关于java生成验证码

待我称王封你为后i 2022-05-21 11:34 222阅读 0赞

一.读取外部txt文件生成二维码

jsp:

<%@ page language="java" contentType="text/html; charset=UTF-8"  
    pageEncoding="UTF-8"%>  
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">  
<html>  
<head>  
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">  
<title>验证码生成</title>  
<script type="text/javascript" src="$\{pageContext.request.contextPath\}/js/jquery-1.7.2.js"></script>  
<script type="text/javascript">    
  function myReload() \{    
    document.getElementById("CreateCheckCode").src =     
        document.getElementById("CreateCheckCode").src+ "?nocache=" + new Date().getTime();    
  \}    
</script>    
</head>  
<body>  
      <p style="margin-left:40%;color:blue;">验证码生成</p>  
      <div style="margin-left:30%;margin-top:5%">  
   <form action="$\{pageContext.request.contextPath\}/loginServlet" method="post">  
               验证码：<input type="text" name = "checkCode" style="width:80px;height:35px;"/>                 
              
                 
       <img src="$\{pageContext.request.contextPath\}/phraseCode" id="CreateCheckCode" align="middle"   
               style="margin-top:-10px;"> <br/>   
                 
       <a href="" οnclick="myReload()"   
               style="font-size:12px;color:red;margin-left:156px;">  
                                   看不清,换一个</a> <br/>         
       <input type="submit" value="Submit"   
               style="width:240px;height:35px;background:\#f19e28"/>  
   </form>  
      </div>  
</body>

</html>

后台部分：

1.处理登陆请求

package com.imgcode;  
  
  
import java.io.IOException;  
import javax.servlet.ServletException;  
import javax.servlet.annotation.WebServlet;  
import javax.servlet.http.HttpServlet;  
import javax.servlet.http.HttpServletRequest;  
import javax.servlet.http.HttpServletResponse;  
import javax.servlet.http.HttpSession;  
  
  
/\*\*  
 \* 处理登录请求  
 \*/  
@WebServlet("/loginServlet")  
public class ImgCode extends HttpServlet \{  
private static final long serialVersionUID = 1L;  
         
      
    public ImgCode() \{  
        super();     
    \}  
  
  
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException \{  
this.doPost(request, response);  
\}  
  
  
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException \{  
request.setCharacterEncoding("utf-8");  
response.setContentType("text/html");  
response.setCharacterEncoding("utf-8");  
String code = request.getParameter("checkCode");  
HttpSession session = request.getSession();  
if(!code.equalsIgnoreCase((String)session.getAttribute("randCheckCode")))\{  
request.setAttribute("errormsg", "验证码不正确");  
response.getWriter().print("<script> type='text/javascript'>window.alert('\*验证码错误！');window.location.href='jsp/imgCode.jsp'</script>");  
\}  
response.getWriter().println("<script> type='text/javascript'>window.alert('\*验证码校验成功！');window.location.href='jsp/imgCode.jsp'</script>");    
     response.getWriter().print("验证码校验成功");        
       
\}

2.  验证码生成类

说明：外部txt文件里面时存放的四字成语，成语的个数一定要大于随机读取成语的数字，及对应的randomChar（）方法里面

的参数num的值；

package com.imgcode;  
  
import java.awt.BasicStroke;  
import java.awt.Color;  
import java.awt.Font;  
import java.awt.Graphics;  
import java.awt.Graphics2D;  
import java.awt.geom.AffineTransform;  
import java.awt.geom.Line2D;  
import java.awt.image.BufferedImage;  
import java.io.IOException;  
import java.util.List;  
import java.util.Random;  
import javax.imageio.ImageIO;  
import javax.servlet.ServletException;  
import javax.servlet.annotation.WebServlet;  
import javax.servlet.http.HttpServlet;  
import javax.servlet.http.HttpServletRequest;  
import javax.servlet.http.HttpServletResponse;  
import javax.servlet.http.HttpSession;  
  
  
/\*\*  
 \* 验证码-- 成语验证  
 \*/  
@WebServlet("/phraseCode")  
public class PhraseCode extends HttpServlet \{  
private static final long serialVersionUID = 1L;  
  
public PhraseCode() \{  
super();  
\}  
  
  
/\*\*  
\* @Title: getRandom   
\* @Description: 该方法主要作用是获得随机生成的颜色  
\* @param @param s  
\* @param @param e  
\* @param @return    设定文件   
\* @return Color    返回类型   
\* @throws  
\*/  
public Color getRandColor(int s,int e)\{  
Random random = new Random();  
if(s > 255)\{  
s = 255;  
\}  
if(e > 255)\{  
e = 255;  
\}  
int r,g,b;  
r = s + random.nextInt(e - s);  
g = s + random.nextInt(e - s);  
b = s + random.nextInt(e - s);  
return new Color(r,g,b);  
\}  
  
          
//读取code验证码文件  
//验证码为txt成语文件  
private String randomChar()\{  
List<String> fileList = FileUtils.getFile(null);  
//List<String> asList = Arrays.asList(code);  
Random ran = new Random();  
int num = ran.nextInt(149);//随机定位个数并读取相应位置的成语  
System.out.println(num);  
String codes = fileList.get(num);  
return codes;  
\}  
  
  
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException \{  
this.doPost(request, response);  
\}  
  
  
//doPost方法  
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException \{  
request.setCharacterEncoding("utf-8");  
response.setCharacterEncoding("utf-8");  
  
  
//设置不缓存图片  
response.setHeader("Pragma", "No-cache");  
response.setHeader("Cache-Control", "No-cache");  
response.setDateHeader("Expires", 0);    
  
  
//指定生成的响应图片，一定不能缺少这句话,否则错误.    
response.setContentType("image/jepg");  
//制定生成验证码的宽度和高度  
int width = 80;  
int height = 35;  
  
  
// 创建BufferedImage对象,其作用相当于一图片  
BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE\_INT\_RGB);  
// 创建Graphics对象,其作用相当于画笔    
Graphics g = image.getGraphics();  
// 创建Grapchics2D对象   
Graphics2D g2d = (Graphics2D) g;  
  
  
Random random = new Random();  
//定义字体样式  
Font font = new Font("楷体", Font.BOLD, 16);  
g.setColor(getRandColor(200,250));  
// 绘制背景    
g.fillRect(0, 0, width, height);  
//设置字体  
g.setFont(font);  
g.setColor(getRandColor(180, 200));   
  
  
// 绘制100条颜色和位置全部为随机产生的线条,该线条为2f    
for (int i = 0; i < 100; i++) \{    
int x = random.nextInt(width - 1);    
int y = random.nextInt(height - 1);    
int x1 = random.nextInt(6) + 1;    
int y1 = random.nextInt(12) + 1;    
BasicStroke bs = new BasicStroke(2f, BasicStroke.CAP\_BUTT, BasicStroke.JOIN\_BEVEL);   
  
  
//定制线条样式  
Line2D line = new Line2D.Double(x,y,x+x1,y+y1);  
g2d.setStroke(bs);  
g2d.draw(line);  
\}  
  
  
  
  
//用来保存验证码字符串文本内容    
StringBuilder sb = new StringBuilder();  
//验证码为txt成语文件时  
String sTemp = String.valueOf(randomChar());  
sb.append(sTemp);  
Color color = new Color(20 + random.nextInt(110),  
20 + random.nextInt(110),random.nextInt(110));  
g.setColor(color);  
  
  
// 将生成的随机数进行随机缩放并旋转制定角度 PS.  
// 建议不要对文字进行缩放与旋转,因为这样图片可能不正常显示   
  
  
//将文字旋转制定角度  
Graphics2D g2d\_word = (Graphics2D) g;    
AffineTransform trans = new AffineTransform();    
//trans.rotate((22) \* 3.14 / 180, 15 + 8, 1);   
  
  
//说明：rotate(\[angle\] \[px,py\])  
// \[angle\] : 旋转角度。 由于屏幕坐标和数学坐标的Y轴相反，所以向左旋转为正角度值。  
// \[px,py\] : 旋转的中心点。参数缺省默认为圆点（0,0）。  
trans.rotate(10\*Math.PI/180);    
  
  
// 缩放文字    
float scaleSize = random.nextFloat() + 1f;    
if (scaleSize > 1f)    
scaleSize = 1f;    
trans.scale(scaleSize, scaleSize);    
g2d\_word.setTransform(trans);    
g.drawString(sTemp,10, 14); //说明drawString（取到的值,距离左边，距离上边）  
  
  
HttpSession session = request.getSession(true);  
session.setAttribute("randCheckCode", sb.substring(0, 4).toString());  
System.out.println("随机验证码="+sb.substring(0, 4).toString());  
// 释放g所占用的系统资源    
g.dispose();   
// 输出图片    
ImageIO.write(image, "JPEG", response.getOutputStream());   
\}

3.工具类，读取外部txt文件

package com.imgcode;  
  
  
import java.io.BufferedReader;  
import java.io.File;  
import java.io.FileNotFoundException;  
import java.io.FileReader;  
import java.io.IOException;  
import java.util.ArrayList;  
import java.util.List;  
import javax.servlet.http.HttpServletRequest;  
  
  
/\*\*   
 \* @ClassName: FileUtils   
 \* @Description: 读取文本验证码文件  
 \* @author lhz  
 \* @date 2018年6月21日 上午12:33:46   
 \*/  
public class FileUtils\{  
  
public static List<String> getFile(HttpServletRequest request)\{  
  
  
FileReader fis = null;  
BufferedReader bis = null;  
String str = null;  
  
try \{  
List<String> list = new ArrayList<String>();  
File file  = new File("F:/eclipsework/video/src/com/imgcode/code.txt");  
fis = new FileReader(file);  
bis = new BufferedReader(fis);  
  
  
  
while((str = bis.readLine()) != null)\{  
String\[\] split = str.split(",");  
for(int i = 0;i < split.length;i++)\{  
list.add(split\[i\]);  
\}  
\}  
return list;  
\} catch (FileNotFoundException e) \{  
e.printStackTrace();  
\} catch (IOException e) \{  
e.printStackTrace();  
\}finally\{  
if(bis != null)\{  
try \{  
bis.close();  
\} catch (IOException e) \{  
e.printStackTrace();  
\}  
\}  
  
if(fis != null)\{  
try \{  
fis.close();  
\} catch (IOException e) \{  
e.printStackTrace();  
\}  
\}  
\}  
return null;  
\}

生成后效果：

![70][]

二.生成数字+字母大小写组合的验证码

jsp:

<%@ page language="java" contentType="text/html; charset=UTF-8"  
    pageEncoding="UTF-8"%>  
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">  
<html>  
<head>  
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">  
<title>验证码生成</title>  
<script type="text/javascript" src="$\{pageContext.request.contextPath\}/js/jquery-1.7.2.js"></script>  
<script type="text/javascript">    
  function myReload() \{    
    document.getElementById("CreateCheckCode").src =     
        document.getElementById("CreateCheckCode").src+ "?nocache=" + new Date().getTime();    
  \}    
</script>    
</head>  
<body>  
      <p style="margin-left:40%;color:blue;">验证码生成</p>  
      <div style="margin-left:30%;margin-top:5%">  
   <form action="$\{pageContext.request.contextPath\}/loginServlet" method="post">  
               验证码：<input type="text" name = "checkCode" style="width:80px;height:35px;"/>  
                 
                 
       - <img src="$\{pageContext.request.contextPath\}/pictureCheckCode" id="CreateCheckCode"         align="middle"  style="margin-top:-10px;"> <br/>                                 
       <a href="" οnclick="myReload()"   
               style="font-size:12px;color:red;margin-left:156px;">  
                                   看不清,换一个</a> <br/>         
       <input type="submit" value="Submit"   
               style="width:240px;height:35px;background:\#f19e28"/>  
   </form>  
      </div>  
</body>  
</html>

后台部分：

1.处理登录请求：

package com.imgcode;  
  
  
import java.io.IOException;  
import javax.servlet.ServletException;  
import javax.servlet.annotation.WebServlet;  
import javax.servlet.http.HttpServlet;  
import javax.servlet.http.HttpServletRequest;  
import javax.servlet.http.HttpServletResponse;  
import javax.servlet.http.HttpSession;  
  
  
/\*\*  
 \* 处理登录请求  
 \*/  
@WebServlet("/loginServlet")  
public class ImgCode extends HttpServlet \{  
private static final long serialVersionUID = 1L;  
         
      
    public ImgCode() \{  
        super();  
    \}  
  
  
//doGet  
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException \{  
this.doPost(request, response);  
\}  
  
  
//doPost  
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException \{  
request.setCharacterEncoding("utf-8");  
response.setContentType("text/html");  
response.setCharacterEncoding("utf-8");  
String code = request.getParameter("checkCode");  
HttpSession session = request.getSession();  
if(!code.equalsIgnoreCase((String)session.getAttribute("randCheckCode")))\{  
request.setAttribute("errormsg", "验证码不正确");  
response.getWriter().print("<script> type='text/javascript'>window.alert('\*验证码错误！');window.location.href='jsp/imgCode.jsp'</script>");  
\}  
response.getWriter().println("<script> type='text/javascript'>window.alert('\*验证码校验成功！');window.location.href='jsp/imgCode.jsp'</script>");    
     response.getWriter().print("验证码校验成功");            
       
\}

2.验证码生成类

package com.imgcode;  
  
  
import java.awt.BasicStroke;  
import java.awt.Color;  
import java.awt.Font;  
import java.awt.Graphics;  
import java.awt.Graphics2D;  
import java.awt.geom.AffineTransform;  
import java.awt.geom.Line2D;  
import java.awt.image.BufferedImage;  
import java.io.IOException;  
import java.util.Random;  
import javax.imageio.ImageIO;  
import javax.servlet.ServletException;  
import javax.servlet.annotation.WebServlet;  
import javax.servlet.http.HttpServlet;  
import javax.servlet.http.HttpServletRequest;  
import javax.servlet.http.HttpServletResponse;  
import javax.servlet.http.HttpSession;  
  
  
/\*\*  
 \* 验证码生成 包括：字母 + 数字   
 \* private String codes = "23456789abcdefghijkmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYXZ";  
 \*   
 \*/  
@WebServlet("/pictureCheckCode")  
public class PictureCheckCode extends HttpServlet \{  
private static final long serialVersionUID = 1L;  
  
  
  
public PictureCheckCode() \{  
super();  
\}  
  
  
/\*\*  
\* @Title: getRandom   
\* @Description: 该方法主要作用是获得随机生成的颜色  
\* @param @param s  
\* @param @param e  
\* @param @return    设定文件   
\* @return Color    返回类型   
\* @throws  
\*/  
public Color getRandColor(int s,int e)\{  
Random random = new Random();  
if(s > 255)\{  
s = 255;  
\}  
if(e > 255)\{  
e = 255;  
\}  
int r,g,b;  
r = s + random.nextInt(e - s);  
g = s + random.nextInt(e - s);  
b = s + random.nextInt(e - s);  
return new Color(r,g,b);  
\}  
  
  
private Random r = new Random();  
// 随机字符集合中不包括0和o，O，1和l，因为这些不易区分     
private String codes = "23456789abcdefghijkmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYXZ";  
  
//验证码code为随机字母+数子时：  
private char randomChar()\{  
int index = r.nextInt(codes.length());  
return codes.charAt(index);  
\}  
  
  
//doGet  
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException \{  
this.doPost(request, response);  
\}  
  
  
//doPost  
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException \{  
request.setCharacterEncoding("utf-8");  
response.setCharacterEncoding("utf-8");  
  
  
//设置不缓存图片  
response.setHeader("Pragma", "No-cache");  
response.setHeader("Cache-Control", "No-cache");  
response.setDateHeader("Expires", 0);    
  
  
//指定生成的响应图片，一定不能缺少这句话,否则错误.    
response.setContentType("image/jepg");  
//制定生成验证码的宽度和高度  
int width = 80;  
int height = 35;  
  
  
// 创建BufferedImage对象,其作用相当于一图片  
BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE\_INT\_RGB);  
// 创建Graphics对象,其作用相当于画笔    
Graphics g = image.getGraphics();  
// 创建Grapchics2D对象   
Graphics2D g2d = (Graphics2D) g;  
  
  
Random random = new Random();  
//定义字体样式  
Font font = new Font("楷体", Font.BOLD, 16);  
g.setColor(getRandColor(200,250));  
// 绘制背景    
g.fillRect(0, 0, width, height);  
//设置字体  
g.setFont(font);  
g.setColor(getRandColor(180, 200));   
  
  
// 绘制100条颜色和位置全部为随机产生的线条,该线条为2f    
for (int i = 0; i < 100; i++) \{    
int x = random.nextInt(width - 1);    
int y = random.nextInt(height - 1);    
int x1 = random.nextInt(6) + 1;    
int y1 = random.nextInt(12) + 1;    
BasicStroke bs = new BasicStroke(2f, BasicStroke.CAP\_BUTT, BasicStroke.JOIN\_BEVEL);   
  
  
//定制线条样式  
Line2D line = new Line2D.Double(x,y,x+x1,y+y1);  
g2d.setStroke(bs);  
g2d.draw(line);  
\}  
  
  
  
  
//用来保存验证码字符串文本内容    
StringBuilder sb = new StringBuilder();  
//随机生成4个数字 ----code是字母+数字组合式  
for(int i = 0;i<4;i++)\{  
String sTemp = String.valueOf(randomChar());  
sb.append(sTemp);  
Color color = new Color(20 + random.nextInt(110),  
20 + random.nextInt(110),random.nextInt(110));  
g.setColor(color);  
  
  
// 将生成的随机数进行随机缩放并旋转制定角度 PS.  
// 建议不要对文字进行缩放与旋转,因为这样图片可能不正常显示   
  
  
//将文字旋转制定角度  
Graphics2D g2d\_word = (Graphics2D) g;    
AffineTransform trans = new AffineTransform();    
trans.rotate((45) \* 3.14 / 180, 15 \* i + 8, 7);    
  
  
// 缩放文字    
float scaleSize = random.nextFloat() + 0.8f;    
if (scaleSize > 1f)    
scaleSize = 1f;    
trans.scale(scaleSize, scaleSize);    
g2d\_word.setTransform(trans);    
g.drawString(sTemp, 15 \* i + 18, 14);    
\}  
  
  
  
  
HttpSession session = request.getSession(true);  
//验证码为字母 + 数字 组合式：  
session.setAttribute("randCheckCode", sb.toString());  
System.out.println("随机验证码="+sb.toString());  
// 释放g所占用的系统资源    
g.dispose();   
// 输出图片    
    ImageIO.write(image, "JPEG", response.getOutputStream());   
\}  
\}

生成后效果：

![70 1][]

[70]: /images/20220521/deaeb51fd0b44677afd797b89b353cba.png
[70 1]: /images/20220521/e7854dca838e4d939ce9e9cb560f3247.png