[移动开发]微信小程序-获取openId/accessToken/订阅消息等接口

工具类

package test;

import com.fasterxml.jackson.databind.ObjectMapper;
import test.util.RequestSender;
importtest.response.Code2SessionResponse;
import test.response.GetAccessTokenResponse;
import test.response.SubscribeMessageSendResponse;

import java.io.IOException;
import java.net.URISyntaxException;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.HashMap;
import java.util.Map;

public class WxAppletHelper {

    /**
     * APPID
     */
    private static final String APPID = "wx6985e45642d2sdfs";

    /**
     * 秘钥
     */
    private static final String SECRET = "456648212asdfsdf5a4f6sdf4s2df1";

    /**
     * 小程序订阅消息模板ID
     */
    private static final String Template_Id = "Ru8464564asd1f2asdf456sd4fs2d1fs2fs3-Tg";

    /**
     * 扫码后跳转页
     */
    private static final String Page = "pages/index/index";

    /**
     * GET请求
     * <p>
     * 调用 auth.code2Session 接口，换取 用户唯一标识 OpenID 、 用户在微信开放平台帐号下的唯一标识UnionID（若当前小程序已绑定到微信开放平台帐号） 和 会话密钥 session_key。
     * 之后开发者服务器可以根据用户标识来生成自定义登录态，用于后续业务逻辑中前后端交互时识别用户身份
     * <p>
     * js_code，前端调用wx.login()获取的 code
     * grant_type，授权类型，此处只需填写 authorization_code
     * <p>
     * 文档地址：https://developers.weixin.qq.com/miniprogram/dev/api-backend/open-api/login/auth.code2Session.html
     */
    private static final String URL_Code2Session = "https://api.weixin.qq.com/sns/jscode2session?appid={APPID}&secret={SECRET}&js_code={JSCODE}&grant_type=authorization_code";

    /**
     * GET请求
     * <p>
     * 获取小程序全局唯一后台接口调用凭据（access_token）。调用绝大多数后台接口时都需使用 access_token，开发者需要进行妥善保存。 如使用云开发，可通过云调用免维护 access_token 调用。如使用云托管，也可以通过微信令牌/开放接口服务免维护 access_token 调用。
     * <p>
     * 文档地址：https://developers.weixin.qq.com/miniprogram/dev/api-backend/open-api/access-token/auth.getAccessToken.html
     */
    private static final String URL_GetAccessToken = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid={APPID}&secret={SECRET}";

    /**
     * POST请求
     * <p>
     * 发送订阅消息
     * <p>
     * 文档地址：https://developers.weixin.qq.com/miniprogram/dev/api-backend/open-api/subscribe-message/subscribeMessage.send.html
     */
    private static final String URL_SubscribeMessageSend = "https://api.weixin.qq.com/cgi-bin/message/subscribe/send?access_token={ACCESS_TOKEN}";


    /**
     * 登录 code2Session,获取openId等信息
     *
     * @param code 前端调用wx.login()获取的 code
     */
    public static Code2SessionResponse authCode2Session(String code) throws IOException, URISyntaxException {
        RequestSender requestSender = RequestSender.builder().url(URL_Code2Session.replace("{APPID}", APPID).replace("{SECRET}", SECRET).replace("{JSCODE}", code)).build();
        requestSender.doRequest();
        String result = requestSender.getResult();
        Code2SessionResponse code2SessionResponse = new ObjectMapper().readValue(result, Code2SessionResponse.class);

        return code2SessionResponse;
    }

    /**
     * 接口调用凭证 getAccessToken
     *
     * @return
     * @throws IOException
     * @throws URISyntaxException
     */
    public static GetAccessTokenResponse getAccessToken() throws IOException, URISyntaxException {
        RequestSender requestSender = RequestSender.builder().url(URL_GetAccessToken.replace("{APPID}", APPID).replace("{SECRET}", SECRET)).build();
        requestSender.doRequest();
        String result = requestSender.getResult();
        GetAccessTokenResponse accessTokenResponse = new ObjectMapper().readValue(result, GetAccessTokenResponse.class);

        return accessTokenResponse;
    }

    /**
     * 订阅消息
     *
     * @param
     * @return
     * @throws IOException
     * @throws URISyntaxException
     */
    public static SubscribeMessageSendResponse subscribeMessageSend(String openId, Map<String, Object> params) throws IOException, URISyntaxException {
        GetAccessTokenResponse accessToken = getAccessToken();

        RequestSender requestSender = RequestSender.builder()
                .url(URL_SubscribeMessageSend.replace("{ACCESS_TOKEN}", accessToken.getAccess_token()))
                .method("POST")
                .jsonFormated(true)
                .param("touser", openId)
                .param("template_id", Template_Id)
                .param("page", Page)
                .param("data", params)
                .build();

        requestSender.doRequest();
        String result = requestSender.getResult();
        SubscribeMessageSendResponse subscribeMessageSendResponse = new ObjectMapper().readValue(result, SubscribeMessageSendResponse.class);

        return subscribeMessageSendResponse;
    }

    public static void main(String[] args) throws IOException, URISyntaxException {
        //测试获取Code2SessionResponse，包含openId等信息
        Code2SessionResponse code2SessionResponse = WxAppletHelper.authCode2Session("12345");
        System.out.println(code2SessionResponse.toString());

        //测试订阅消息推送，注意参数格式，参考微信文档
        Map<String, Object> params = new HashMap<String, Object>();
        String time = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss").format(LocalDateTime.now());
        params.put("date1", new HashMap<String, Object>() {
            {
                put("value", time);
            }
        });
        params.put("thing1", new HashMap<String, Object>() {
            {
                put("value", "消息已回复，请查看详情");
            }
        });
        WxAppletHelper.subscribeMessageSend("oX5-i5Te8rGikPNstFKH47G1ufp8", params);
    }
}

各接口响应数据类

package test.response;

import lombok.Data;
import lombok.ToString;

@Data
@ToString
public class Code2SessionResponse {

    /**
     * 用户唯一标识
     */
    private String openid;

    /**
     * 会话密钥
     */
    private String session_key;

    /**
     * 用户在开放平台的唯一标识符，若当前小程序已绑定到微信开放平台帐号下会返回，详见 UnionID 机制说明。
     */
    private String unionid;

    /**
     * 错误码值
     */

    private Integer errcode;

    /**
     * 错误信息
     */
    private String errmsg;
}

package test.response;

import lombok.Data;
import lombok.ToString;

@Data
@ToString
public class GetAccessTokenResponse {

    /**
     * 用户唯一标识
     */
    private String access_token;

    /**
     * 会话密钥
     */
    private Long expires_in;

    /**
     * 错误码值
     */
    private Integer errcode;

    /**
     * 错误信息
     */
    private String errmsg;
}

package test.response;

import lombok.Data;
import lombok.ToString;

@Data
@ToString
public class SubscribeMessageSendResponse {

    /**
     * 错误码值
     */
    private Integer errcode;

    /**
     * 错误信息
     */
    private String errmsg;
}

其中的RequestSender工具类的使用，参照该文章HttpClient的使用

其他微信公众平台使用小程序时需要配置的内容

    @GetMapping("/get")
    public void get(HttpServletRequest request, HttpServletResponse response) throws IOException {

        System.out.println("==================get====================");
        Map<String, String[]> parameterMap = request.getParameterMap();
        if(parameterMap != null && !parameterMap.isEmpty()){
            Set<Map.Entry<String, String[]>> entries = parameterMap.entrySet();

            for(Map.Entry<String,String[]> entry : entries){
                System.out.println(entry.getKey() + ":" + Arrays.toString(entry.getValue()));
            }
        }

        String echostr = request.getParameter("echostr");

        response.getWriter().print(echostr == null ? "" : echostr);
    }

    @PostMapping("/post")
    public void post(HttpServletRequest request, HttpServletResponse response) throws IOException {

        System.out.println("==================post====================");
        Map<String, String[]> parameterMap = request.getParameterMap();
        if(parameterMap != null && !parameterMap.isEmpty()){
            Set<Map.Entry<String, String[]>> entries = parameterMap.entrySet();

            for(Map.Entry<String,String[]> entry : entries){
                System.out.println(entry.getKey() + ":" + Arrays.toString(entry.getValue()));
            }
        }

        response.getWriter().print("success");
    }