Java: 小程序获取用户开放信息(OpenId,UnionID)

关于OpenId和UnionID

OpenId是用户唯一标识.也就是用户信息的主键.

UnionID 机制说明
如果开发者拥有多个移动应用、网站应用、和公众帐号（包括小程序），可通过 UnionID 来区分用户的唯一性，因为只要是同一个微信开放平台帐号下的移动应用、网站应用和公众帐号（包括小程序），用户的 UnionID 是唯一的。换句话说，同一用户，对同一个微信开放平台下的不同应用，UnionID是相同的。

获取流程

UnionID只有满足条件时才会返回.

优化后流程(小程序减少请求一次后台)

在小程序启动时,会运行app.js里面的onLaunch方法.获取信息从onLaunch方法开始:

1. 在调用 wx.login时将res.code缓存到this.globalData.privateUserCode中,在后面使用;
2. 获取用户信息的时候: wx.getSetting中调用wx.getUserInfo(需要附加参数: withCredentials: true,)时,将res.code,encryptedData,iv这三个数据发送给后台,用来换取OpenId和UnionID().

未优化流程

1. 用wx.login中的res.code换取session_key,OpenId;
2. 用session_key,iv,encryptedData解密出UnionID

微信小程序中的修改

app.js

返回结果信息格式(仅供参考):

{
    "code":"0",
    "data":{
        "city":"xxxxxxxxxxxx",
        "province":"xxxxxxxxxxxx",
        "country":"China",
        "watermark":{
            "appid":"xxxxxxxxxxxx",
            "timestamp":"xxxxxxxxxxxx"
        },
        "openId":"xxxxxxxxxxxx",
        "nickName":"xxxxxxxxxxxx",
        "avatarUrl":"xxxxxxxxxxxx",
        "unionId":null
    },
    "message":""
}

修改参考:

App({
  onLaunch: function () {

    wx.getSystemInfo({
      success: e => {
      }
    })
    // 展示本地存储能力
    var logs = wx.getStorageSync('logs') || []
    logs.unshift(Date.now())
    wx.setStorageSync('logs', logs)

    // 登录
    wx.login({
      success: res => {
        console.log(res);
        if (res && res.code) {
          this.globalData.privateUserCode = res.code;
        }
        // 发送 res.code 到后台换取 openId, sessionKey, unionId
      }
    })
    // 获取用户信息
    wx.getSetting({
      success: res => {
        if (res.authSetting['scope.userInfo']) {
          // 已经授权，可以直接调用 getUserInfo 获取头像昵称，不会弹框
          wx.getUserInfo({
            withCredentials: true,
            success: res => {
              // 可以将 res 发送给后台解码出 unionId
              this.globalData.userInfo = res.userInfo
              if (res && res.encryptedData && res.iv && this.globalData.privateUserCode) {
                const postData = {
                  openCode: this.globalData.privateUserCode,
                  encryptedData: res.encryptedData,
                  iv: res.iv
                }
                wx.request({
                  url:'http://localhost:8080/getWeChatUnionIdAndOpenId',
                  data: postData,
                  method: "POST",
                  header: {
                    'content-type': 'application/x-www-form-urlencoded' //修改此处即可
                  },
                  success: decodeData => {
                      try {
                        const objInfo = decodeData.data;
                        if (objInfo.code == "0") {
                          this.globalData.constWxUserOpenId = objInfo.data.openId;
                          this.globalData.constWxUserUnionId=objInfo.data.unionId;
                        } else {
                          console.error(`获取微信UNIONID返回结果处理错误,错误信息: ${objInfo.message}`);
                        }
                      } catch (err) {
                        console.error(`获取微信UNIONID错误,错误信息: ${err}`);
                      }
                  }
                })
              }
              // 由于 getUserInfo 是网络请求，可能会在 Page.onLoad 之后才返回
              // 所以此处加入 callback 以防止这种情况
              if (this.userInfoReadyCallback) {
                this.userInfoReadyCallback(res)
              }
            }
          })
        }
      }
    })
  },
  globalData: {
    userInfo: null,
    extUserInfo: null,
    privateUserCode: null,
  }
})

Java服务端

此处需使用Java JDK 14或高于14的版本,采用Spring Boot搭建.

在application.properties中配置小程序相关信息

application.properties文件中修改小程序appid和小程序秘钥:

#################################### common config : ####################################
spring.application.name=wxopenid
# 应用服务web访问端口
server.port=8080
# ActuatorWeb访问端口
management.server.port=8081
management.endpoints.jmx.exposure.include=*
management.endpoints.web.exposure.include=*
management.endpoint.health.show-details=always
#************************************************
# 微信小程序-配置信息
cn.bckf.wechat.appid=配置你自己的小程序appid
cn.bckf.wechat.secret=配置你自己的小程序秘钥
logging.level.cn.bckf=debug

将配置文件中的信息注入到Java Bean

import lombok.Data;
import lombok.NoArgsConstructor;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;

/**
 * 读取application.properties文件中的微信小程序相关信息.
 *
 */
@Component
@ConfigurationProperties(prefix = "cn.bckf.wechat")
@Data
@NoArgsConstructor
public class SystemInfo {

    String appId;

    String secret;
}

JSON数据处理

访问微信的接口,微信会返回json数据,在Java中,需要对json数据进行解析处理.

import com.fasterxml.jackson.annotation.JsonProperty;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;


/**
 * 微信解密数据实体类.(字段可能会增加)
 * (参考地址: https://developers.weixin.qq.com/miniprogram/dev/framework/open-ability/signature.html)
 *
 * @author prd
 * @version 2020-05-16
 */
@AllArgsConstructor
@NoArgsConstructor
@Data
public class WeChatDecryptData {


    @JsonProperty("openId")
    private String openid;
    @JsonProperty("nickName")
    private String nickname;
    private String gender;
    private String city;
    private String province;
    private String country;
    @JsonProperty("avatarUrl")
    private String avatarUrl;
    @JsonProperty("unionId")
    private String unionId;
    private Watermark watermark;

    public class Watermark {
        private String appid;
        private String timestamp;

        public void setAppid(String appid) {
            this.appid = appid;
        }

        public String getAppid() {
            return appid;
        }

        public void setTimestamp(String timestamp) {
            this.timestamp = timestamp;
        }

        public String getTimestamp() {
            return timestamp;
        }
    }
}




import com.fasterxml.jackson.annotation.JsonProperty;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@AllArgsConstructor
@NoArgsConstructor
public class WeChatOpenIdRes {

    @JsonProperty("session_key")
    private String sessionKey;
    private String openid;

}

解密及调用微信接口

该类中主要定义了解密方法,请求微信接口.

关于解密,也可以参考微信官方文档: https://developers.weixin.qq.com/miniprogram/dev/framework/open-ability/signature.html

import lombok.extern.slf4j.Slf4j;
import org.springframework.util.StringUtils;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.io.IOException;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.util.Base64;

/**
 * 解密及调用微信接口工具
 *
 *
 */
@Slf4j
public class WebUtil {
    /**
     * 解密微信加密信息获取UnionId.
     */
    private static int AES_128 = 128;
    private static String ALGORITHM = "AES";
    private static String AES_CBS_PADDING = "AES/CBC/PKCS5Padding";

    public static byte[] encrypt(final byte[] key, final byte[] IV, final byte[] message) throws Exception {
        return encryptDecrypt(Cipher.ENCRYPT_MODE, key, IV, message);
    }

    public static byte[] decrypt(final byte[] key, final byte[] IV, final byte[] message) throws Exception {
        return encryptDecrypt(Cipher.DECRYPT_MODE, key, IV, message);
    }

    private static byte[] encryptDecrypt(final int mode, final byte[] key, final byte[] IV, final byte[] message)
            throws Exception {
        final Cipher cipher = Cipher.getInstance(AES_CBS_PADDING);
        final SecretKeySpec keySpec = new SecretKeySpec(key, ALGORITHM);
        final IvParameterSpec ivSpec = new IvParameterSpec(IV);
        cipher.init(mode, keySpec, ivSpec);
        return cipher.doFinal(message);
    }

    private static String getWeChatAPI() {
        return "https://api.weixin.qq.com/sns/jscode2session?appid=%s&secret=%s&js_code=%s&grant_type=authorization_code";
    }


    /**
     * 解密微信加密的数据(获取UnionId及其余相关信息).
     *
     * @param sessionKey
     * @param encryptedData
     * @param iv
     * @return
     */
    public static String decryptWeChatInfo(String sessionKey, String encryptedData, String iv) {
        if (StringUtils.hasText(sessionKey) && StringUtils.hasText(encryptedData) && StringUtils.hasText(iv)) {
            try {
                var decodeSessionKey = Base64.getDecoder().decode(sessionKey);
                var decodeEncryptedData = Base64.getDecoder().decode(encryptedData);
                var deCodeIV = Base64.getDecoder().decode(iv);
                var keyGenerator = KeyGenerator.getInstance(ALGORITHM);
                keyGenerator.init(AES_128);
                var decryptedString = decrypt(decodeSessionKey, deCodeIV, decodeEncryptedData);
                var resStr = new String(decryptedString);
                log.debug("解密结果 : {}",resStr);
                return resStr;
            } catch (Exception ex) {
                log.debug("________________________________decryptWeChatInfo: sessionKey:{},encryptedData: {} , iv: {}", sessionKey, encryptedData, iv);
            }
        }
        return null;
    }


    /**
     * 用微信小程序获得的code换取微信用户的openId.
     *
     * @param weChatOpenCode 微信小程序获得的code.
     * @return
     */
    public static String getWeChatOpenId(String weChatOpenCode, String appId, String secret) {
        log.debug("________________________________wxOpenCode:{}", weChatOpenCode);
        if (!StringUtils.hasLength(weChatOpenCode)) {
            return "";
        }
        try {
            var client = HttpClient.newHttpClient();
            var url = getWeChatAPI().formatted(appId, secret, weChatOpenCode);
            HttpRequest request = HttpRequest.newBuilder()
                    .uri(URI.create(url))
                    .build();
            var response = client.send(request, HttpResponse.BodyHandlers.ofString());
            log.info(response.body());
            return response.body();
        } catch (IOException e) {
            log.error("getWeChatOpenId:{}", e.getMessage());
        } catch (InterruptedException e) {
            log.error("getWeChatOpenId:{}", e.getMessage());
        }
        return "";
    }


}

对外提供服务

对外提供访问服务:

/appid 可以访问当前application.properties配置的小程序相关信息.
/getWeChatOpenId 微信loginCode获取微信用户的openId
/getWeChatUnionId 解密微信加密的数据(获取UnionId)(关于UnionId的限制请参考官方文档).
(推荐,只需调用一次即可同时获得UnionId和OpenId) /getWeChatUnionIdAndOpenId 解密微信加密的数据(获取UnionId和OpenId).(用loginCode换取OpenId然后换取UnionId)(关于UnionId的限制请参考官方文档).

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.Map;


/**
 * 微信小程序服务端解密用户的OpenId和UnionId.
 * 
 * 基本参考: JDK>=14
 * 
 * 参考文档:
 * 
 * 服务端获取开放数据:
 * 
 * https://developers.weixin.qq.com/miniprogram/dev/framework/open-ability/signature.html
 * 
 * UnionID 机制说明:
 * 
 * https://developers.weixin.qq.com/miniprogram/dev/framework/open-ability/union-id.html
 *
 * @author prd
 * @version 2020-05-16
 */
@SpringBootApplication
@RestController
@RequestMapping("/")
@Slf4j
public class WeChatOpenDataDecryptApplication {

    @Autowired
    private ObjectMapper objectMapper;

    @Autowired
    private SystemInfo systemInfo;

    @RequestMapping("/appid")
    public SystemInfo getAppId() {
        return systemInfo;
    }


    /**
     * 用微信loginCode获取微信用户的openId.
     *
     * @param loginCode
     * @return
     */
    @RequestMapping("getWeChatOpenId")
    public String getWeChatOpenId(String loginCode) {
        return WebUtil.getWeChatOpenId(loginCode, systemInfo.getAppId(), systemInfo.getSecret());
    }


    /**
     * 返回UnionId,通用方法.
     *
     * @param resStr
     * @return
     * @throws JsonProcessingException
     */
    private Map getUnionIdCommon(String resStr) throws JsonProcessingException {
        if (StringUtils.hasText(resStr)) {
            var resObj = objectMapper.readValue(resStr, WeChatDecryptData.class);
            var waterMarkAppId = resObj.getWatermark().getAppid();
            var currentWxAppId = systemInfo.getAppId();
            if (waterMarkAppId.equalsIgnoreCase(currentWxAppId)) {
                return Map.of("code", "0", "message", "", "data", resObj);
            } else {
                var resMessage = String.format("解密微信加密的数据(获取UnionId).发生错误,错误原因: 解密后的APPID与当前小程序的APPID不一致!解密后的APPID: %s,当前APPID: %s.", waterMarkAppId, currentWxAppId);
                log.error("解密微信加密的数据(获取UnionId).发生错误,错误原因: 解密后的APPID与当前小程序的APPID不一致!解密后的APPID: {},当前APPID: {}.", waterMarkAppId, currentWxAppId);
                return Map.of("code", "-1", "message", resMessage);
            }
        }
        return Map.of("code", "-1", "message", "返回数据为空,或处理出现错误!");
    }

    /**
     * 解密微信加密的数据(获取UnionId)(关于UnionId的限制请参考官方文档).
     *
     * @param encryptedData
     * @param sessionKey
     * @param iv
     * @return
     */
    @RequestMapping("getWeChatUnionId")
    public Map getWeChatUnionId(String sessionKey, String encryptedData, String iv) {
        try {
            var resStr = WebUtil.decryptWeChatInfo(sessionKey, encryptedData, iv);
            return getUnionIdCommon(resStr);
        } catch (Exception ex) {
            return Map.of("code", "-1", "message", "处理出现错误!错误信息: " + ex.getMessage());
        }
    }


    /**
     * 解密微信加密的数据(获取UnionId和OpenId).(用loginCode换取OpenId然后换取UnionId)(关于UnionId的限制请参考官方文档).
     *
     * @param encryptedData
     * @param iv
     * @param loginCode
     * @return
     */
    @RequestMapping("getWeChatUnionIdAndOpenId")
    public Map getWeChatUnionIdAndOpenId(String encryptedData, String iv, String loginCode) {
        try {
            if (!StringUtils.hasText(loginCode) || !StringUtils.hasText(encryptedData) || !StringUtils.hasText(iv)) {
                return Map.of("code", "-1", "message", "必填参数为空!");
            }
            var openIdRes = WebUtil.getWeChatOpenId(loginCode, systemInfo.getAppId(), systemInfo.getSecret());
            if (StringUtils.hasText(openIdRes)) {
                var wxOpenIdResObj = objectMapper.readValue(openIdRes, WeChatOpenIdRes.class);
                if (wxOpenIdResObj != null) {
                    var resStr1 = WebUtil.decryptWeChatInfo(wxOpenIdResObj.getSessionKey(), encryptedData, iv);
                    return getUnionIdCommon(resStr1);
                }
            }
        } catch (Exception ex) {
            return Map.of("code", "-1", "message", "处理出现错误!错误信息: " + ex.getMessage());
        }
        return Map.of("code", "-1", "message", "返回数据为空,或处理出现错误!");
    }


    public static void main(String[] args) {
        SpringApplication.run(WeChatOpenDataDecryptApplication.class, args);
    }

}

项目地址

完整代码可以访问: https://gitee.com/pruidong/SpringBootDemoProjects/tree/master/WeChatGetOpenIdDemo