java生成带参数的小程序二维码扫描后在小程序端获取参数

一、Java端

1、搭建一个springboot项目,引入以下pom依赖

<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <!-- https://mvnrepository.com/artifact/top.jfunc.common/converter -->
        <dependency>
            <groupId>top.jfunc.common</groupId>
            <artifactId>converter</artifactId>
            <version>1.8.0</version>
        </dependency>

        <dependency>
            <groupId>net.sf.json-lib</groupId>
            <artifactId>json-lib</artifactId>
            <version>2.4</version>
            <classifier>jdk15</classifier>
        </dependency>


        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.7.4</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.7.4</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>2.7.4</version>
        </dependency>
    </dependencies>

2、新建2个工具类 UrlUtil、CreateQrcore

1、UrlUtil //向指定 URL 发送POST方法的请求

package com.example.utils;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.URL;
import java.net.URLConnection;
import java.util.Iterator;
import java.util.Map;

public class UrlUtil {
    /**
     * 向指定 URL 发送POST方法的请求
     *
     * @param url 发送请求的 URL
     * @return 所代表远程资源的响应结果
     */
    public static String sendPost(String url, Map<String, ?> paramMap) {
        PrintWriter out = null;
        BufferedReader in = null;
        String result = "";

        String param = "";
        Iterator<String> it = paramMap.keySet().iterator();

        while(it.hasNext()) {
            String key = it.next();
            param += key + "=" + paramMap.get(key) + "&";
        }

        try {
            URL realUrl = new URL(url);
            // 打开和URL之间的连接
            URLConnection conn = realUrl.openConnection();
            // 设置通用的请求属性
            conn.setRequestProperty("accept", "*/*");
            conn.setRequestProperty("connection", "Keep-Alive");
            conn.setRequestProperty("Accept-Charset", "utf-8");
            conn.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            // 发送POST请求必须设置如下两行
            conn.setDoOutput(true);
            conn.setDoInput(true);
            // 获取URLConnection对象对应的输出流
            out = new PrintWriter(conn.getOutputStream());
            // 发送请求参数
            out.print(param);
            // flush输出流的缓冲
            out.flush();
            // 定义BufferedReader输入流来读取URL的响应
            in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            System.out.println(e);
        }
        //使用finally块来关闭输出流、输入流
        finally{
            try{
                if(out!=null){
                    out.close();
                }
                if(in!=null){
                    in.close();
                }
            }
            catch(Exception ex){
                ex.printStackTrace();
            }
        }
        return result;
    }
}

2、CreateQrcore 创建二维码设定二维码的参数、生成后保存的地址等等

paramJson.put("scene","2");//这一句就是你二维码里携带的参数 String型名称不可变

package com.example.utils;


import net.sf.json.JSONObject;

import javax.servlet.http.HttpServletRequest;
import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.LinkedHashMap;
import java.util.Map;

public class CreateQrcore {

    /*
     * 获取 token
　　　* 普通的 get 可获 token
     */
    public  static String getToken() {
        try {
            Map<String, String> map = new LinkedHashMap<>();
            map.put("grant_type", "client_credential");
            map.put("appid","xxxxxxxxxxxxxx");
            map.put("secret", "xxxxxxxxxxxxxxxxxxxxx");

            String rt = UrlUtil.sendPost("https://api.weixin.qq.com/cgi-bin/token", map);
            System.out.println("what is:"+rt);
            JSONObject json = JSONObject.fromObject(rt);

            if (json.getString("access_token") != null || json.getString("access_token") != "") {
                return json.getString("access_token");
            } else {
                return null;
            }
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /*
     * 获取 二维码图片
　　 *
     */
    public static String getminiqrQr( String accessToken,HttpServletRequest request) {
        String p="F://code"; //二维码生产的地址  本地F盘code文件夹
        System.out.println(p);
        String codeUrl=p+"/twoCode.png";
        String twoCodeUrl="twoCode.png";
        try
        {
            URL url = new URL("https://api.weixin.qq.com/wxa/getwxacodeunlimit?access_token="+accessToken);
            HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
            httpURLConnection.setRequestMethod("POST");// 提交模式
            // conn.setConnectTimeout(10000);//连接超时 单位毫秒
            // conn.setReadTimeout(2000);//读取超时 单位毫秒
            // 发送POST请求必须设置如下两行
            httpURLConnection.setDoOutput(true);
            httpURLConnection.setDoInput(true);
            // 获取URLConnection对象对应的输出流
            PrintWriter printWriter = new PrintWriter(httpURLConnection.getOutputStream());
            // 发送请求参数
            JSONObject paramJson = new JSONObject();
            paramJson.put("scene","2");//这就是你二维码里携带的参数 String型  名称不可变
            paramJson.put("path", "pages/index/index"); //这是设置扫描二维码后跳转的页面
            paramJson.put("width", 430);
            paramJson.put("is_hyaline", true);
            paramJson.put("auto_color", true);

            System.out.println("httpURLConnection"+httpURLConnection);
            System.out.println("paramJson.toString()"+paramJson.toString());
            printWriter.write(paramJson.toString());
            // flush输出流的缓冲
            printWriter.flush();
            //开始获取数据
            BufferedInputStream bis = new BufferedInputStream(httpURLConnection.getInputStream());
            OutputStream os = new FileOutputStream(new File(codeUrl));
            int len;
            byte[] arr = new byte[1024];
            while ((len = bis.read(arr)) != -1)
            {
                os.write(arr, 0, len);
                os.flush();
            }
            os.close();
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
        return twoCodeUrl;
    }
}

3、创建一个Controller作接口调用

package com.example.controller;

import com.example.utils.CreateQrcore;
import net.sf.json.JSONObject;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;

import javax.servlet.http.HttpServletRequest;
import java.io.IOException;

@RestController
public class CoreController {


    /**
     * 接收二维码
     * @param request
     * @return
     * @throws IOException
     */
    @RequestMapping(value="/twoCode",method= RequestMethod.POST,produces="text/html;charset=utf-8")
    @ResponseBody
    public Object twoCode( HttpServletRequest request) throws IOException{

        JSONObject data=new JSONObject();
        String accessToken = CreateQrcore.getToken();
        System.out.println("accessToken;"+accessToken);
        String twoCodeUrl = CreateQrcore.getminiqrQr(accessToken,request);
        data.put("twoCodeUrl", twoCodeUrl);
        return data;
    }
}

二、小程序端

1、在二维码设置的跳转页面里的JS中写入以下代码进行获取二维码的参数

在onLoad()方法中加上options参数，然后用decodeURIComponent转一次码后进行或许，这些操作都是必须的，而且scene这个变量名是不可变的

onLoad(options) {
            var scene_id = decodeURIComponent(options.scene); //获取二维码的参数
            console.info('scene_id : ' +scene_id)
            
            if(scene_id == 'undefined' || !scene_id || scene_id == null ){
                wx.reLaunch({
                    url: '/pages/index/share',
                })
                return false;
            }
            
            this.scene = scene_id;   //获取的机器码编号
            console.info(this.scene)
            //检查登录是否过期
            wx.checkSession({
                success: function(e) { //登录态未过期
                    console.log(new Date() + "未过期");
                },
                fail: function() { //登录态过期了
                    console.log(new Date() + "已过期");
                }
            });
        },

2、拿刚刚生成的二维码在小程序端进行测试，在微信开发者工具里有个通过二维码编译，点击后选择刚刚生成的二维码

image.png

3、获取参数成功~~

image.png

java生成带参数的小程序二维码 扫描后在小程序端获取参数

java生成带参数的小程序二维码扫描后在小程序端获取参数