从谷歌服务帐户获取嵌入api的access_token

import java.io.FileInputStream;
import java.io.IOException;
import java.security.GeneralSecurityException;
import java.util.Collections;

import com.google.auth.oauth2.GoogleCredentials;
import com.google.auth.http.HttpCredentialsAdapter;
import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport;
import com.google.api.client.json.jackson2.JacksonFactory;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.json.JsonFactory;

public class GoogleAccessToken {
    public static void main(String[] args) throws IOException, GeneralSecurityException {
        // 替换为JSON密钥文件的路径
        String jsonKeyFilePath = "/path/to/your/keyfile.json";

        // 创建GoogleCredentials实例
        GoogleCredentials credentials = GoogleCredentials.fromStream(new FileInputStream(jsonKeyFilePath))
             .createScoped(Collections.singleton("https://www.googleapis.com/auth/sqlservice.admin"));

        // 获取HttpTransport和JsonFactory实例
        HttpTransport httpTransport = GoogleNetHttpTransport.newTrustedTransport();
        JsonFactory jsonFactory = JacksonFactory.getDefaultInstance();

        // 创建访问令牌
        String accessToken = credentials.getAccessToken().getTokenValue();

        System.out.println("Access token: " + accessToken);
    }
}