Java生成图片验证码

素颜马尾好姑娘i 2022-06-07 08:39 388阅读 0赞

功能介绍：自定义图片尺寸和字符长度，随机背景颜色和字符颜色，随机字符偏移角度，字符平滑边缘，干扰线，噪点，背景扭曲。

VerifyCodeUtils类，生成图片流，然后不同框架下的输出可以参考上面的代码或者自行百度，无非就是获取outputStream和ContentType的区别，main方法可直接执行:

这里写图片描述

  1. package edu.xt.utils;
  3. import java.awt.Color;
  4. import java.awt.Font;
  5. import java.awt.Graphics;
  6. import java.awt.Graphics2D;
  7. import java.awt.RenderingHints;
  8. import java.awt.geom.AffineTransform;
  9. import java.awt.image.BufferedImage;
  10. import java.io.File;
  11. import java.io.FileOutputStream;
  12. import java.io.IOException;
  13. import java.io.OutputStream;
  14. import java.util.Arrays;
  15. import java.util.Random;
  17. import javax.imageio.ImageIO;
  19. /** * * <p>Title:VerifyCodeUtils </p> * <p>Description: 生成图片流核心代码块</p> * <p>Company: </p> * @author 小桃小涛 * @date 2017年10月15日下午2:45:57 */
  20. public class VerifyCodeUtils { 
  21.     //去掉了1,0,i,o几个容易混淆的字符
  22.     public static final String VERIFYCODES="23456789ABCDEFGHJKLMNPQRSTUVWXYZ";
  23.     private static Random random = new Random();
  24.     /** * @使用系统默认字符源生成验证码 * @param verifySize 验证码长度 * @return */
  25.     public static String generateVerifyCode(int verifySize){
  26.         return generateVerifyCode(verifySize,VERIFYCODES);
  27.     }
  28.     /** * @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 */
  29.     public static String generateVerifyCode(int verifySize,String sources){
  30.         //判断是否有字符源
  31.         if(sources==null||sources.length()==0){
  32.             sources=VERIFYCODES;
  33.         }
  34.         int CodeLen = sources.length();
  35.         Random random = new Random(System.currentTimeMillis());
  36.         StringBuilder verifyCode = new StringBuilder(verifySize);  
  37.         for(int i=0;i<verifySize;i++){
  38.             verifyCode.append(sources.charAt(random.nextInt(CodeLen-1)));
  39.         }
  40.         return verifyCode.toString();
  41.     }
  42.     /** * @生成随机验证码文件 并返回验证码值 * @param width * @param height * @param outputFile * @param verifySize * @return * @throws IOException */
  43.     public static String outputVerifyImage(int width,int height,File outputFile,int verifySize) throws IOException{
  44.         String verifyCode = generateVerifyCode(verifySize);
  45.         outputImage(width, height, outputFile, verifyCode);
  46.         return verifyCode;
  47.     }
  48.     public static void outputImage(int width,int height,File outputFile, String code) throws IOException{
  49.         if(outputFile==null){
  50.             return;
  51.         }
  52.         File dir = outputFile.getParentFile();
  53.         if(!dir.exists()){
  54.             dir.mkdirs();
  55.         }
  56.         try{
  57.             outputFile.createNewFile();
  58.             FileOutputStream fos = new FileOutputStream(outputFile);
  59.             outputImage(width, height, fos, code);
  60.             fos.close();
  61.         }catch(IOException e){
  62.             throw e;//手动抛出IOException 异常
  63.         }
  64.     }
  65.     public static void outputImage(int width,int height,OutputStream os,String code) throws IOException{
  66.         int verifySize = code.length();
  67.         //创建一个画板
  68.         BufferedImage buf =new BufferedImage(width, height, BufferedImage.TYPE_INT_BGR);
  69.         Random random = new Random();
  70.         //创建一个绘图工具
  71.         Graphics2D gs= buf.createGraphics();
  72.         //消除线段的锯齿状边缘
  73.         gs.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
  74.         //创建颜色集合
  75.         Color[] colors = new Color[5];
  76.         Color[] colorSpaces = new Color[]{
  77.                 Color.WHITE, Color.CYAN,  
  78.                 Color.GRAY, Color.LIGHT_GRAY, 
  79.                 Color.MAGENTA, Color.ORANGE,  
  80.                 Color.PINK, Color.YELLOW 
  81.         };
  82.         Float[] fractions = new Float[colors.length];
  83.         for(int i=0;i<colors.length;i++){
  84.             colors[i]=colorSpaces[random.nextInt(colorSpaces.length)];
  85.             fractions[i]=random.nextFloat();
  86.         }
  87.         Arrays.sort(fractions);//排序
  89.         //设置边框色
  90.         gs.setColor(Color.GRAY);
  91.         gs.fillRect(0, 0, width, height);
  93.         Color c= getRandomColor(200, 500);
  94.         gs.setColor(c);
  95.         gs.fillRect(0, 2, width, height-4);
  97.         //绘制干扰线
  98.         Random rand = new Random();
  99.         gs.setColor(getRandomColor(160, 200));
  100.         for(int i=0;i<20;i++){
  101.             int x=rand.nextInt(width-1);
  102.             int y= rand.nextInt(height-1);
  103.             int x1=rand.nextInt(6)+1;
  104.             int y1 = rand.nextInt(12)+1;
  105.             gs.drawLine(x, y, x+x1+40, y+y1+20);
  106.         }
  108.         //添加噪点
  109.         float yawpRate =0.05f;//噪点率
  110.         int area = (int)(yawpRate*width*height);
  111.         for(int i=0;i<area;i++){
  112.             int x=random.nextInt(width);
  113.             int y=random.nextInt(height);
  114.             int rgb = getRandomIntColor();
  115.             buf.setRGB(x, y, rgb);
  116.         }
  117.         //使图片扭曲
  118.         shear(gs,width,height,c);
  120.         gs.setColor(getRandomColor(100, 160));
  121.         int fontSize=height-4;
  122.         Font font = new Font("Algerian",Font.ITALIC,fontSize);
  123.         gs.setFont(font);
  124.         char[] chars = code.toCharArray();
  125.         for(int i=0;i<verifySize;i++){
  126.              AffineTransform affine = new AffineTransform();  
  127.              affine.setToRotation(Math.PI / 4 * rand.nextDouble() * (rand.nextBoolean() ? 1 : -1), (width/ verifySize) * i + fontSize/2, height/2);  
  128.              gs.setTransform(affine);  
  129.              gs.drawChars(chars, i, 1, ((width-10) / verifySize) * i + 5, height/2 + fontSize/2 - 10);  
  130.         }
  131.         gs.dispose();  
  132.         ImageIO.write(buf, "JPEG", os);
  133.     }
  134.     /** * @rgb颜色的区域是0~255 * @param fc * @param bc * @return */
  135.     private static Color getRandomColor(int fc,int bc){
  136.         if(fc>255) fc=255;
  137.         if(bc>255) bc=255;
  138.         int r=fc+random.nextInt(bc-fc);
  139.         int g=fc+random.nextInt(bc-fc);
  140.         int b=fc+random.nextInt(bc-fc);
  141.         return new Color(r,g,b);
  142.     }
  143.     private static int getRandomIntColor(){
  144.         int[] rgb = getRandomRgb();
  145.         int color=0;
  146.         for (int c : rgb) {
  147.             color=color<<8;
  148.             color=color|c;
  149.         }
  150.         return color;
  151.     }
  152.     private static int[] getRandomRgb(){
  153.         int[] rgb = new int[3];
  154.         for(int i=0;i<3;i++){
  155.             rgb[i]=random.nextInt(255);
  156.         }
  157.         return rgb;
  158.     }
  159.     private static void shear(Graphics g,int w ,int h,Color color){
  160.         shearX(g,w,h,color);
  161.         shearY(g,w,h,color);
  162.     } 
  163.     private static void shearX(Graphics g,int w ,int h,Color color){
  164.         int period = random.nextInt(2);
  166.         boolean borderGap =true;
  167.         int frames =1;
  168.         int phase = random.nextInt(2);
  169.         for(int i=0;i<h;i++){
  170.             //???????
  171.             double d = (double) (period >> 1)  
  172.                     * Math.sin((double) i / (double) period  
  173.                             + (6.2831853071795862D * (double) phase)  
  174.                             / (double) frames);  
  175.              g.copyArea(0, i, w, 1, (int) d, 0);  
  176.              if(borderGap){
  177.                  g.setColor(color);
  178.                  g.drawLine((int)d, i, 0, i);
  179.                  g.drawLine((int)d+w, i, w, i);
  180.              }
  181.         }
  182.     }
  183.      private static void shearY(Graphics g, int w, int h, Color color) {  
  184.             int period = random.nextInt(40) + 10; // 50; 
  186.             boolean borderGap = true;  
  187.             int frames = 20;  
  188.             int phase = 7;  
  189.             for (int i = 0; i < w; i++) {  
  190.                 double d = (double) (period >> 1)  
  191.                         * Math.sin((double) i / (double) period  
  192.                                 + (6.2831853071795862D * (double) phase)  
  193.                                 / (double) frames);  
  194.                 g.copyArea(i, 0, 1, h, 0, (int) d);  
  195.                 if (borderGap) {  
  196.                     g.setColor(color);  
  197.                     g.drawLine(i, (int) d, i, 0);  
  198.                     g.drawLine(i, (int) d + h, i, h);  
  199.                 }  
  200.             }  
  201.         } 
  203.      public static void main(String[] args){
  204.          File dir = new File("D:/学习文档/验证码/verify");
  205.          int width=200,height=80;
  206.              String verifyCode = generateVerifyCode(4);
  207.              File file = new File(dir,verifyCode+".jpg");
  208.              try {
  209.                 outputImage(width, height, file, verifyCode);
  210.             } catch (IOException e) {
  211.                 e.printStackTrace();
  212.             }
  213.      }
  214. }

AuthImage类

  1. package edu.xt.utils;
  3. import java.io.IOException;
  5. import javax.servlet.http.HttpServletRequest;
  6. import javax.servlet.http.HttpServletResponse;
  7. import javax.servlet.http.HttpSession;
  8. public class AuthImage extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet{ 
  9.     private static final long serialVersionUID = 1L;
  10.     public void service(HttpServletRequest request, HttpServletResponse response) throws IOException{
  11.         response.setHeader("Pragma", "No-cache");  
  12.         response.setHeader("Cache-Control", "no-cache");  
  13.         response.setDateHeader("Expires", 0);  
  14.         response.setContentType("image/jpeg");  
  16.         //生成随机字符串
  17.         String verifyCode = VerifyCodeUtils.generateVerifyCode(4);
  18.         //存入会话 session
  19.         HttpSession session = request.getSession(true);
  20.         //删除以前的
  21.         session.removeAttribute("rand");
  22.         session.setAttribute("rand", verifyCode.toString());
  23.         //生成图片
  24.         int w=200,h=60;
  25.         VerifyCodeUtils.outputImage(w, h, response.getOutputStream(), verifyCode);
  26.     }
  27. }

xml配置文件

  1. <?xml version="1.0" encoding="UTF-8"?>
  2. <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
  3.   <display-name>VerifyCode</display-name>
  4.   <servlet>
  5.     <servlet-name>AuthImage</servlet-name>
  6.     <servlet-class>edu.xt.utils.AuthImage</servlet-class>
  7.   </servlet>
  8.   <servlet-mapping>
  9.     <servlet-name>AuthImage</servlet-name>
  10.     <url-pattern>/authImage</url-pattern>
  11.   </servlet-mapping>
  12.   <welcome-file-list>
  13.     <welcome-file>index.html</welcome-file>
  14.     <welcome-file>index.htm</welcome-file>
  15.     <welcome-file>index.jsp</welcome-file>
  16.     <welcome-file>default.html</welcome-file>
  17.     <welcome-file>default.htm</welcome-file>
  18.     <welcome-file>default.jsp</welcome-file>
  19.   </welcome-file-list>
  21. </web-app>

最后界面效果
这里写图片描述

  1. <%@ page language="java" pageEncoding="UTF-8"%>
  2. <!doctype html>
  3. <html>
  4.  <head>
  5.   <meta charset="UTF-8">
  6.   <meta name="Keywords" content="关键字、关键词">
  7.   <meta name="Description" content="描述语句">
  8.   <title>VerifyCode验证码</title>
  10.  </head>
  11.  <body>
  12.   <table>
  13.     <tr>
  14.    <td nowrap width="437"></td>
  15.     <td>
  16.         <img id="img" src="authImage" />
  17.         <a href='#' onclick="javascript:changeImage()"><label>看不清？</label></a>
  18.     </td>
  19.  </tr>
  20.  </table>
  23.   <script type="text/javascript" src="js/jquery-3.1.0.js"></script>
  24.   <script type="text/javascript"> function changeImage(){ var img = document.getElementById("img"); img.src = "authImage?date=" + new Date(); } </script>
  25.  </body>
  26. </html>

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