Java to obtain OpenID

<dependency>  
    <groupId></groupId>  
    <artifactId>alipay-sdk-java</artifactId>  
    <version>Latest version number</version>  
</dependency>

import ;  
import ;  
import ;  
import ;  
  
@Configuration  
public class AlipayConfig {  
  
    // Application ID    private static final String APP_ID = "Our AppID";  
    // Merchant private key    private static final String PRIVATE_KEY = "Our Private Key";  
    // Alipay public key    private static final String ALIPAY_PUBLIC_KEY = "Alipay's public key";  
    // The server asynchronous notification page path requires the complete path in the format http:// format. You cannot add custom parameters such as ?id=123. It must be accessed normally by the external network.    private static final String NOTIFY_URL = "/notify_url.jsp";  
    // Page jump synchronous notification page path requires the complete path of http:// format, and cannot add custom parameters such as ?id=123, and must be accessed normally by the external network.    private static final String RETURN_URL = "/return_url.jsp";  
    // Signature method    private static final String SIGN_TYPE = "RSA2";  
    // Character encoding format    private static final String CHARSET = "utf-8";  
    // Alipay gateway    private static final String GATEWAY_URL = "/";  
  
    @Bean  
    public AlipayClient alipayClient() {  
        return new DefaultAlipayClient(GATEWAY_URL, APP_ID, PRIVATE_KEY, "json", CHARSET, ALIPAY_PUBLIC_KEY, SIGN_TYPE);  
    }  
}

// Here we assume that we already have the authorization code (auth_code), which is usually included when Alipay redirects back to our callback address after the user authorizationString authCode = "Auth_code returned after user authorization";  
AlipayClient alipayClient = alipayClient(); // Inject AlipayClient  
// Use AlipayClient to call API to get access_token and user information// Note: This is just an example. When actually calling the API, you need to build the correct request parameters based on Alipay's API documentation.// In real scenarios, we may need to use the execute method of AlipayClient and pass in a request object that implements the AlipayRequest interface.// The following code needs to be adjusted according to actual situation  
// Suppose that access_token has been obtained through auth_code, and the interface is called to obtain user information using access_tokenString accessToken = "Our access_token"; // Example// Call the interface to obtain user information, which may contain user_id (similar to OpenID)// Note: The detailed code for calling the API is omitted here, because the request needs to be built according to Alipay's API documentation  
String userId = "User_id obtained through API call"; // Assume this is throughAPIThe user obtained after the callID（user_id），It is similar to Alipay ecosystemOpenID，Used to uniquely identify users

// Suppose we have obtained auth_code in some wayString authCode = "Auth_code obtained from callback URL";  
  
// Use AlipayClient and auth_code to exchange for access_token (the detailed API call code is omitted here)// Usually we need to build a request object that meets the requirements of Alipay and use the execute method of AlipayClient to send the requestString accessToken = exchangeAuthCodeForAccessToken(authCode); // This is a hypothetical method  
// Use access_token to call the user information API to obtain user_id (the detailed API calling code is also omitted)String userId = getUserIdByAccessToken(accessToken); // This is also a hypothetical method  
// Now that we have the user_id of the user, we can use it in our system("User ID: " + userId);  
  
// ...（Omitted hereexchangeAuthCodeForAccessTokenandgetUserIdByAccessTokenImplementation details）