java 用Graphics制作模糊验证码

这篇随笔主要是java中制作验证码的效果，由于是在国庆前做的，现在也找不到原载了。我对自己整理的发表一份

生成的验证码效果如下：

一、建立一个工具类，用来生成验证码

 package com.dkt.util;

 import java.awt.Color;
 import java.awt.Font;
 import java.awt.Graphics;
 import java.awt.Graphics2D;
 import java.awt.RenderingHints;
 import java.awt.geom.AffineTransform;
 import java.awt.image.BufferedImage;
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.util.Arrays;
 import java.util.Random;

 import javax.imageio.ImageIO;
 /**
  * <p><b>VerifyCodeUtils Description:</b> (验证码生成)</p>
  * <b>DATE:</b> 2016年6月2日 下午3:53:34
  */
 public class VerifyCodeUtils{

     //使用到Algerian字体，系统里没有的话需要安装字体，字体只显示大写，去掉了1,0,i,o几个容易混淆的字符
     public static final String VERIFY_CODES = "23456789ABCDEFGHJKLMNPQRSTUVWXYZ";
     private static Random random = new Random();

     /**
      * 使用系统默认字符源生成验证码
      * @param verifySize    验证码长度
      * @return
      */
     public static String generateVerifyCode(int verifySize){
         return generateVerifyCode(verifySize, VERIFY_CODES);
     }
     /**
      * 使用指定源生成验证码
      * @param verifySize    验证码长度
      * @param sources   验证码字符源
      * @return
      */
     public static String generateVerifyCode(int verifySize, String sources){
         if(sources == null || sources.length() == 0){
             sources = VERIFY_CODES;
         }
         int codesLen = sources.length();
         Random rand = new Random(System.currentTimeMillis());
         StringBuilder verifyCode = new StringBuilder(verifySize);
         for(int i = 0; i < verifySize; i++){
             //随机在验证字符中取一个值
             verifyCode.append(sources.charAt(rand.nextInt(codesLen-1)));
         }
         return verifyCode.toString();//得到四位数的验证码
     }

     /**
      * 生成随机验证码文件,并返回验证码值
      * @param w
      * @param h
      * @param outputFile
      * @param verifySize
      * @return
      * @throws IOException
      */
     public static String outputVerifyImage(int w, int h, File outputFile, int verifySize) throws IOException{
         String verifyCode = generateVerifyCode(verifySize);
         outputImage(w, h, outputFile, verifyCode);
         return verifyCode;
     }

     /**
      * 输出随机验证码图片流,并返回验证码值
      * @param w
      * @param h
      * @param os
      * @param verifySize
      * @return
      * @throws IOException
      */
     public static String outputVerifyImage(int w, int h, OutputStream os, int verifySize) throws IOException{
         String verifyCode = generateVerifyCode(verifySize);
         outputImage(w, h, os, verifyCode);
         return verifyCode;
     }

     /**
      * 生成指定验证码图像文件
      * @param w
      * @param h
      * @param outputFile
      * @param code
      * @throws IOException
      */
     public static void outputImage(int w, int h, File outputFile, String code) throws IOException{
         if(outputFile == null){
             return;
         }
         File dir = outputFile.getParentFile();//文件目录
         if(!dir.exists()){
             dir.mkdirs();
         }
         try{
             outputFile.createNewFile();//创建文件
             FileOutputStream fos = new FileOutputStream(outputFile);
             outputImage(w, h, fos, code);
             fos.close();
         } catch(IOException e){
             throw e;
         }
     }

     /**
      * 输出指定验证码图片流
      * @param w  宽
      * @param h   高
      * @param os   输出流方式
      * @param code   验证码
      * @throws IOException
      */
     public static void outputImage(int w, int h, OutputStream os, String code) throws IOException{
         int verifySize = code.length();
         //类型为预定义图像类型之一的 BufferedImage。
         BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
         Random rand = new Random();
         Graphics2D g2 = image.createGraphics();
         g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
         Color[] colors = new Color[5];
         Color[] colorSpaces = new Color[] { Color.WHITE, Color.CYAN,
                 Color.GRAY, Color.LIGHT_GRAY, Color.MAGENTA, Color.ORANGE,
                 Color.PINK, Color.YELLOW };
         float[] fractions = new float[colors.length];
         for(int i = 0; i < colors.length; i++){
             colors[i] = colorSpaces[rand.nextInt(colorSpaces.length)];
             fractions[i] = rand.nextFloat();
         }
         Arrays.sort(fractions);

         g2.setColor(Color.GRAY);// 设置边框色
         g2.fillRect(0, 0, w, h);

         Color c = getRandColor(200, 250);
         g2.setColor(c);// 设置背景色
         g2.fillRect(0, 2, w, h-4);

         //绘制干扰线
         Random random = new Random();
         g2.setColor(getRandColor(160, 200));// 设置线条的颜色
         for (int i = 0; i < 20; i++) {
             int x = random.nextInt(w - 1);
             int y = random.nextInt(h - 1);
             int xl = random.nextInt(6) + 1;
             int yl = random.nextInt(12) + 1;
             g2.drawLine(x, y, x + xl + 40, y + yl + 20);
         }

         // 添加噪点
         float yawpRate = 0.05f;// 噪声率
         int area = (int) (yawpRate * w * h);
         for (int i = 0; i < area; i++) {
             int x = random.nextInt(w);
             int y = random.nextInt(h);
             int rgb = getRandomIntColor();
             image.setRGB(x, y, rgb);
         }

         shear(g2, w, h, c);// 使图片扭曲

         g2.setColor(getRandColor(100, 160));
         int fontSize = h-4;
         Font font = new Font("Algerian", Font.ITALIC, fontSize);
         g2.setFont(font);
         char[] chars = code.toCharArray();
         for(int i = 0; i < verifySize; i++){
             AffineTransform affine = new AffineTransform();
             affine.setToRotation(Math.PI / 4 * rand.nextDouble() * (rand.nextBoolean() ? 1 : -1), (w / verifySize) * i + fontSize/2, h/2);
             g2.setTransform(affine);
             g2.drawChars(chars, i, 1, ((w-10) / verifySize) * i + 5, h/2 + fontSize/2 - 10);
         }

         g2.dispose();
         ImageIO.write(image, "jpg", os);
     }

     private static Color getRandColor(int fc, int bc) {
         if (fc > 255)
             fc = 255;
         if (bc > 255)
             bc = 255;
         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);
     }

     private static int getRandomIntColor() {
         int[] rgb = getRandomRgb();
         int color = 0;
         for (int c : rgb) {
             color = color << 8;
             color = color | c;
         }
         return color;
     }

     private static int[] getRandomRgb() {
         int[] rgb = new int[3];
         for (int i = 0; i < 3; i++) {
             rgb[i] = random.nextInt(255);
         }
         return rgb;
     }

     private static void shear(Graphics g, int w1, int h1, Color color) {
         shearX(g, w1, h1, color);
         shearY(g, w1, h1, color);
     }

     private static void shearX(Graphics g, int w1, int h1, Color color) {

         int period = random.nextInt(2);

         boolean borderGap = true;
         int frames = 1;
         int phase = random.nextInt(2);

         for (int i = 0; i < h1; i++) {
             double d = (double) (period >> 1)
                     * Math.sin((double) i / (double) period
                             + (6.2831853071795862D * (double) phase)
                             / (double) frames);
             g.copyArea(0, i, w1, 1, (int) d, 0);
             if (borderGap) {
                 g.setColor(color);
                 g.drawLine((int) d, i, 0, i);
                 g.drawLine((int) d + w1, i, w1, i);
             }
         }

     }

     private static void shearY(Graphics g, int w1, int h1, Color color) {

         int period = random.nextInt(40) + 10; // 50;

         boolean borderGap = true;
         int frames = 20;
         int phase = 7;
         for (int i = 0; i < w1; i++) {
             double d = (double) (period >> 1)
                     * Math.sin((double) i / (double) period
                             + (6.2831853071795862D * (double) phase)
                             / (double) frames);
             g.copyArea(i, 0, 1, h1, 0, (int) d);
             if (borderGap) {
                 g.setColor(color);
                 g.drawLine(i, (int) d, i, 0);
                 g.drawLine(i, (int) d + h1, i, h1);
             }

         }

     }
     public static void main(String[] args) throws IOException{
         File dir = new File("e:/verifies");// 生成的验证码存放目录
         int w = 200, h = 80;

             String verifyCode = generateVerifyCode(4);
             File file = new File(dir, verifyCode + ".jpg");
             outputImage(w, h, file, verifyCode);

         /*String verifyCode = generateVerifyCode(4);
         System.out.println(verifyCode);*/

     }
 }

二、建立一个CodeEnt实体类

 package com.dkt.entity;

 public class CodeEnt {
     private String code;//验证码
     private long nowtime;//失效的毫秒时间
     public String getCode() {
         return code;
     }
     public void setCode(String code) {
         this.code = code;
     }
     public long getNowtime() {
         return nowtime;
     }
     public void setNowtime(long nowtime) {
         this.nowtime = nowtime;
     }
     public CodeEnt(String code, long nowtime) {
         super();
         this.code = code;
         this.nowtime = nowtime;
     }
     public CodeEnt() {
         super();
     }

 }

三、建立servlet类，作为服务器，调用上面的类生成验证码，并把验证码发送到页面，且验证验证码输入是否正确

我在这里为了方便理解，建立了两个servlet类，

一个类是  AuthImage 就是用来调用工具类 VerifyCodeUtils  ,生成验证码并发送到页面上

 package com.dkt.servlet;

 import java.io.IOException;

 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import javax.servlet.http.HttpSession;

 import com.dkt.entity.CodeEnt;
 import com.dkt.util.VerifyCodeUtils;

 public class AuthImage extends HttpServlet  {
     static final long serialVersionUID = 1L;
     public void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
         response.setHeader("Pragma", "No-cache"); //不缓存
         response.setHeader("Cache-Control", "no-cache");
         response.setDateHeader("Expires", 0);
         response.setContentType("image/jpeg"); //输出的图片

         //生成随机字串
         String verifyCode = VerifyCodeUtils.generateVerifyCode(4);
         //存入会话session
         HttpSession session = request.getSession();
         //保存
         long nowtime = System.currentTimeMillis();
         CodeEnt codeEnt = new CodeEnt(verifyCode, nowtime);
         session.setAttribute("codeent", codeEnt);
         //生成图片  并发送到页面中
         int w = 100, h = 30;
         VerifyCodeUtils.outputImage(w, h, response.getOutputStream(), verifyCode); 

     }
 }

另一个类是 CodeServlet 主要是判断用户输入的验证码是否正确，并给出提示

 package com.dkt.servlet;

 import java.io.IOException;
 import java.util.Calendar;

 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import javax.servlet.http.HttpSession;

 import com.dkt.entity.CodeEnt;

 public class CodeServlet extends HttpServlet {

     public void doGet(HttpServletRequest request, HttpServletResponse response)
             throws ServletException, IOException {
         doPost(request, response);
     }
     public void doPost(HttpServletRequest request, HttpServletResponse response)
             throws ServletException, IOException {

         response.setContentType("text/html");
         request.setCharacterEncoding("utf-8");
         response.setCharacterEncoding("utf-8");
         //存入会话session
         HttpSession session = request.getSession();
         String op = request.getParameter("op");
         if (("reg").equals(op)) {
             // 判断用户输入的验证是否正确且没有超时
             String code = request.getParameter("code");
             System.out.println("code--------->"+code);
             if (code!=null&&!("").equals(code)) {
                 code = code.toUpperCase();//全部转成大写字母
             }
             CodeEnt codeEnt = (CodeEnt)session.getAttribute("codeent");
             long nowT = Calendar.getInstance().getTimeInMillis();
             //System.out.println(System.currentTimeMillis());
             //System.out.println(nowT);
             long diffT = nowT-codeEnt.getNowtime();
             System.out.println("时间差："+diffT);
             if (diffT<30000) {
                 if (code.equals(codeEnt.getCode())) {
                     System.out.println("验证成功");
                     request.getRequestDispatcher("success.jsp").forward(request, response);
                 }else {
                     request.setAttribute("error", "验证码输入错误，请重新输入");
                     request.getRequestDispatcher("verify.jsp").forward(request, response);
                 }
             }else {
                 //验证不成功重新刷新验证码
                 request.setAttribute("error", "验证码失效，请重新刷新");
                 request.getRequestDispatcher("verify.jsp").forward(request, response);
             }
         }else {
             System.out.println("else");
         }

     }
 }

四，xml中的配置信息

 <?xml version="1.0" encoding="UTF-8"?>
 <web-app version="2.5"
     xmlns="http://java.sun.com/xml/ns/javaee"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
     http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
   <servlet>
     <description>This is the description of my J2EE component</description>
     <display-name>This is the display name of my J2EE component</display-name>
     <servlet-name>AuthImage</servlet-name>
     <servlet-class>com.dkt.servlet.AuthImage</servlet-class>
   </servlet>
   <servlet>
     <description>This is the description of my J2EE component</description>
     <display-name>This is the display name of my J2EE component</display-name>
     <servlet-name>CodeServlet</servlet-name>
     <servlet-class>com.dkt.servlet.CodeServlet</servlet-class>
   </servlet>

   <servlet-mapping>
     <servlet-name>AuthImage</servlet-name>
     <url-pattern>/AuthImage</url-pattern>
   </servlet-mapping>
   <servlet-mapping>
     <servlet-name>CodeServlet</servlet-name>
     <url-pattern>/CodeServlet</url-pattern>
   </servlet-mapping>
   <welcome-file-list>
     <welcome-file>verify.jsp</welcome-file>
   </welcome-file-list>
 </web-app>

五、写页面 jsp ，添加事件

 <%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
 <%
 String path = request.getContextPath();
 String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
 %>

 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
 <html>
   <head>
     <base href="<%=basePath%>">

     <title>My JSP 'verify.jsp' starting page</title>

     <meta http-equiv="pragma" content="no-cache">
     <meta http-equiv="cache-control" content="no-cache">
     <meta http-equiv="expires" content="0">
     <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
     <meta http-equiv="description" content="This is my page">
     <!--
     <link rel="stylesheet" type="text/css" href="styles.css">
     -->

 <script type="text/javascript">
         function change(img){
             img.src = img.src+"?"+new Date();
         }

 </script>
   </head>

   <body>
     <form action="CodeServlet?op=reg" method="post">
     <span style="font-size: 12px;color: red;">${error}</span><br/>
         用户名：<input type="text" name="name" value=""><br/><br/>
         验证码：<input type="text" name="code" value=""/>
         <img src="AuthImage" alt="验证码"  onclick="change(this)"/>
         <input type="submit" value="提交">
     </form>
   </body>
 </html>

五、执行结果

启动服务器，在浏览器地址栏中访问，

当输入错误时，会显示：

当输入时验证码失效时，会提示：

输入成功时会跳到  success.jsp  页面，这个页面就请大家自己随便写洛。