JAVA 整合微信公众平台，实现获取accessToken、用户授权登录

末蓝、 2023-10-15 08:06 84阅读 0赞

## 一、获取accessToken ##

### 1. 统一管理一些地址 ###

public interface WeChatConstants {
    
        // 获取全局access_token地址
        String getTokenUrl = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=%s&secret=%s";
    
        String getTicket = "https://api.weixin.qq.com/cgi-bin/ticket/getticket?access_token=%s&type=jsapi";
    
        // 获取客户信息
        String getUserUtl = "https://api.weixin.qq.com/cgi-bin/user/info";
    
        // 用户授权 获取access_token地址
        String getUserTokenUrl = "https://api.weixin.qq.com/sns/oauth2/access_token";
        //String getUserTokenUrl = "https://api.weixin.qq.com/sns/oauth2/access_token?appid=%s&secret=%s&code=%s&grant_type=authorization_code";
    
        //公众号推送消息
        String templateSendUrl = "https://api.weixin.qq.com/cgi-bin/message/template/send?access_token=";
    
        // 获取客户信息(授权版)
        String getUserInfoUrl = "https://api.weixin.qq.com/sns/userinfo";
        // appid
        String appid = "自己公众号的appid";
    
        // secret
        String secret = "自己公众号的secret";
    
    }

### 2.获取accessToken ###

public String getAccessToken() {
            //从缓存中获取
            Object obj = redisTemplate.opsForValue().get("access_token");
            if (obj != null){
                String access_token = (String)obj;
                return access_token;
            }else {
                String url = String.format(WeChatConstants.getTokenUrl, WeChatConstants.appid, WeChatConstants.secret);
                String result = NetWorkUtil.getHttpsResponse(url, "GET");
                if (StringUtils.isBlank(result)) {
                    return "";
                }
                JSONObject json = JSON.parseObject(result);
                // 获取token
                String access_token = json.getString("access_token");
                redisTemplate.opsForValue().set("access_token", access_token);
                redisTemplate.expire("access_token", 90, TimeUnit.MINUTES);//缓存一个半小时
                return access_token;
            }
        }

**因为微信公众平台每天获取accessToken的次数有限制，限额为2000次，并且每次获取都会返回新的accessToken，旧的accessToken会被刷掉。所以我们要将accessToken进行缓存，微信公众平台accessToken过期时间为2小时，我们需将缓存时间设置为小于2小时，这里设置成了一个半小时。**

## **二、用户授权登录** ##

### **1.获取用户openid** ###

public String auth(String code) {
            Map<String, Object> map = new HashMap<>();
            map.put("appid", WeChatConstants.appid);
            map.put("secret",  WeChatConstants.secret);
            map.put("code", code);
            map.put("grant_type", "authorization_code");
            //HttpUtil为hutool工具包下的
            String wxResult = HttpUtil.get(WeChatConstants.getUserTokenUrl, map);
            JSONObject object = JSONObject.parseObject(wxResult);
            String openid = (String) object.get("openid");
            return openid;
        }

### 2. 根据accessToken和openid获取用户信息 ###

public String getUser(String code) {
            String result = NetWorkUtil.getHttpsResponse(String.format(WeChatConstants.getUserTokenUrl,
                    WeChatConstants.appid,
                    WeChatConstants.secret,
                    code), "GET");
    
            JSONObject json = JSON.parseObject(result);
            String openid = json.getString("openid");
            String access_token = json.getString("access_token");
         
            // 获取用户信息
            String userInfo = NetWorkUtil.getHttpsResponse(String.format(WeChatConstants.getUserInfoUrl,
                    access_token,
                    openid), "GET");
    
            return userInfo;
        }