哈喽,大家好,我是了不起。
我们其实很经常看到,登录一些网站其实是需要验证码的。使用验证码是现在很多网站通行的一种方式,因为计算机很难识别验证码,所以可以识别验证码的用户就可以被认为是人类。
今天我们讲一下在 JAVA 中验证码的使用。
本效果是利用easy-captcha工具包实现,首先需要添加相关依赖到pom.xml中,代码如下:
<dependency>
<groupId>com.Github.whvcse</groupId>
<artifactId>easy-captcha</artifactId>
<version>1.6.2</version>
</dependency>
easy-captcha验证码工具支持GIF、中文、算术等类型,分别通过下面几个实例对象实现:
字符类型分为以下几种:
package com.yanx.controller;
import com.wf.captcha.SpecCaptcha;
import com.wf.captcha.base.Captcha;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMApping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.thymeleaf.util.StringUtils;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
@Controller
public class KapchaController {
@GetMapping("/kaptcha")
public void defaultKaptcha(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws IOException {
httpServletResponse.setHeader("Cache-Control","no-store");
httpServletResponse.setHeader("Pragma","no-cache");
httpServletResponse.setDateHeader("Expires",0);
httpServletResponse.setContentType("image/gif");
//三个参数分别为宽、高、位数
SpecCaptcha captcha=new SpecCaptcha(75,30,4);
//设置类型为数字和字母混合
captcha.setCharType(Captcha.TYPE_DEFAULT);
//设置字体
captcha.setCharType(Captcha.FONT_9);
//验证码存入session
httpServletRequest.getSession().setAttribute("verifyCode",captcha.text().toLowerCase());
//输出图片流
captcha.out(httpServletResponse.getOutputStream());
}
}
这里控制器新增了defaultKaptcha()方法,该方法所拦截处理的路径为/kaptcha
在static目录中新建kaptcha.html页面,代码如下:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>验证码</title>
</head>
<body>
<img src="/kaptcha" onclick="this.src='/kaptcha?t=new Date()'">
</body>
</html>
访问后端验证码路径/kaptcha,验证码为图片形式。onclick方法为点击该标签时可以动态切换显示验证码。
启动Spring Boot项目,打开浏览器输入地址:
http://localhost:8080/kaptcha.html
效果如下:
package com.yanx.controller;
import com.wf.captcha.SpecCaptcha;
import com.wf.captcha.base.Captcha;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.thymeleaf.util.StringUtils;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
@Controller
public class KapchaController {
@GetMapping("/kaptcha")
public void defaultKaptcha(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws IOException {
httpServletResponse.setHeader("Cache-Control","no-store");
httpServletResponse.setHeader("Pragma","no-cache");
httpServletResponse.setDateHeader("Expires",0);
httpServletResponse.setContentType("image/gif");
//三个参数分别为宽、高、位数
SpecCaptcha captcha=new SpecCaptcha(75,30,4);
//设置类型为数字和字母混合
captcha.setCharType(Captcha.TYPE_DEFAULT);
//设置字体
captcha.setCharType(Captcha.FONT_9);
//验证码存入session
httpServletRequest.getSession().setAttribute("verifyCode",captcha.text().toLowerCase());
//输出图片流
captcha.out(httpServletResponse.getOutputStream());
}
@GetMapping("/verify")
@ResponseBody
public String verify(@RequestParam("code") String code, HttpSession session){
if(StringUtils.isEmpty(code)){
return "验证码不能为空";
}
String kapchaCode = session.getAttribute("verifyCode")+"";
if(StringUtils.isEmpty(kapchaCode)||!code.toLowerCase().equals(kapchaCode)){
return "验证码输入错误";
}
return "验证成功";
}
}
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>验证码验证</title>
</head>
<body>
<img src="/kaptcha" onclick="this.src='/kaptcha?d=new Date()'">
<br>
<input type="text" maxlength="5" id="code" placeholder="请输入验证码"/>
<button id="verify">验证</button>
<br/>
<p id="verifyResult"></p>
</body>
<script src="https://s3.pstatp.com/cdn/expire-1-M/jquery/3.3.1/jquery.min.js"></script>
<script type="text/JavaScript" >
$(function(){
//验证按钮点击事件
$('#verify').click(function(){
var code=$('#code').val();
$.ajax({
type:'GET',//方法类型
url:'/verify?code='+code,
success:function(result){
$('#verifyResult').html(result);
},
error:function(){
alert('请求失败');
},
});
});
});
</script>
</html>
生成验证码功能还是比较常用的,所以记录整理一下,方便以后回顾,如果有帮到你们的地方倍感荣幸,有路过的大佬还望不吝雅教!