To obtain access_token, please refer to Obtaining access_token on WeChat public platform
Because the validity period of the access_token is currently 2 hours, it needs to be refreshed regularly. Repeated acquisition will invalidate the access_token obtained last time. And the number of times to get it per day is limited, so you can do a cache. The caching method depends on your needs.
My specific code implementation is as follows:
AccessToken.java
public class AccessToken {
private String id;
private String accessToken;
private int expiresIn;
public String getAccessToken() {
return accessToken;
}
public void setAccessToken(String accessToken) {
this.accessToken = accessToken;
}
public int getExpiresIn() {
return expiresIn;
}
public void setExpiresIn(int expiresIn) {
this.expiresIn = expiresIn;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
}
AccessTokenCache.java
/**
* Singleton design mode cache accessToken expires_in
*/
public class AccessTokenCache {
//Cache the Map of accessToken, the map contains accessToken, expiresIn and the cached timestamp time
private Map<String, String> map = new HashMap<String,String>();
private static AccessTokenCache accessTokenCache = null;
private AccessTokenCache() { }
// static factory method
public static AccessTokenCache getInstance() {
if (accessTokenCache == null) {
accessTokenCache = new AccessTokenCache();
}
return accessTokenCache;
}
public Map<String, String> getMap() {
return map;
}
public void setMap(Map<String, String> map) {
this.map = map;
}
/**
* Get accessToken expires_in
* @param appid third-party user unique credentials
* @param appsecret third-party user unique credential key
* @return
*/
public Map<String,Object> getAcessTokenAndExpiresIn(String appid, String appsecret) {
Map<String,Object> result = new HashMap<String,Object>();
AccessTokenCache accessTokenCache = AccessTokenCache.getInstance();
Map<String, String> map = accessTokenCache.getMap();
String time = map.get("time");
String accessToken = map.get("access_token");
String expiresIn = map.get("expires_in");
Long nowDate = new Date().getTime();
if (accessToken != null && time != null && expiresIn!=null) {
//Set the expiration time here to the expiration time specified by WeChat minus 5 minutes
int outTime = (Integer.parseInt(expiresIn)-300) * 1000;
if (nowDate - Long.parseLong(time) < outTime) {
System.out.println("-----Read access_token from cache: " + accessToken);
// Get the data from the cache and assign the returned result
result.put("access_token", accessToken);
result.put("expires_in", expiresIn);
}
} else {
AccessToken info = WeiXinUtil.getAccessToken(appid, appsecret);//In fact, you need to call the WeChat interface yourself to get accessToken and expires_in
System.out.println("-----Get access_token by calling WeChat interface: " + info.getAccessToken());
// put the information in the cache
map.put("time", nowDate + "");
map.put("access_token", info.getAccessToken());
map.put("expires_in", info.getExpiresIn()+"");
//assign the return result
result.put("access_token", info.getAccessToken());
result.put("expires_in", info.getExpiresIn());
}
return result;
}
}
The method of calling the WeChat API to obtain the accessToken. WeiXinUtil.java
// Get the interface address of access_token (GET), limited to 2000 (times/day)
public final static String access_token_url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=APPID&secret=APPSECRET";
public class WeiXinUtil {
private static Logger log = LoggerFactory.getLogger(WeiXinUtil.class);
/**
* Get access_token
* @param appid credentials
* @param appsecret key
* @return
*/
public static AccessToken getAccessToken(String appid, String appsecret) {
AccessToken accessToken = null;
String requestUrl = WXConstants.access_token_url.replace("APPID", appid).replace("APPSECRET", appsecret);
JSONObject jsonObject = httpRequest(requestUrl, "GET", null);
// if the request was successful
if (null != jsonObject) {
try {
accessToken = new AccessToken();
accessToken.setAccessToken(jsonObject.getString("access_token"));
accessToken.setExpiresIn(jsonObject.getInt("expires_in"));
} catch (JSONException e) {
accessToken = null;
// Failed to get token
log.error("获取token失败 errcode:{} errmsg:{}", jsonObject.getInt("errcode"), jsonObject.getString("errmsg"));
}
}
return accessToken;
}
/**
* Description: initiate an https request and get the result
* @param requestUrl request address
* @param requestMethod request method (GET, POST)
* @param outputStr Submitted data
* @return JSONObject (get the attribute value of the json object by JSONObject.get(key))
*/
public static JSONObject httpRequest(String requestUrl, String requestMethod, String outputStr) {
JSONObject jsonObject = null;
StringBuffer buffer = new StringBuffer();
try {
// Create an SSLContext object and initialize it with our specified trust manager
TrustManager[] tm = { new MyX509TrustManager() };
SSLContext sslContext = SSLContext.getInstance("SSL", "SunJSSE");
sslContext.init(null, tm, new java.security.SecureRandom());
// Get the SSLSocketFactory object from the above SSLContext object
SSLSocketFactory ssf = sslContext.getSocketFactory();
URL url = new URL(requestUrl);
HttpsURLConnection httpUrlConn = (HttpsURLConnection) url.openConnection();
httpUrlConn.setSSLSocketFactory(ssf);
httpUrlConn.setDoOutput(true);
httpUrlConn.setDoInput(true);
httpUrlConn.setUseCaches(false);
// Set the request method (GET/POST)
httpUrlConn.setRequestMethod(requestMethod);
if ("GET".equalsIgnoreCase(requestMethod))
httpUrlConn.connect();
// when there is data to submit
if (null != outputStr) {
OutputStream outputStream = httpUrlConn.getOutputStream();
// Pay attention to the encoding format to prevent Chinese garbled characters
outputStream.write(outputStr.getBytes("UTF-8"));
outputStream.close();
}
// Convert the returned input stream to a string
InputStream inputStream = httpUrlConn.getInputStream();
InputStreamReader inputStreamReader = new InputStreamReader(inputStream, "utf-8");
BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
String str = null;
while ((str = bufferedReader.readLine()) != null) {
buffer.append(str);
}
bufferedReader.close();
inputStreamReader.close();
// release resources
inputStream.close();
inputStream = null;
httpUrlConn.disconnect();
jsonObject = JSONObject.fromObject(buffer.toString());
} catch (ConnectException ce) {
log.error("Weixin server connection timed out.");
} catch (Exception e) {
log.error("https request error:{}", e);
}
return jsonObject;
}
}
MyX509TrustManager.java
import javax.net.ssl.X509TrustManager;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;
/**
* Write a program to simulate an https connection and obtain a token. For https requests, we need a certificate trust manager. This manager class needs to be defined by itself, but it needs to implement the X509TrustManager interface
* description: certificate trust manager (for https requests)
*/
public class MyX509TrustManager implements X509TrustManager {
// Check client certificate
public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException {
}
// Check server side certificate
public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException {
}
// Returns an array of trusted X509 certificates
public X509Certificate[] getAcceptedIssuers() {
return null;
}
}
// You can call AccessTokenCache in the main method to get access_token
Map<String,Object> map = AccessTokenCache.getInstance().getAcessTokenAndExpiresIn(WXConstants.APPID, WXConstants.APPSECRET);
String accessToken = (String)map.get("access_token");
The console prints the result:
