这边演示下idea+maven+servlet实现谷歌的kaptcha验证码的使用:
web.xml, 这边主要是kaptcha验证器，
<!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd" > <web-app> <display-name>Archetype Created Web Application</display-name> <servlet> <servlet-name>validcode</servlet-name> <servlet-class>ValidCode</servlet-class> </servlet> <servlet-mapping> <servlet-name>validcode</servlet-name> <url-pattern>/validcode</url-pattern> </servlet-mapping> <servlet> <servlet-name>kaptcha</servlet-name> <servlet-class>com.google.code.kaptcha.servlet.KaptchaServlet</servlet-class> <init-param> <param-name>kaptcha.border</param-name> <param-value>no</param-value> </init-param> <init-param> <param-name>kaptcha.border.color</param-name> <param-value>105,179,90</param-value> </init-param> <init-param> <param-name>kaptcha.textproducer.font.color</param-name> <param-value>red</param-value> </init-param> <init-param> <param-name>kaptcha.image.width</param-name> <param-value>100</param-value> </init-param> <init-param> <param-name>kaptcha.image.height</param-name> <param-value>45</param-value> </init-param> <init-param> <param-name>kaptcha.textproducer.font.size</param-name> <param-value>35</param-value> </init-param> <!-- 配置session的存储的KEY --> <init-param> <param-name>kaptcha.session.key</param-name> <param-value>session_code</param-value> </init-param> <init-param> <param-name>kaptcha.textproducer.char.length</param-name> <param-value>4</param-value> </init-param> <init-param> <param-name>kaptcha.textproducer.font.names</param-name> <param-value>宋体,楷体,微软雅黑</param-value> </init-param> </servlet> <servlet-mapping> <servlet-name>kaptcha</servlet-name> <url-pattern>/code</url-pattern> </servlet-mapping> </web-app>
然后是maven依赖，引入kaptcha， 阿里的快速json，以及apache的io流，
因为kaptcha依赖我这边下不下来所以就下载下来放在lib里面再导入，如图:
maven依赖如下:
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.linewell</groupId> <artifactId>Kaptcha</artifactId> <version>1.0-SNAPSHOT</version> <packaging>war</packaging> <name>Kaptcha Maven Webapp</name> <!-- FIXME change it to the project's website --> <url>http://www.example.com</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <maven.compiler.source>1.7</maven.compiler.source> <maven.compiler.target>1.7</maven.compiler.target> </properties> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.11</version> <scope>test</scope> </dependency> <dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> <version>3.1.0</version> </dependency> <dependency> <groupId>com.google.code</groupId> <artifactId>kaptcha</artifactId> <version>2.3.2</version> <scope>system</scope> <systemPath>${project.basedir}/src/main/webapp/WEB-INF/lib/kaptcha-2.3.2.jar</systemPath> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>1.2.54</version> </dependency> <dependency> <groupId>commons-io</groupId> <artifactId>commons-io</artifactId> <version>2.6</version> </dependency> </dependencies> <build> <finalName>Kaptcha</finalName> <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) --> <plugins> <plugin> <artifactId>maven-clean-plugin</artifactId> <version>3.1.0</version> </plugin> <!-- see http://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_war_packaging --> <plugin> <artifactId>maven-resources-plugin</artifactId> <version>3.0.2</version> </plugin> <plugin> <artifactId>maven-compiler-plugin</artifactId> <version>3.8.0</version> </plugin> <plugin> <artifactId>maven-surefire-plugin</artifactId> <version>2.22.1</version> </plugin> <plugin> <artifactId>maven-war-plugin</artifactId> <version>3.2.2</version> </plugin> <plugin> <artifactId>maven-install-plugin</artifactId> <version>2.5.2</version> </plugin> <plugin> <artifactId>maven-deploy-plugin</artifactId> <version>2.8.2</version> </plugin> </plugins> </pluginManagement> </build> </project>
前端的jsp代码如下:
<html> <head> <meta charset="utf-8"> <link rel="stylesheet" href="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/css/bootstrap.min.css"> <script src="https://cdn.staticfile.org/jquery/1.10.2/jquery.min.js"></script> <script src="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/js/bootstrap.min.js"></script> </head> <body> <div style=" 100%; margin-top: 30px;" align="center" > <div class="form-inline"> <input type="text" id="text" class="form-control" style=" 150px"/> <img id="img" src="/code" alt="picture dismiss" /> </div> <div class="form-inline" style="margin-top: 15px;"><input type="button" id="sub" value="submit" class="btn-primary" style=" 100px;"/></div> </div> <script> $(function () { $("#img").bind("click", function () { $("#img").attr("src", "/code?"+new Date().getTime()); console.log($('#img').attr("src")); }); $("#sub").click(function () { var input = $("#text").val(); console.log(input); var data = {}; data.code = input; $.ajax({ type:"post", dataType: "json", url : "/validcode", contentType:"application/json; charset=utf-8", data: JSON.stringify(data), success: function (t) { alert(t.msg); }, failure: function (data) { console.log(data); } }); }); }); </script> </body> </html>
后台测试的servlet如下:
import com.alibaba.fastjson.JSONObject; import org.apache.commons.io.IOUtils; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.io.InputStream; import java.io.PrintWriter; public class ValidCode extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException { InputStream inputStream = request.getInputStream(); String bodyInfo = IOUtils.toString(inputStream, "utf-8"); System.out.println(bodyInfo); JSONObject jsonObject = JSONObject.parseObject(bodyInfo); String code = jsonObject.getString("code"); String attribute = (String) request.getSession().getAttribute("session_code"); Data data = new Data(); if(code.equals(attribute)){ System.out.println("验证码正确!"); data.setMsg("success"); }else { System.out.println("验证码输入错误"); data.setMsg("fail"); } response.setCharacterEncoding("UTF-8"); response.setContentType("application/json; charset=utf-8"); String jsonString = JSONObject.toJSONString(data); PrintWriter writer = response.getWriter(); writer.write(jsonString); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } } class Data{ private String msg; public String getMsg() { return msg; } public void setMsg(String msg) { this.msg = msg; } }
最后的效果展示:
