什么是access_token
调用access_token请求说明
代码实现
目录
什么是access_token
微信公众平台技术文档中对access_token的解释：
access_token是公众号的全局唯一接口调用凭据，公众号调用各接口时都需使用access_token。开发者需要进行妥善保存。access_token的存储至少要保留512个字符空间。access_token的有效期目前为2个小时，需定时刷新，重复获取将导致上次获取的access_token失效。
技术文档中建议
1.使用中控服务器统一获取刷新access_token，避免不同的业务逻辑各自刷新容易引起冲突；
2.access_token中有expire_in，目前是7200秒之内的值可以根据该值控制刷新access_token，刷新过程中中控服务器可以继续对外输出老的access_token，公众平台后台会保证在5分钟内新老access_token可以继续使用；
调用access_token请求说明
使用https请求：GET
https://api./cgi-bin/token?grant_type=client_credential&appid=APPID&secret=APPSECRET
请求成功后返回JSON数据包
{"access_token":"ACCESS_TOKEN","expires_in":7200}
错误时会返回错误原因
{"errcode":40013,"errmsg":"invalidappid"}
代码实现
/** To change this license header, choose License Headers in Project Properties.* To change this template file, choose Tools | Templates* and open the template in the editor.*/package priv.liu.weichat.util;import java.io.BufferedReader;import java.io.InputStream;import java.io.InputStreamReader;import java.io.OutputStream;import .URL;import .HttpURLConnection;import .ssl.HttpsURLConnection;import net.sf.json.JSONObject;/**** @author liu*/public class HttpsUtil { /*** HttpsUtil方法https请求结果返回蔚json类型* @param Url http请求地址* @param Method http请求类型支持POST GET* @param Output* @return InputStream转换成JSONObject后返回* @throws Exception */public JSONObject HttpsUtil(String Url,String Method,String Output) throws Exception{JSONObject jsonObject = null;URL conn_url = new URL(Url);HttpURLConnection conn = (HttpsURLConnection)conn_url.openConnection();conn.setRequestMethod(Method);conn.setReadTimeout(5000);conn.setConnectTimeout(5000);conn.connect();//output获取access_token是不会用到if(Output != null){OutputStream outputstream =conn.getOutputStream();//字符集，防止出现中文乱码outputstream.write(Output.getBytes("UTF-8"));outputstream.close();}//正常返回代码为200if(conn.getResponseCode()==200){InputStream stream = conn.getInputStream();InputStreamReader inputStreamReader = new InputStreamReader(stream, "utf-8");BufferedReader bufferedReader = new BufferedReader(inputStreamReader);String str = null;StringBuffer buffer = new StringBuffer();while ((str = bufferedReader.readLine()) != null) {buffer.append(str);}bufferedReader.close();inputStreamReader.close();stream.close();conn.disconnect();jsonObject = JSONObject.fromObject(buffer.toString());}System.out.println(conn.getResponseCode());return jsonObject;} }
返回结果：{"access_token": "20_CSrzfxz8AEWg10L8BkeXj8bJfc4umpiNWnjev67oUFJWYAR-91ORgXqPHQf5EZrfauKOhH9-Gb0fd4Ev1Viz-nTkwQPl6Q0c1aV6-GVAFVL1OVnEmEa3aifjGfbvtUkrUOwmAWceT1xkkiQwGTLfAEAYLD", "expires_in": 7200}
获取到的access_token有效期只有两个小时，这块建议做个定时任务
