.jpeg.JPEGImageEncoder;

/**

 * 验证码图片生成Servlet类，直接调用该Servlet即可使用

 * 取值的时候调用session.getAttribute("code")得到生成的值

 * @author <a href="mailto:weijunqiang2010@gmail.com">Ajunboys</a>

 *

 */

@WebServlet("/safecode")

public class SafeCodeImageServlet extends HttpServlet {

    private static final long serialVersionUID = 1L;

    static final char[] dictionary = {

            '2','3','4','5','6','7','8','9'

            ,'a','b','c','d','e','f','g','h','i','j'

            ,'k','m','n','p','q','r','s','t'

            ,'u','v','w','x','y','z'

            ,'A','B','C','D','E','F','G','H','J'

            ,'K','L','M','N','P','Q','R','S','T'

            ,'U','V','W','X','Y','Z'

            /*'1','l','0','O','o','#','@','$','%','&','(',')','|','/','*'//暂时不用特殊字符(包括：数字1,0；字母：l,o,O)

            ,'^','!','~','\\'*/

            };

    static Random random = new Random();

    /**

     * 产生n[4,4+]个随机数

     * @param n

     * @return

     */

    static String getRandomString(int n){

        StringBuffer buffer = new StringBuffer();

        if (n < 4) {

            n = 4;

        }

        for (int i = 0; i < n; i++) {

            buffer.append(dictionary[random.nextInt(dictionary.length)]);

        }

        return buffer.toString();

    }

    /**

     * 随机颜色

     * @return

     */

    static Color getRandomColor(){

        return new Color(random.nextInt(255), random.nextInt(255), random.nextInt(255));

    }

    /**

     * 颜色反色

     * @param c

     * @return

     */

    static Color getReverseColor(Color c){

        return new Color(255 - c.getRed(), 255 - c.getGreen(), 255 - c.getBlue());

    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        doPost(request, response);

    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        response.setContentType("image/jpeg");

        String randomString = getRandomString(6);

        request.getSession(true).setAttribute("code", randomString);

        int width = 100; //验证码图片宽度

        int height = 30; //验证码图片高度

        Color color = getRandomColor();

        Color reverse = getReverseColor(color);

        //创建一个彩图

        BufferedImage bi = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

        //绘图对象

        Graphics2D g = bi.createGraphics();

        g.setFont(new Font(Font.SANS_SERIF, Font.BOLD, 16));

        g.setColor(color);

        g.fillRect(0, 0, width, height);

        g.setColor(reverse);

        g.drawString(randomString, 18, 20);

        //绘制最多100个噪音点

        for (int i = 0, n = random.nextInt(100); i < n; i++) {

            g.drawRect(random.nextInt(width), random.nextInt(height), 1, 1);

        }

        ServletOutputStream out = response.getOutputStream();

        JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);

        encoder.encode(bi);

        out.flush();

        out.close();

    }

}

巴特西

javaWeb图片验证码代码

1. [代码]初始粗糙代码

2. [代码]优化后的全代码

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