Java实现验证码具体代码

Z时代
2024-01-10
分类：IT

这里实现我使用到了struts2模拟一个登录功能来验证java实现的验证码功能。

Java实现验证码的步骤：

1、创建RandomImageGenerator.java类，该类实现验证码图片的生成

2、创建一个servlet类，RandomImageServlet.java，将生成的验证码输出到页面

3、创建一个Action类，LoginAction.java，控制登录

4、配置struts.xml一个web.xml文件

5、编写页面

具体实现用代码表达

1、创建RandomImageGenerator.java类

代码如下:

package com.tenghu.code;

import java.awt.Color;import java.awt.Font;import java.awt.Graphics2D;import java.awt.image.BufferedImage;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import java.io.OutputStream;import java.util.Random;import javax.imageio.ImageIO;

/** * 验证码生成类 * @author xiaohu * */public class RandomImageGenerator { //创建Random对象 static Random random=new Random(); //随机生成包含验证码字符串 public static String random(int num){ //初始化种子 String[] str={"0","1","2","3","4","5","6","7","8","9", "a","b","c","d","e","f","g","h","i","j", "k","l","m","n","p","q","r","s","t"}; int number=str.length; //接收随机字符 String text = ""; //随机产生4个字符的字符串 for(int i=0;i<num;i++){ text+=str[random.nextInt(number)]; } return text; } /** * 随机产生定义的颜色 * * @return */ private static Color getRandColor() { Random random = new Random(); Color color[] = new Color[10]; color[0] = new Color(32, 158, 25); color[1] = new Color(218, 42, 19); color[2] = new Color(31, 75, 208); color[3] = new Color(0, 102, 182); color[4] = new Color(171, 0, 85); return color[random.nextInt(5)]; } /** * 产生随机字体 * * @return */ private static Font getFont() { Random random = new Random(); Font font[] = new Font[5]; font[0] = new Font("Ravie", Font.BOLD, 30); font[1] = new Font("Antique Olive Compact", Font.BOLD, 30); font[2] = new Font("Forte", Font.BOLD, 30); font[3] = new Font("Wide Latin", Font.BOLD, 30); font[4] = new Font("Gill Sans Ultra Bold", Font.BOLD, 30); return font[random.nextInt(5)]; } /** * 生成图片 * @throws IOException */ public static void render(String randomStr,OutputStream out,int width,int height) throws IOException{ //在内存中创建图像 BufferedImage bi=new BufferedImage(width, height, BufferedImage.TYPE_BYTE_INDEXED); //获取图形上下文 Graphics2D g=(Graphics2D) bi.getGraphics(); //话边框 g.setColor(Color.white); g.fillRect(0, 0, width, height); g.setFont(getFont()); g.setColor(Color.BLACK); //画认证码，每个认证码在不同的水平位置 String str1[]=new String[randomStr.length()]; for(int i=0;i<str1.length;i++){ str1[i]=randomStr.substring(i,i+1); int w=0; int x=(i+1)%3; //随机生成验证码字符水平偏移量 if(x==random.nextInt(7)){ w=30-random.nextInt(7); }else{ w=30+random.nextInt(7); } //随机生成颜色 g.setColor(getRandColor()); g.drawString(str1[i], 20*i+10, w); } //随机产生干扰点，并用不同的颜色表示，事图像的认证码不易被其他程序探测到 for(int i=0;i<100;i++){ int x=random.nextInt(width); int y=random.nextInt(height); Color color=new Color(random.nextInt(255), random.nextInt(255), random.nextInt(255)); //随机画各种颜色的线 g.setColor(color); g.drawOval(x, y, 0, 0); } //画干扰线 for(int i=0;i<15;i++){ int x=random.nextInt(width); int y=random.nextInt(height); int x1=random.nextInt(width); int y1=random.nextInt(height); Color color=new Color(random.nextInt(255), random.nextInt(255), random.nextInt(255)); //随机画各种颜色线 g.setColor(color); g.drawLine(x, y, x1, y1); } //图像生效 g.dispose(); //输出页面 ImageIO.write(bi, "jpg", out); } public static void main(String[] args) throws FileNotFoundException, IOException { //获取随机字符串 String randomStr=random(5); System.out.println(randomStr); //生成图片 render(randomStr, new FileOutputStream("D:\\test.jpg"),130,40); }}

2、创建RandomImageServlet.java

代码如下:

package com.tenghu.code.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.tenghu.code.RandomImageGenerator;

public class RandomImageServlet extends HttpServlet { //图片宽度 int width=0; //图片高度 int height=0; //图片上随机字符个数 int randomStrNum=0; public void destroy() { } public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("UTF-8"); //获取HttpSession对象 HttpSession session=request.getSession(); //获取随机字符串 String randomStr=RandomImageGenerator.random(randomStrNum); if(null!=session){ //设置参数 session.setAttribute("randomStr", randomStr); //设置响应类型,输出图片客户端不缓存 response.setDateHeader("Expires", 1L); response.setHeader("Cache-Control", "no-cache, no-store, max-age=0"); response.addHeader("Pragma", "no-cache"); response.setContentType("image/jpeg"); //输出到页面 RandomImageGenerator.render(randomStr, response.getOutputStream(), width, height); } } public void init() throws ServletException { //获取宽度 width=Integer.parseInt(this.getInitParameter("width")); //获取高度 height=Integer.parseInt(this.getInitParameter("height")); //获取个数 randomStrNum=Integer.parseInt(this.getInitParameter("num")); }}

3、创建LoginAction.java类

代码如下:

package com.tenghu.code.action;

import java.io.ByteArrayInputStream;import java.io.InputStream;import com.opensymphony.xwork2.ActionContext;import com.opensymphony.xwork2.ActionSupport;

public class LoginAction extends ActionSupport{ //用户名 private String userName; //密码 private String password; //验证码 private String code; private InputStream inputStream; public InputStream getResult(){ return inputStream; } //成功 public String success() throws Exception{ return SUCCESS; } //测试登录 public String testLogin() throws Exception{ //获取图片的验证码 String randomStr=(String) ActionContext.getContext().getSession().get("randomStr"); if(code.trim().equalsIgnoreCase(randomStr)){ if("admin".equals(userName.trim())&&"admin".equals(password.trim())){ //成功 inputStream=new ByteArrayInputStream("1".getBytes("UTF-8")); }else{ //用户名或密码错误 inputStream=new ByteArrayInputStream("2".getBytes("UTF-8")); } }else{ //验证码错误 inputStream=new ByteArrayInputStream("0".getBytes("UTF-8")); } return "result"; } public String getUserName() { return userName; } public void setUserName(String userName) { this.userName = userName; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public String getCode() { return code; } public void setCode(String code) { this.code = code; }}

4、配置struts.xml、web.xml文件

代码如下:

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN" "http://struts.apache.org/dtds/struts-2.3.dtd"><struts>  <package name="installs" extends="struts-default">  <action name="login" class="com.tenghu.code.action.LoginAction">   <!-- 登录成功到success.jsp页面 -->   <result name="success">success.jsp</result>   <!-- 登录验证返回的数据 -->   <result name="result" type="stream">    <param name="contentType">text/html</param>    <param name="inputName">result</param>   </result>  </action> </package></struts>

代码如下:

<?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>RandomImageServlet</servlet-name>    <servlet-class>com.tenghu.code.servlet.RandomImageServlet</servlet-class>    <!-- 初始化图片宽度 -->    <init-param>     <param-name>width</param-name>     <param-value>130</param-value>    </init-param>    <!-- 初始化图片高度 -->    <init-param>     <param-name>height</param-name>     <param-value>40</param-value>    </init-param>    <!-- 初始化图片随机数个数 -->    <init-param>     <param-name>num</param-name>     <param-value>4</param-value>    </init-param>  </servlet>

<servlet-mapping> <servlet-name>RandomImageServlet</servlet-name> <url-pattern>/verification.do</url-pattern> </servlet-mapping>  <filter> <filter-name>struts2</filter-name> <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class> </filter> <filter-mapping> <filter-name>struts2</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list></web-app>

5、编写测试页面

代码如下:

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>    <base href="<%=basePath%>">    <title>My JSP 'index.jsp' starting page</title> <script type="text/javascript" src="js/jquery-1.10.2.min.js"></script> <script type="text/javascript" src="js/jquery.form.js"></script> <script type="text/javascript">  $(document).ready(function(){   CODE.initCode();   //验证输入   function checkInput(){    if($('#userName').val()==''){     alert('用户名不能为空！');     return false;    }    if($('#password').val()==''){     alert('密码不能为空！');     return false;    }    if($('#code').val()==''){     alert('验证码不能为空！');     return false;    }    return true;   }   //点击按钮   $('#btn').click(function(){    if(checkInput()==true){     $('#login_request').ajaxSubmit({      url:'login!testLogin',      cache:false,      type:'POST',      success:function(data){       if(data==0){        alert('验证码错误！');        //改变验证码        CODE.initCode();       }else if(data==1){        alert('登录成功！');        //提交到登录成功页面        $('#login_request')[0].submit();       }else if(data==2){        alert('用户名或密码错误！');        //改变验证码        CODE.initCode();       }      },      error:function(e){       alert('出错了！');      }     });     }   });  });  var CODE={    //初始化化验证码    initCode:function(){     $("#code_img").attr("src","verification.do?rmd="+new Date().getTime())//如果需要点击图片改变图片的内容，则必须添加时间搓     .click(function(){      $(this).attr("src","verification.do?rmd="+new Date().getTime());     });     }}; </script>  </head>  <body>   <form action="login!success" id="login_request" method="post">    UserName:<input type="text" id="userName" name="userName"/><br/>    Password:<input type="password" id="password" name="password"/><br>    Verification_Code:<input type="text" id="code" name="code"/><img id="code_img" style="position:relative;top:8px;height:25px"><br>    <input type="button" id="btn" value="登录"/>   </form>  </body></html>

成功页面就部贴出来了，就是一段文字而已显示结果：