微信小程序订阅消息开发指南(java)

第一步准备阶段

1、你得有一个小程序，并且认证了，个人的也行

2、开通订阅消息

小程序后台->功能->订阅消息

3、公共模板库选择一个模板

选择的时候，选择你需要的字段，因为字段有限制

4、我的模板点击详情

详情内容，模板 id 都是需要提供个服务端开发人员的

第二步编码阶段

小程序端

小程序消息订阅，需要用户确认

1、首先小程序授权登陆获取 code

官网示例：https://developers.weixin.qq.com/miniprogram/dev/api/open-api/login/wx.login.html

wx.login({
  success (res) {
    if (res.code) {
      //发起网络请求
      wx.request({
        url: 'https://example.com/onLogin',
        data: {
          code: res.code
        }
      })
    } else {
      console.log('登录失败！' + res.errMsg)
    }
  }
})
// 结果 {errMsg: "login:ok", code: "0a3kK4Ga10Gk3F0oBAHa1mGyRl3kK4Gd"}

uni-App 示例：https://uniapp.dcloud.net.cn/api/plugins/login.html#login

uni.login({
    provider: 'weixin', //使用微信登录
    success: function (loginRes) {
        console.log(loginRes)
    }
});
// 结果 {errMsg: "login:ok", code: "0a3kK4Ga10Gk3F0oBAHa1mGyRl3kK4Gd"}

2、将 code 传给服务端获取用户唯一标识 openId

3、通过代码起小程序消息订阅界面、用户点击确定ok，小程序工作结束

官方示例：https://developers.weixin.qq.com/miniprogram/dev/api/open-api/subscribe-message/wx.requestSubscribeMessage.html

tmplIds 填写模板 id 即可，最多三个

wx.requestSubscribeMessage({
  tmplIds: [''],
  success (res) {
      console.log(res)
  }
})

4、注意事项：

避免重复拉起用户订阅通知，可以通过微信提供的 getSetting 判断用户是否订阅了，如果没有就拉起。

注意下面是用uniapp写的，方法前缀是uni 如果你小程序代码记得修改 wx 以及提示组件

到此小程序工作结束

getSetting() {
    uni.getSetting({
        withSubscriptions: true, // 获取用户订阅状态
        success(res) {
            // false 表示用户未订阅改消息
            if (!res.subscriptionsSetting.mainSwitch) {
                this.subscribeMessage();
            } else {
                uni.showToast({
                    title: '已订阅',
                    icon: 'none'
                })
            }
        }
    })
},
subscribeMessage() {
    uni.requestSubscribeMessage({
        tmplIds: ['模板id'],
        success(res) {
            if (res.errMsg === 'requestSubscribeMessage:ok') {
                uni.showToast({
                    title: '订阅成功',
                    icon: 'none'
                })
            }
        }
    })
}

服务端

微信小程序的 appid 和 secret 小程序后台->开发->开发管理->开发设置->开发者 ID

注意事项：

http 请求这里使用 apache 的工具类，你也可以使用别的
微信消息模板字段 thing 字段有长度限制20，超过会失败
以下演示代码，生产环境还需进行优化

1、通过 code 获取用户 open id 官网文档

 public String getOpenId(String code) throws IOException {
        CloseableHttpClient httpClient = HttpClientBuilder.create().build();
        Map<String, Object> params = new HashMap<>();
        params.put("appid", Constants.APPLET_APP_ID);
        params.put("secret", Constants.APPLET_SECRET);
        params.put("js_code", code);
        params.put("grant_type", "authorization_code");

        String url = handleParams("https://api.weixin.qq.com/sns/jscode2session", params);
        HttpGet httpGet = new HttpGet(url);

        CloseableHttpResponse response = httpClient.execute(httpGet);
        HttpEntity entity = response.getEntity(); // 响应结果
        return EntityUtils.toString(entity, CharSetType.UTF8.getType());
}

public static void main(String[] args) throws IOException {
        HttpUtils httpUtils = new HttpUtils();
        String token = httpUtils.getToken();
        System.out.println(token);
}

响应结果：

{"access_token":"67_u22CQaWq22222222Q4griDE6kiT5hwg7jVxedn8J9te17Az1oWGGxPgB22222229Y4Wm6h_Yzci7-FSDjeH8YG6DsCOYrQXJCWsPXhT6nWbKIWCXfABACID","expires_in":7200}

2、通过 appid 和 secret 获取 token 超时 7200 秒可 redis 缓存官方文档

public String getToken() throws IOException {
        CloseableHttpClient httpClient = HttpClientBuilder.create().build();
        Map<String, Object> params = new HashMap<>();
        params.put("appid", Constants.APPLET_APP_ID);
        params.put("secret", Constants.APPLET_SECRET);
        params.put("grant_type", "client_credential");

        String url = handleParams("https://api.weixin.qq.com/cgi-bin/token", params);
        HttpGet httpGet = new HttpGet(url);

        CloseableHttpResponse response = httpClient.execute(httpGet);
        HttpEntity entity = response.getEntity(); // 响应结果

        return EntityUtils.toString(entity, CharSetType.UTF8.getType());
}

3、指定用户推送消息结束官方文档

public String pushMsg(String token) throws IOException {

        CloseableHttpClient httpClient = HttpClientBuilder.create().build();
        Map<String, Object> params = new HashMap<>();

        // 处理微信推送数据结构
        JSONObject mapData = new JSONObject();
        Map<String, Object> map1 = new HashMap<>();
        map1.put("value", "任务名称");
        mapData.put("thing2", map1);

        Map<String, Object> map2 = new HashMap<>();
        map2.put("value", "2022-04-03 10:00:00");
        mapData.put("time3", map2);

        Map<String, Object> map3 = new HashMap<>();
        map3.put("value", "描述信息");
        mapData.put("thing4", map3);

        Map<String, Object> map4 = new HashMap<>();
        map4.put("value", "备注信息");
        mapData.put("thing10", map4);

        Map<String, Object> map5 = new HashMap<>();
        map5.put("value", "任务来源");
        mapData.put("thing11", map5);

        params.put("template_id", "templateId");// 模板 id
        params.put("touser", "openId"); // open id
        params.put("data", mapData); // 数据
        params.put("page", "page"); // 点击模板卡片后的跳转页面，仅限本小程序内的页面。支持带参数,（示例index?foo=bar）。该字段不填则模板无跳转
        params.put("miniprogram_state", "trial"); //developer为开发版；trial为体验版；formal为正式版；默认为正式版
        params.put("lang", "zh_CN"); //

        HttpPost httpPost = new HttpPost("https://api.weixin.qq.com/cgi-bin/message/subscribe/send?access_token=" + token);
        httpPost.addHeader("ContentTyp", "application/json");

        // 参数转 JSON 格式
        String json = objToStr(params);
        StringEntity stringEntity = new StringEntity(json, CharSetType.UTF8.getType());
        stringEntity.setContentEncoding(CharSetType.UTF8.getType());
        httpPost.setEntity(stringEntity);

        CloseableHttpResponse response = httpClient.execute(httpPost);
        HttpEntity entity = response.getEntity(); // 响应结果
        return EntityUtils.toString(entity, CharSetType.UTF8.getType());
    }

4、完整代码

import com.alibaba.fastjson.JSONObject;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.github.chenlijia1111.utils.core.enums.CharSetType;
import org.apache.http.HttpEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.util.EntityUtils;
import org.jeecg.modules.video.utitls.Constants;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * @description:
 * @author: Mr.Fang
 * @create: 2023-04-03 17:06
 **/

public class HttpUtils {

    /**
     * description: 获取token，返回结果为 JSON 自行转 map
     * create by: Mr.Fang
     *
     * @return: java.lang.String
     * @date: 2023/4/3 17:46
     */
    public String getToken() throws IOException {
        CloseableHttpClient httpClient = HttpClientBuilder.create().build();
        Map<String, Object> params = new HashMap<>();
        params.put("appid", Constants.APPLET_APP_ID);
        params.put("secret", Constants.APPLET_SECRET);
        params.put("grant_type", "client_credential");

        String url = handleParams("https://api.weixin.qq.com/cgi-bin/token", params);
        HttpGet httpGet = new HttpGet(url);

        CloseableHttpResponse response = httpClient.execute(httpGet);
        HttpEntity entity = response.getEntity(); // 响应结果

        return EntityUtils.toString(entity, CharSetType.UTF8.getType());
    }

    /**
     * description: 获取 open id，返回结果为 JSON 自行转 map
     * create by: Mr.Fang
     *
     * @param: [code]
     * @return: java.lang.String
     * @date: 2023/4/3 17:46
     */
    public String getOpenId(String code) throws IOException {
        CloseableHttpClient httpClient = HttpClientBuilder.create().build();
        Map<String, Object> params = new HashMap<>();
        params.put("appid", Constants.APPLET_APP_ID);
        params.put("secret", Constants.APPLET_SECRET);
        params.put("js_code", code);
        params.put("grant_type", "authorization_code");

        String url = handleParams("https://api.weixin.qq.com/sns/jscode2session", params);
        HttpGet httpGet = new HttpGet(url);

        CloseableHttpResponse response = httpClient.execute(httpGet);
        HttpEntity entity = response.getEntity(); // 响应结果
        return EntityUtils.toString(entity, CharSetType.UTF8.getType());
    }

    /**
     * description: 消息推送 返回结果为 JSON 自行转 map；token 调用 getToken获取
     * create by: Mr.Fang
     *
     * @param: [token]
     * @return: java.lang.String
     * @date: 2023/4/3 17:46
     */
    public String pushMsg(String token) throws IOException {

        CloseableHttpClient httpClient = HttpClientBuilder.create().build();
        Map<String, Object> params = new HashMap<>();

        // 处理微信推送数据结构
        JSONObject mapData = new JSONObject();
        Map<String, Object> map1 = new HashMap<>();
        map1.put("value", "任务名称");
        mapData.put("thing2", map1);

        Map<String, Object> map2 = new HashMap<>();
        map2.put("value", "2023-04-03 12:00:00");
        mapData.put("time3", map2);

        Map<String, Object> map3 = new HashMap<>();
        map3.put("value", "描述信息");
        mapData.put("thing4", map3);

        Map<String, Object> map4 = new HashMap<>();
        map4.put("value", "备注系信息");
        mapData.put("thing10", map4);

        Map<String, Object> map5 = new HashMap<>();
        map5.put("value", "抖音");
        mapData.put("thing11", map5);

        params.put("template_id", "templateId");// 模板 id
        params.put("touser", "openId"); // open id
        params.put("data", mapData); // 数据
        params.put("page", "page"); // 点击模板卡片后的跳转页面，仅限本小程序内的页面。支持带参数,（示例index?foo=bar）。该字段不填则模板无跳转
        params.put("miniprogram_state", "trial"); //developer为开发版；trial为体验版；formal为正式版；默认为正式版
        params.put("lang", "zh_CN"); //

        HttpPost httpPost = new HttpPost("https://api.weixin.qq.com/cgi-bin/message/subscribe/send?access_token=" + token);
        httpPost.addHeader("ContentTyp", "application/json");

        // 参数转 JSON 格式
        String json = objToStr(params);
        StringEntity stringEntity = new StringEntity(json, CharSetType.UTF8.getType());
        stringEntity.setContentEncoding(CharSetType.UTF8.getType());
        httpPost.setEntity(stringEntity);

        CloseableHttpResponse response = httpClient.execute(httpPost);
        HttpEntity entity = response.getEntity(); // 响应结果
        return EntityUtils.toString(entity, CharSetType.UTF8.getType());
    }


    /**
     * description: 对象转 字符串
     * create by: Mr.Fang
     *
     * @param: [obj]
     * @return: java.lang.String
     * @date: 2023/4/3 17:45
     */
    public static String objToStr(Object obj) {

        ObjectMapper objectMapper = new ObjectMapper();
        if (Objects.nonNull(obj)) {
            try {
                String jsonStr = objectMapper.writeValueAsString(obj);
                return jsonStr;
            } catch (JsonProcessingException var2) {
                var2.printStackTrace();
            }
        }

        return null;
    }

    /**
     * description: map 转 URL 地址拼接
     * create by: Mr.Fang
     *
     * @param: [url, params]
     * @return: java.lang.String
     * @date: 2023/4/3 17:45
     */
    public String handleParams(String url, Map<String, Object> params) {
        if (params.size() != 0) {
            Set<Map.Entry<String, Object>> entries = params.entrySet();
            String paramsString = entries.stream().map((e) -> {
                try {
                    StringBuilder sb = new StringBuilder();
                    sb.append(URLEncoder.encode(e.getKey(), CharSetType.UTF8.getType()));
                    sb.append("=");
                    if (Objects.nonNull(e.getValue())) {
                        sb.append(URLEncoder.encode(e.getValue().toString(), CharSetType.UTF8.getType()));
                    }

                    return sb.toString();
                } catch (UnsupportedEncodingException var2) {
                    var2.printStackTrace();
                    return null;
                }
            }).collect(Collectors.joining("&"));
            return url + "?" + paramsString;
        }
        return url;
    }


}