I am encountering the following error when attempting to access Google APIs in Java:

PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

Here is the relevant part of the code:

package utilitymon;

import com.google.api.client.auth.oauth2.Credential;
import com.google.api.client.extensions.java6.auth.oauth2.AuthorizationCodeInstalledApp;
import com.google.api.client.extensions.jetty.auth.oauth2.LocalServerReceiver;
import com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeFlow;
import com.google.api.client.googleapis.auth.oauth2.GoogleClientSecrets;
import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport;
import com.google.api.client.googleapis.json.GoogleJsonResponseException;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.json.JsonFactory;
import com.google.api.client.json.gson.GsonFactory;
import com.google.api.client.util.store.FileDataStoreFactory;
import com.google.api.services.drive.Drive;
import com.google.api.services.drive.model.File;
import com.google.api.services.sheets.v4.Sheets;
import com.google.api.services.sheets.v4.SheetsScopes;

import java.io.*;
import java.util.Arrays;
import java.util.List;

public class ReadGS {
    private static final String APPLICATION_NAME = "Google Drive API Java Quickstart";
    private static final java.io.File DATA_STORE_DIR = new java.io.File("src/main/resources/credentials");
    private static final String RESOURCE_PATH = "credentials.json";
    private static final JsonFactory JSON_FACTORY = GsonFactory.getDefaultInstance();
    private static final List<String> SCOPES = Arrays.asList(
            SheetsScopes.SPREADSHEETS,
            DriveScopes.DRIVE
    );
    private static Sheets sheetsService;
    private static FileDataStoreFactory DATA_STORE_FACTORY;
    private static HttpTransport HTTP_TRANSPORT;

    static {
        try {
            HTTP_TRANSPORT = GoogleNetHttpTransport.newTrustedTransport();
            DATA_STORE_FACTORY = new FileDataStoreFactory(DATA_STORE_DIR);
        } catch (Throwable t) {
            t.printStackTrace();
            System.exit(1);
        }
    }

    public static Credential authorize() throws Exception {
        GoogleClientSecrets clientSecrets = GoogleClientSecrets.load(
                JSON_FACTORY,
                new InputStreamReader(new FileInputStream(RESOURCE_PATH))
        );

        GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(
                HTTP_TRANSPORT,
                JSON_FACTORY,
                clientSecrets,
                SCOPES
        ).setDataStoreFactory(DATA_STORE_FACTORY).build();

        return new AuthorizationCodeInstalledApp(flow, new LocalServerReceiver()).authorize("user");
    }

    private static Drive getDriveService() throws Exception {
        Credential credential = authorize();
        return new Drive.Builder(HTTP_TRANSPORT, JSON_FACTORY, credential)
                .setApplicationName(APPLICATION_NAME)
                .build();
    }

    public static void exportSheetAsXLSX(String fileId, String exportPath) throws Exception {
        Drive driveService = getDriveService();
        try {
            File file = driveService.files().get(fileId).setFields("name, mimeType").execute();
            String fileName = file.getName();
            System.out.println("Exporting file: " + fileName);
            try (InputStream inputStream = driveService.files().export(fileId, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet").executeMediaAsInputStream();
                 FileOutputStream outputStream = new FileOutputStream(exportPath)) {
                byte[] buffer = new byte[1024];
                int bytesRead;
                while ((bytesRead = inputStream.read(buffer)) != -1) {
                    outputStream.write(buffer, 0, bytesRead);
                }
                System.out.println("Google Sheet exported as XLSX successfully to: " + exportPath);
            } catch (IOException e) {
                System.err.println("Error writing to file " + exportPath + ": " + e.getMessage());
                throw new IOException("Error exporting file " + fileId, e);
            }
        } catch (GoogleJsonResponseException e) {
            System.err.println("Google API Error while accessing file: " + fileId + " - " + e.getDetails());
            throw new Exception("Google API error during export", e);
        } catch (IOException e) {
            System.err.println("IO Error accessing file " + fileId + ": " + Arrays.toString(e.getStackTrace()));
            throw new IOException("Error accessing file " + fileId, e);
        } catch (Exception e) {
            System.err.println("Unexpected error occurred during export: " + e.getMessage());
            throw e;
        }
    }
}

And here are the dependencies I have in my pom.xml

<dependency>
    <groupId>com.google.api-client</groupId>
    <artifactId>google-api-client</artifactId>
    <version>1.33.0</version>
</dependency>
<dependency>
    <groupId>com.google.oauth-client</groupId>
    <artifactId>google-oauth-client-jetty</artifactId>
    <version>1.33.1</version>
</dependency>
<dependency>
    <groupId>com.google.apis</groupId>
    <artifactId>google-api-services-sheets</artifactId>
    <version>v4-rev614-1.18.0-rc</version>
</dependency>
<dependency>
    <groupId>com.google.apis</groupId>
    <artifactId>google-api-services-drive</artifactId>
    <version>v3-rev197-1.25.0</version>
</dependency>

Problem: The error occurs when I try to access the Google Drive API to export a Google Sheet to XLSX:

PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

This was working fine until recently, and now I'm getting the error. I've checked that my credentials are correct and that I have internet access, but I’m unsure why this error is occurring suddenly.

Steps I’ve already tried:

Updated Java and Maven dependencies. Checked my internet connection. Attempted to manually add the missing certificate to the Java truststore. Environment:

Java 11 Maven Google API Client Libraries (Google Drive, Google Sheets) Has anyone encountered this error before or have any suggestions for resolving it?

Any help would be appreciated!