二维码扫码登录

不念不忘少年蓝@ 2021-09-27 02:46 548阅读 0赞

**   项目结构**

![70][]

**模块介绍**

**![70 1][]**

**流程1**

pc端：  
  
1:打开二维码登录网页index.html  
2:index.html调用GetQrCodeServlet  
3:GetQrCodeServlet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://60.28.201.37:8380/QrCodeLoginPro/Login.html?uuid=" + uuid  
4:index页面展示二维码  
5:index页面调用LongConnectionCheckServlet进行长连接轮询操作，参数为uuid  
6:LongConnectionCheckServlet只干1件事  
   a:拿到uuid后循环检查loginUserMap中uuid是否不为null。  
7:如果为null则代表没有登录，index.html将继续进行轮询  
  
ps:  
LongConnectionCheckServlet  一个长连接请求检测登录状态

loginUserMap 是一个静态的map结构的登录池，uuid为key , 登录信息为value

**流程2**

手机端：  
  
  
1:扫描pc端的二维码  
2:打开二维码中的网页 http://60.28.201.37:8380/QrCodeLoginPro/Login.html?uuid=" + uuid  
3:登录，将uname upwd uuid 传递给登录程序PhoneLoginServlet  
4:PhoneLoginServlet干2件事  
   a:检测登录  
   b:登录成功后将登录信息插入到loginUserMap中去，uuid为key  
  
pc端：  
1:继续轮询检测uuid中是否为null,

2:登录后的uuid中就不为null了，此时LongConnectionCheckServlet停止循环，返回登录状态。

LongConnectionCheckServlet.java

package cn;
    
    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 cn.vo.LoginUserVo;
    import cn.vo.UserVo;
    
    /**
     * 用长连接，检查登录状态
     *
     */
    public class LongConnectionCheckServlet extends HttpServlet {
    	private static final long serialVersionUID = 1L;
        public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    		doPost(request, response);
    	}
        public 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(1000);
    			} catch (InterruptedException e) {
    				e.printStackTrace();
    			}
    			//检测登录
    			UserVo userVo = LoginUserVo.getLoginUserMap().get(uuid);
    			System.out.println("userVo:" + userVo);
    			if(userVo != null){
    				bool = false;
    				jsonStr = "{\"uname\":\""+userVo.getUname()+"\"}";
    				LoginUserVo.getLoginUserMap().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();
    	}
    }

GetQrCodeServlet.java

package cn;
    
    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 cn.util.TwoDimensionCode;
    
    /**
     * 生成二维码图片以及uuid
     *
     */
    public class GetQrCodeServlet 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://127.0.0.1:8080/QrCodeLoginPro/Login.html?uuid=" + uuid;
    		//生成二维码
    		String imgName =  uuid + "_" + (int) (new Date().getTime() / 1000) + ".png";
    		String imgPath = "F://apache-tomcat-7/webapps/QrCodeLoginPro/" + imgName;
    		TwoDimensionCode handler = new TwoDimensionCode();
    		handler.encoderQRCode(content, imgPath, "png");
    		
    		//生成的图片访问地址
    		String qrCodeImg = "http://127.0.0.1:8080/QrCodeLoginPro/" + imgName;
    		String jsonStr = "{\"uuid\":" + uuid + ",\"qrCodeImg\":\"" + qrCodeImg + "\"}";
    		out.print(jsonStr);
    		out.flush();
    		out.close();
    	}
    }

PhoneLoginServlet.java

package cn;
    
    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 cn.vo.LoginUserVo;
    import cn.vo.UserVo;
    
    /**
     * 二维码手机端登录
     *
     */
    public class PhoneLoginServlet extends HttpServlet {
    	private static final long serialVersionUID = 1L;
        public PhoneLoginServlet() {
            super();
            // TODO Auto-generated constructor stub
        }
    	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);
    		//验证登录
    		boolean bool = true;
    		if(bool){
    			//将登陆信息存入map
    			UserVo userVo = LoginUserVo.getLoginUserMap().get(uuid);
    			if(userVo == null){
    				userVo = new UserVo();
    				userVo.setUname(uname);
    				userVo.setUpwd(upwd);
    				LoginUserVo.getLoginUserMap().put(uuid, userVo);
    			}
    		}
    		PrintWriter out = response.getWriter();
    		out.print(bool);
    		out.flush();
    		out.close();
    	}
    }

**项目下载地址：https://pan.baidu.com/s/1dwSBbqqdNPFk6LMzmpJY2A**

**                                                               本文转载地址：https://blog.csdn.net/lwjdear/article/details/78427791**

[70]: /images/20210923/0aa2f0166f6943dda9fea4865f063a99.png
[70 1]: /images/20210923/e4bf13fe788e4e22940712cd1d321f13.png