微信wxacode.getUnlimited接口生成小程序码

官方文档链接：https://developers.weixin.qq.com/miniprogram/dev/api-backend/open-api/qr-code/wxacode.getUnlimited.html

我是基于若依框架写的，复制的这个人的代码，在他的基础上改了改https://blog.csdn.net/m0_58440053/article/details/122230926?utm_medium=distribute.pc_relevant.none-task-blog-2~default~baidujs_title~default-1.queryctrv2&spm=1001.2101.3001.4242.2&utm_relevant_index=4

access_token缓存是按照这个人的思路写的模拟的缓存https://www.cnblogs.com/setukirin/p/5718059.html

注意：access_token是后台向下面这个地址发送get请求，返回的值，不是登陆系统后生成的token

https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=APPID&secret=APPSECRET

这个地址里的appid和secret的获取方式在最下面，grant_type的值就写client_credential就行了

maven导包

        <!--httpclient,用来发送https请求-->
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
        </dependency>

实体类

 1 public class WeiXinAccessTokenDTO {
 2     private String grant_type;
 3     private String appid;
 4     private String secret;
 5 
 6     public String getGrant_type() {
 7         return grant_type;
 8     }
 9 
10     public void setGrant_type(String grant_type) {
11         this.grant_type = grant_type;
12     }
13 
14     public String getAppid() {
15         return appid;
16     }
17 
18     public void setAppid(String appid) {
19         this.appid = appid;
20     }
21 
22     public String getSecret() {
23         return secret;
24     }
25 
26     public void setSecret(String secret) {
27         this.secret = secret;
28     }
29 
30     @Override
31     public String toString() {
32         return "WeiXinAccessTokenDTO{" +
33                 "grant_type='" + grant_type + '\'' +
34                 ", appid='" + appid + '\'' +
35                 ", secret='" + secret + '\'' +
36                 '}';
37     }
38 }

import java.util.Map;

public class WeiXinUnlimitedDTO {
    private String access_token;
    //访问接口需要的选填的参数，直接map键值对转换json
    private Map<String, Object> params;

    public String getAccess_token() {
        return access_token;
    }

    public void setAccess_token(String access_token) {
        this.access_token = access_token;
    }

    public Map<String, Object> getParams() {
        return params;
    }

    public void setParams(Map<String, Object> params) {
        this.params = params;
    }

    @Override
    public String toString() {
        return "WeiXinUnlimitedDTO{" +
                "access_token='" + access_token + '\'' +
                ", params=" + params +
                '}';
    }
}

getAccessToken.properties

appid = xxxxxxx//只有注册成为开发者才能得到appid,下面有获取方式
secret = xxxxxxxxxxxxxxxxx//和appid一样
grant_type = client_credential

service层

  1 import com.alibaba.fastjson.JSONObject;
  2 import com.ruoyi.common.core.domain.AjaxResult;
  3 import com.ruoyi.common.utils.http.HttpUtils;
  4 import com.ruoyi.manager.domain.dto.WeiXinAccessTokenDTO;
  5 import org.apache.http.HttpEntity;
  6 import org.apache.http.HttpResponse;
  7 import org.apache.http.HttpStatus;
  8 import org.apache.http.client.methods.HttpPost;
  9 import org.apache.http.entity.StringEntity;
 10 import org.apache.http.impl.client.CloseableHttpClient;
 11 import org.apache.http.impl.client.HttpClients;
 12 import org.springframework.stereotype.Service;
 13 
 14 import javax.servlet.http.HttpServletResponse;
 15 import java.io.*;
 16 import java.nio.charset.Charset;
 17 import java.util.Date;
 18 import java.util.HashMap;
 19 import java.util.Map;
 20 import java.util.Properties;
 21 
 22 @Service
 23 public class QRCodeService {
 24     //用来存放access_token
 25     private Map<String,Object> token=new HashMap<>();
 26 
 27     /**
 28      * 发送http请求访问微信小程序接口获得输入流
 29      * @param URL
 30      * @param json
 31      * @return
 32      */
 33     public static ByteArrayInputStream sendPost(String URL, String json) {
 34         InputStream inputStream = null;
 35         ByteArrayInputStream byteArrayInputStream = null;
 36         // 创建默认的httpClient实例.
 37         CloseableHttpClient httpclient = HttpClients.createDefault();
 38         // 创建httppost
 39         HttpPost httppost = new HttpPost(URL);
 40         httppost.addHeader("Content-type", "application/json; charset=utf-8");
 41         httppost.setHeader("Accept", "application/json");
 42         try {
 43             StringEntity s = new StringEntity(json, Charset.forName("UTF-8"));
 44             s.setContentEncoding("UTF-8");
 45             httppost.setEntity(s);
 46             HttpResponse response = httpclient.execute(httppost);
 47             if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
 48                 // 获取相应实体
 49                 HttpEntity entity = response.getEntity();
 50                 inputStream = entity.getContent();
 51                 ByteArrayOutputStream outStream = new ByteArrayOutputStream();
 52                 // 创建一个Buffer字符串
 53                 byte[] buffer = new byte[1024];
 54                 // 每次读取的字符串长度，如果为-1，代表全部读取完毕
 55                 int len = 0;
 56                 // 使用一个输入流从buffer里把数据读取出来
 57                 while ((len = inputStream.read(buffer)) != -1) {
 58                     // 用输出流往buffer里写入数据，中间参数代表从哪个位置开始读，len代表读取的长度
 59                     outStream.write(buffer, 0, len);
 60                 }
 61                 // 关闭输入流
 62                 inputStream.close();
 63                 // 把outStream里的数据写入内存
 64                 byteArrayInputStream = new ByteArrayInputStream(outStream.toByteArray());
 65             }
 66         } catch (Exception e) {
 67             e.printStackTrace();
 68         } finally {
 69             // 关闭连接,释放资源
 70             try {
 71                 httpclient.close();
 72             } catch (IOException e) {
 73                 e.printStackTrace();
 74             }
 75         }
 76         return byteArrayInputStream;
 77     }
 78 
 79     /**
 80      * 返回菊花二维码图片给前端
 81      * @param access_token
 82      * @param paramJson
 83      * @param response
 84      * @return
 85      */
 86     public AjaxResult getWXCode(String access_token, String paramJson, HttpServletResponse response) {
 87         Map<String, Object> map = new HashMap<>();
 88         AjaxResult ajaxResult=null;
 89         try {
 90 //            log.info("access_token：[{}]", access_token);
 91             String url = "https://api.weixin.qq.com/wxa/getwxacodeunlimit?access_token=" + access_token;
 92             ByteArrayInputStream inputStream = sendPost(url, paramJson);
 93             //这里判断的是返回的图片还是错误信息，一般错误信息不会大于200
 94             if (inputStream.available() <= 200) {
 95                 ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
 96                 int i;
 97                 byte[] buffer = new byte[200];
 98                 while ((i = inputStream.read(buffer)) != -1) {
 99                     byteArrayOutputStream.write(buffer, 0, i);
100                 }
101                 String str = new String(byteArrayOutputStream.toByteArray());
102                 //错误信息的格式在官方文档里有
103                 JSONObject jsonObject = JSONObject.parseObject(str);
104 
113                 byteArrayOutputStream.close();
114                 return AjaxResult.error(Integer.parseInt(jsonObject.getString("errcode")),jsonObject.getString("errmsg"));
115             }
116             //返回web前端，这里返回的是base64
117             byte[] buff = new byte[inputStream.available()+1];
118             inputStream.read(buff,0,inputStream.available());
119             inputStream.close();
120             //下载到本地的代码
121 //            FileOutputStream fileOutputStream = new FileOutputStream("D:/123.png");
122 //            int i;
123 //            byte[] buffer = new byte[200];
124 //            while ((i = inputStream.read(buffer)) != -1) {
125 //                fileOutputStream.write(buffer, 0, i);
126 //            }
127 //            fileOutputStream.flush();
128 //            fileOutputStream.close();
129 //            inputStream.close();
130 //            map.put("true",buff);
131             ajaxResult=new AjaxResult(200,"获取小程序码成功",buff);
132         } catch (Exception e) {
133 
134             ajaxResult=new AjaxResult(500,"获取小程序码失败",null);
135         }
136         return ajaxResult;
137     }
138     //获取access_token
139     public Map<String, Object> getWeiXinAccessToken() {
140         WeiXinAccessTokenDTO dto = new WeiXinAccessTokenDTO();
141         Properties properties = new Properties();
142         File file=new File("项目名/src/main/resources/getAccessToken.properties");
143         FileReader reader=null;
144         try {
145             reader=new FileReader(file);
146             properties.load(reader);
147         } catch (FileNotFoundException e) {
148             e.printStackTrace();
149         } catch (IOException e) {
150             e.printStackTrace();
151         }
152
153         String appid=properties.getProperty("appid");
154         String secret=properties.getProperty("secret");
155         String grant_type=properties.getProperty("grant_type");
159         String param = "grant_type=" + grant_type + "&appid=" + appid + "&secret=" +secret;
160         String resultStr = HttpUtils.sendGet("https://api.weixin.qq.com/cgi-bin/token", param);
161
162         String[] strings = resultStr.split(",");
163         String[] access_token = strings[0].split("\"");
164         //把access_token放到模拟的缓存里
165         token.put("access_token", access_token[3]);
166         token.put("time",System.currentTimeMillis());
167 
168         return token;
169     }
170 
171     //得到缓存中的access_token，如果access_token过期则重新获取
172     public String getCacheAccessToken(){
173         Long time = (Long)token.get("time");
174         String access_token= (String) token.get("access_token");
175         Long nowDate = new Date().getTime();
176         if (access_token != null && time != null && nowDate - time < 7200 * 1000){
177             return access_token;
178         }else {
179             return (String) this.getWeiXinAccessToken().get("access_token");
180         }
181     }
182 
183 }

controller层

 1 import com.alibaba.fastjson.JSON;
 2 import com.ruoyi.common.core.domain.AjaxResult;
 3 import com.ruoyi.common.core.redis.RedisCache;
 4 import com.ruoyi.manager.service.QRCodeService;
 5 import org.springframework.beans.factory.annotation.Autowired;
 6 import org.springframework.web.bind.annotation.PostMapping;
 7 import org.springframework.web.bind.annotation.RequestBody;
 8 import org.springframework.web.bind.annotation.RequestMapping;
 9 import org.springframework.web.bind.annotation.RestController;
10 
11 import javax.servlet.http.HttpServletResponse;
12 import java.util.Map;
13 
14 @RestController
15 @RequestMapping("/manager/QRCode")
16 public class QRCodeController {
17     @Autowired
18     private QRCodeService service;
19 
20     @Autowired
21     private RedisCache redisCache;
22 
23 
24     @PostMapping("/getUnlimited")
25     public AjaxResult getWeiXinUnlimited(@RequestBody Map<String, Object> params, HttpServletResponse response) {
26 27 
28         String cacheAccessToken = service.getCacheAccessToken();
29         System.out.println("access_token1:  (" + cacheAccessToken + ")");
30         String s = JSON.toJSONString(params);
31         AjaxResult result = service.getWXCode(cacheAccessToken, s, response);
32         return result;
33     }
34 
35 }

前端vue代码

<template>
  <el-row>
    <el-col :span="24">
      <el-button icon="el-icon-search" size="mini" @click="getCode">获取小程序码</el-button>
      <img ref="img" :src="base64">
    </el-col>
  </el-row>
</template>

<script>
import { getAccessToken,getCode } from '@/api/manager/QRCode'
import request from '@/utils/request'

export default {
  name: 'QRCode',
  data(){
    return{
      accessToken:'',
      codeData:{
        access_token:'',
        params:{
          scene:"id=3",
        }
      },
      base64:'',
      imgUrl:'',
    }
  },
  methods:{
    getCode(){
      getCode(this.codeData.params).then(request=>{
        this.base64="data:image/jpg;base64,"+request.data;
      })
    },
  }
}
</script>

<style scoped>

</style>

QRCode.js

import request from '@/utils/request'
// 获取小程序码
export function getCode(data) {
  return request({
    url: '/manager/QRCode/getUnlimited',
    method: 'post',
    data: data
  })
}

获取appid和secret的步骤

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