微信通过用户openID获取UnionID

获取用户基本信息（包括UnionID机制）

开发者可通过OpenID来获取用户基本信息。请使用https协议。

接口调用请求说明
http请求方式: GET
https://api.weixin.qq.com/cgi-bin/user/info?access_token=ACCESS_TOKEN&openid=OPENID&lang=zh_CN

参数说明

参数	是否必须	说明
access_token	是	调用接口凭证
openid	是	普通用户的标识，对当前公众号唯一
lang	否	返回国家地区语言版本，zh_CN 简体，zh_TW 繁体，en 英语

所以首先需要拿到access_token才能来调用接口。 

获取access_token

接口调用请求说明

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

参数说明

参数	是否必须	说明
grant_type	是	获取access_token填写client_credential
appid	是	第三方用户唯一凭证
secret	是	第三方用户唯一凭证密钥，即appsecret

            Map params = new HashMap();
            params.put("appid", xxx);
            params.put("secret", xxx);
            params.put("grant_type", "client_credential");

            result = HttpGetUtil.httpRequestToString("https://api.weixin.qq.com/cgi-bin/token", params);
            JSONObject jsonObject = JSONObject.fromObject(result);
            access_token = jsonObject.get("access_token").toString();

拿到access_token后再去调用获取用户信息的接口

https://api.weixin.qq.com/cgi-bin/user/info?access_token=ACCESS_TOKEN&openid=OPENID&lang=zh_CN

 

Map params = new HashMap(); params.put("access_token",access_token);
params.put("lang","zh_CN");
 params.put("openid",xxx);
result = HttpGetUtil.httpRequestToString("https://api.weixin.qq.com/cgi-bin/user/info", params);
jsonObject = JSONObject.fromObject(result);
String subscribe = jsonObject.get("subscribe").toString();

注意：当subscribe为0时，说明用户未关注公众号，拉取不到其他信息。 

HttpGetUtil.java 

public class HttpGetUtil {
	 
	public static String httpRequestToString(String url, 
			Map params) {
		String result = null;
		try {
			InputStream is = httpRequestToStream(url,  params);
			BufferedReader in = new BufferedReader(new InputStreamReader(is,
					"UTF-8"));
			StringBuffer buffer = new StringBuffer();
			String line = "";
			while ((line = in.readLine()) != null) {
				buffer.append(line);
			}
			result = buffer.toString();
		} catch (Exception e) {
			return null;
		}
		return result;
	}
 
	private static InputStream httpRequestToStream(String url,
			Map params) {
		 InputStream is = null;
	        try {
	            String parameters = "";
	            boolean hasParams = false;
	            for(String key : params.keySet()){
	                String value = URLEncoder.encode(params.get(key), "UTF-8");
	                parameters += key +"="+ value +"&";
	                hasParams = true;
	            }
	            if(hasParams){
	                parameters = parameters.substring(0, parameters.length()-1);
	            }
 
 
	                url += "?"+ parameters;
	          
	            URL u = new URL(url);
	            HttpURLConnection conn = (HttpURLConnection) u.openConnection();
				conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
				conn.setRequestProperty("Accept-Charset", "UTF-8");
				conn.setRequestProperty("contentType", "utf-8");
	            conn.setConnectTimeout(50000);  
	            conn.setReadTimeout(50000);
	            conn.setDoInput(true);
	            //设置请求方式，默认为GET
	            conn.setRequestMethod("GET");
 
 
	            is = conn.getInputStream();
	        } catch (UnsupportedEncodingException e) {
	            e.printStackTrace();
	        } catch (MalformedURLException e) {
	            e.printStackTrace();
	        } catch (IOException e) {
	            e.printStackTrace();
	        }
	        return is;
	}
	
}