java生成二维码扫码网页自动登录功能
找了很多资料，七七八八都试了一遍，最终写出来了这个功能。
菜鸟一枚，此文只为做笔记。
简单的一个生成二维码，通过网页确认登录，实现二维码页面跳转到主页面。
有三个servlet：
CodeServlet.java 干2件事
a:生成随机的uuid,是一个唯一标识，该标识贯穿整个流程
b:生成二维码图片，二维码信息：http://xx.xx.xx.xx:8080/xxxx/login.jsp?uuid= xxxx
LongConnectionCheckServlet.java
进行长连接轮询操作，参数为uuid，查找loginMap中是否有此uuid，如果有则停止轮询，loginMap中remove这个uuid
PhoneLoginServlet.java 干2件事
a:检测登录，查看是否有此uuid
b:登录成功后将登录信息插入到loginMap中去，uuid为key
-------- Servlet 需要配置web.xml --------
UserLoginInfoVO.java
用户登录信息存储用户名密码（其他的还可以加，我只写了简单的）
LoginUser.java
用HashMap存用户登录信息
TwoDimensionCode.java
最关键的生成二维码的类，实现QRCodeImage，需要QRCode.jar包
QRCode.jar下载地址：http://vdisk.weibo.com/s/A25JOYrYFK9xO
UserLoginInfoVO.java
public class UserLoginInfoVO { private String userName; private String userPass; public String getUserName() { return userName; } public void setUserName(String userName) { this.userName = userName; } public String getUserPass() { return userPass; } public void setUserPass(String userPass) { this.userPass = userPass; } }
LoginUser.java
import java.util.HashMap;
public class LoginUser { private static HashMap<String, UserLoginInfoVO> loginMap = new HashMap<String, UserLoginInfoVO>(); private static UserLoginInfoVO userLoginInfoVO; public static UserLoginInfoVO getVO() { if (userLoginInfoVO == null) { userLoginInfoVO = new UserLoginInfoVO(); } return userLoginInfoVO; } public static HashMap<String, UserLoginInfoVO> getLoginMap() { return loginMap; } }
TwoDimensionCode.java
import java.awt.Color; import java.awt.Graphics2D; import java.awt.image.BufferedImage; import java.io.File; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import javax.imageio.ImageIO; import com.swetake.util.Qrcode; import jp.sourceforge.qrcode.QRCodeDecoder; import jp.sourceforge.qrcode.exception.DecodingFailedException; public class TwoDimensionCode { /** * 生成二维码(QRCode)图片 * * @param content * 存储内容 * @param imgPath * 图片路径 * @param imgType * 图片类型 * @param output * 输出流 * @param size * 二维码尺寸 */ public void encoderQRCode(String content, String imgPath) { this.encoderQRCode(content, imgPath, "png", 7); } public void encoderQRCode(String content, OutputStream output) { this.encoderQRCode(content, output, "png", 7); } public void encoderQRCode(String content, String imgPath, String imgType) { this.encoderQRCode(content, imgPath, imgType, 7); } public void encoderQRCode(String content, OutputStream output, String imgType) { this.encoderQRCode(content, output, imgType, 7); } public void encoderQRCode(String content, String imgPath, String imgType, int size) { try { BufferedImage bufImg = this.qRCodeCommon(content, imgType, size); File imgFile = new File(imgPath); if (!imgFile.exists()) { imgFile.mkdirs(); } // 生成二维码QRCode图片 ImageIO.write(bufImg, imgType, imgFile); } catch (Exception e) { e.printStackTrace(); } } public void encoderQRCode(String content, OutputStream output, String imgType, int size) { try { BufferedImage bufImg = this.qRCodeCommon(content, imgType, size); // 生成二维码QRCode图片 ImageIO.write(bufImg, imgType, output); } catch (Exception e) { e.printStackTrace(); } } /** * 生成二维码(QRCode)图片的公共方法 * * @return BufferedImage */ private BufferedImage qRCodeCommon(String content, String imgType, int size) { BufferedImage bufImg = null; try { Qrcode qrcode = new Qrcode(); // 设置二维码排错率，可选L(7%)、M(15%)、Q(25%)、H(30%)，排错率越高可存储的信息越少，但对二维码清晰度的要求越小 qrcode.setQrcodeErrorCorrect('M'); qrcode.setQrcodeEncodeMode('B'); // 设置设置二维码尺寸，取值范围1-40，值越大尺寸越大，可存储的信息越大 qrcode.setQrcodeVersion(size); // 获得内容的字节数组，设置编码格式 byte[] contentBytes = content.getBytes("utf-8"); // 图片尺寸 int imgSize = 67 + 12 * (size - 1); // BufferedImage.TYPE_INT_RGB表示一个图像，该图像具有整数像素的 8 位 RGB 颜色 bufImg = new BufferedImage(imgSize, imgSize, BufferedImage.TYPE_INT_RGB); Graphics2D gs = bufImg.createGraphics(); // 设置背景颜色 gs.setBackground(Color.WHITE); // 画矩形 gs.clearRect(0, 0, imgSize, imgSize); // 设定图像颜色 BLACK gs.setColor(Color.BLACK); // 设置偏移量，不设置可能导致解析出错 int pixoff = 2; // 输出内容> 二维码 if (contentBytes.length > 0 && contentBytes.length < 800) { // calQrcode()让字符串生成二维码。 boolean[][] codeOut = qrcode.calQrcode(contentBytes); for (int i = 0; i < codeOut.length; i++) { for (int j = 0; j < codeOut.length; j++) { if (codeOut[j][i]) { gs.fillRect(j * 3 + pixoff, i * 3 + pixoff, 3, 3); } } } } else { throw new Exception("QRCode content bytes length = " + contentBytes.length + " not in [0, 800]."); } gs.dispose(); bufImg.flush(); } catch (Exception e) { e.printStackTrace(); } return bufImg; }
}
CodeServlet.java
import java.io.IOException; import java.io.PrintWriter; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import com.dsjstudio.loanfront.useras.utils.TwoDimensionCode; public class CodeServlet extends HttpServlet { private static final long serialVersionUID = 1L; protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { PrintWriter out = response.getWriter(); // 生成唯一ID int uuid = (int) (Math.random() * 100000); // 二维码内容 String content = "http://localhost:8080/xxxx/index.jsp?uuid=" + uuid; // 生成二维码 String imgName = "image_" + uuid + ".png"; String imgPath = "D:/images/" + imgName; TwoDimensionCode handler = new TwoDimensionCode(); handler.encoderQRCode(content, imgPath, "png"); System.out.println(content); // 生成的图片访问地址 String qrCodeImg = "http://localhost:8080/images/" + imgName; String jsonStr = "{\"uuid\":" + uuid + ",\"qrCodeImg\":\"" + qrCodeImg + "\"}"; out.print(jsonStr); out.flush(); out.close(); } }
LongConnectionCheckServlet.java
import java.io.IOException; import java.io.PrintWriter; import java.util.Date; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import com.dsjstudio.loanfront.useras.controller.user.controller.LoginUser; import com.dsjstudio.loanfront.useras.controller.user.vo.UserLoginInfoVO; public class LongConnectionCheckServlet extends HttpServlet { private static final long serialVersionUID = 1L; protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String uuid = request.getParameter("uuid"); String jsonStr = ""; System.out.println("in"); System.out.println("uuid:" + uuid); long inTime = new Date().getTime(); Boolean bool = true; while (bool) { try { Thread.sleep(2000); } catch (InterruptedException e) { e.printStackTrace(); } // 检测登录 UserLoginInfoVO userVo = LoginUser.getLoginMap().get(uuid); System.out.println("userVo:" + userVo); if (userVo != null) { bool = false; jsonStr = "{\"uname\":\"" + userVo.getUserName() + "\"}"; LoginUser.getLoginMap().remove(uuid); } else { if (new Date().getTime() - inTime > 5000) { bool = false; } } } System.out.println("login ok : " + jsonStr); PrintWriter out = response.getWriter(); out.print(jsonStr); out.flush(); out.close(); } }
PhoneLoginServlet.java
import java.io.IOException; import java.io.PrintWriter; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import com.dsjstudio.loanfront.useras.controller.user.controller.LoginUser; import com.dsjstudio.loanfront.useras.controller.user.vo.UserLoginInfoVO; public class PhoneLoginServlet extends HttpServlet { private static final long serialVersionUID = 1L; protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String uuid = request.getParameter("uuid"); String uname = request.getParameter("uname"); String upwd = request.getParameter("upwd"); System.out.println(uuid); System.out.println(uname); System.out.println(upwd); // TODO 验证登录 boolean bool = true; if (bool) { // 将登陆信息存入map UserLoginInfoVO userVo = LoginUser.getLoginMap().get(uuid); if (userVo == null) { userVo = new UserLoginInfoVO(); userVo.setUserName(uname); userVo.setUserPass(upwd); LoginUser.getLoginMap().put(uuid, userVo); } } PrintWriter out = response.getWriter(); out.print(bool); out.flush(); out.close(); } }
两个jsp页面：
index.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <meta charset="UTF-8"> <title>Insert title here</title> <script type="text/javascript" src="https://code.jquery.com/jquery-3.3.1.min.js"></script> <script type="text/javascript"> $(document).ready(function() { var uuid; //alert("1"); $.get("/dsjstudio-loan-user-as/CodeServlet", function(data, status) { var obj = eval("(" + data + ")"); //alert("2"); //存储UUID uuid = obj.uuid; //显示二维码 $("#QrCodeImg").attr("src", obj.qrCodeImg); // alert(obj.qrCodeImg); //开始验证登录 validateLogin(); }); function validateLogin(){ $.get("/dsjstudio-loan-user-as/LongConnectionCheckServlet?uuid=" + uuid , function(data, status) { if(data == ""){ validateLogin(); }else{ var obj = eval("(" + data + ")"); alert("欢迎您回家:" + obj.uname); window.location.href='http://www.baidu.com'; } }); } }); </script> </head> <body> <h1>哥么敢不敢扫一下！</h1> <div id="divCon"> <img src="" id="QrCodeImg" /> </div> </body> </html>
login.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>点确认吧小伙子</title> <script type="text/javascript" src="https://code.jquery.com/jquery-3.3.1.min.js"></script> <script type="text/javascript"> //登录 function login() $.post("/dsjstudio-loan-user-as/PhoneLoginServlet", { uuid : $.getUrlParam('uuid'), uname:$("#login_name").val(), upwd:$("#login_psw").val() }, function(data, status) { if(data == ""){ alert("登录失败"); }else{ alert("登录成功"); } }); } //获取网页参数 (function($){ $.getUrlParam = function(name){ //这个正则是寻找&+url参数名字=值+& var reg = new RegExp("(^|&)"+ name +"=([^&]*)(&|$)"); //这里是开始匹配，找到了返回对应url值，没找到返回null。 var r = window.location.search.substr(1).match(reg); if (r!=null) return unescape(r[2]); return null; } })(jQuery); </script> </head> <body> <div> <p> <span>名称：</span> <input type="text" id="login_name" value="lingzi"> </p> <p> <span>密码：</span> <input type="password" id="login_psw" value="xxxxxxxxx"> </p> <div> <a href="javascript:login()">登录</a> </div> </div> </body> </html>
因为连的是本地的tomcat，所以是直接电脑上操作，二维码出来，有一个uuid打印在Console上，复制粘贴到网址上
实现效果图：
Console上uuid打印出来62951
点击登录
返回index.jsp页面查看，成功~点击确认跳转页面啦~
web.xml配置
<servlet> <description></description> <display-name>长连接检查登录状态</display-name> <servlet-name>LongConnectionCheckServlet</servlet-name> <servlet-class>com.dsjstudio.loanfront.useras.controller.user.servlet.LongConnectionCheckServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>LongConnectionCheckServlet</servlet-name> <url-pattern>/LongConnectionCheckServlet</url-pattern> </servlet-mapping> <servlet> <description>获取二维码图片以及uuid</description> <display-name>CodeServlet</display-name> <servlet-name>CodeServlet</servlet-name> <servlet-class>com.dsjstudio.loanfront.useras.controller.user.servlet.CodeServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>CodeServlet</servlet-name> <url-pattern>/CodeServlet</url-pattern> </servlet-mapping> <servlet> <description>手机扫描二维码之后进行登录</description> <display-name>PhoneLoginServlet</display-name> <servlet-name>PhoneLoginServlet</servlet-name> <servlet-class>com.dsjstudio.loanfront.useras.controller.user.servlet.PhoneLoginServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>PhoneLoginServlet</servlet-name> <url-pattern>/PhoneLoginServlet</url-pattern> </servlet-mapping>
