本文实例讲述了微信公众号获取access_token的方法。分享给大家供大家参考，具体如下：

上一版需求做了微信公众号开发，秀了一波操作，也遇到了很多坑。现在把微信公众号一些基本的操作记录一下。

微信公众号获取access_token 官方文档地址

access_token是公众号的全局唯一接口调用凭据，我们和微信服务器进行交互，服务器通过access_token判断我们是谁(哪个公众号服务的请求)。所以 我们在开发过程中服务端拿到的access_token是一定不能显式暴露给外部，否则将导致数据安全问题。别人拿到你的accessToken操作你的公众号。access_token的有效期目前为2个小时，过期需要再次获取。

下面是一种获取access_token方式

1.项目添加httpclient相关依赖，示例使用httpclient请求微信服务器，获取微信返回结果。

<!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpclient --> <dependency> <groupId>org.apache.httpcomponents</groupId> <artifactId>httpclient</artifactId> <version>4.5.3</version> </dependency> <!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpcore --> <dependency> <groupId>org.apache.httpcomponents</groupId> <artifactId>httpcore</artifactId> <version>4.4.6</version> </dependency>

2.httpClientUtil类，网上随手找的 试了一下本例的doget方法 没有问题，其他的 暂不考虑

public class HttpClientUtil { public static String doGet(String url, Map<String, String> param) { // 创建Httpclient对象 CloseableHttpClient httpclient = HttpClients.createDefault(); String resultString = ""; CloseableHttpResponse response = null; try { // 创建uri URIBuilder builder = new URIBuilder(url); if (param != null) { for (String key : param.keySet()) { builder.addParameter(key, param.get(key)); } } URI uri = builder.build(); // 创建http GET请求 HttpGet httpGet = new HttpGet(uri); // 执行请求 response = httpclient.execute(httpGet); // 判断返回状态是否为200 if (response.getStatusLine().getStatusCode() == 200) { resultString = EntityUtils.toString(response.getEntity(), "UTF-8"); } } catch (Exception e) { e.printStackTrace(); } finally { try { if (response != null) { response.close(); } httpclient.close(); } catch (IOException e) { e.printStackTrace(); } } return resultString; } public static String doGet(String url) { return doGet(url, null); } public static String doPost(String url, Map<String, String> param) { // 创建Httpclient对象 CloseableHttpClient httpClient = HttpClients.createDefault(); CloseableHttpResponse response = null; String resultString = ""; try { // 创建Http Post请求 HttpPost httpPost = new HttpPost(url); // 创建参数列表 if (param != null) { List<NameValuePair> paramList = new ArrayList<>(); for (String key : param.keySet()) { paramList.add(new BasicNameValuePair(key, param.get(key))); } // 模拟表单 UrlEncodedFormEntity entity = new UrlEncodedFormEntity(paramList,"utf-8"); httpPost.setEntity(entity); } // 执行http请求 response = httpClient.execute(httpPost); resultString = EntityUtils.toString(response.getEntity(), "utf-8"); } catch (Exception e) { e.printStackTrace(); } finally { try { response.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } return resultString; } public static String doPost(String url) { return doPost(url, null); } public static String doPostJson(String url, String json) { // 创建Httpclient对象 CloseableHttpClient httpClient = HttpClients.createDefault(); CloseableHttpResponse response = null; String resultString = ""; try { // 创建Http Post请求 HttpPost httpPost = new HttpPost(url); // 创建请求内容 StringEntity entity = new StringEntity(json, ContentType.APPLICATION_JSON); httpPost.setEntity(entity); // 执行http请求 response = httpClient.execute(httpPost); resultString = EntityUtils.toString(response.getEntity(), "utf-8"); } catch (Exception e) { e.printStackTrace(); } finally { try { response.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } return resultString; }}

3.第三步就是简单的测试代码了

public class WeChatAccessTokenTest { public static void main(String[] args) { Map<String, String> params = new HashMap<>(); // TODO: 2018/11/16 *号改成真实appid params.put("appid", "******"); // TODO: 2018/11/16 *号改成真实secret params.put("secret", "******"); params.put("grant_type", "client_credential"); String response = HttpClientUtil.doGet("https://api.weixin.qq.com/cgi-bin/token", params); JSONObject accessTokenObject = JSONObject.parseObject(response); String accessToken = accessTokenObject.getString("access_token"); Long expire = accessTokenObject.getLong("expires_in"); System.out.println(accessToken); }}

以上就是微信公众号基础却比较重要的获取access_token操作了！

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希望本文所述对大家java程序设计有所帮助。