我可以用这个凭证 gmail api oauth2 错误做什么？

Question

I'm trying to use oauth2 to access my email and interact with the account and a desktop api-receiving and sending emails- I used the example in java with gradle https://developers.google.com/gmail/api/quickstart/java and I get this error:

Exception in thread "main" java.io.FileNotFoundException: Resource not found: C:/Users/xxx/Documents/tableaux dir/prjet email gmail/src/main/ressources/credential.json at GmailQuickstart.getCredentials(GmailQuickstart.java:50) at GmailQuickstart.main(GmailQuickstart.java:69)

What can I do please ?

The code

    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.http.javanet.NetHttpTransport;
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.gmail.Gmail;
import com.google.api.services.gmail.GmailScopes;
import com.google.api.services.gmail.model.Label;
import com.google.api.services.gmail.model.ListLabelsResponse;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.security.GeneralSecurityException;
import java.util.Collections;
import java.util.List;

/* class to demonstrate use of Gmail list labels API */
public class GmailQuickstart {
    /** Application name. */
    private static final String APPLICATION_NAME = "Gmail API Java Quickstart";
    /** Global instance of the JSON factory. */
    private static final JsonFactory JSON_FACTORY = GsonFactory.getDefaultInstance();
    /** Directory to store authorization tokens for this application. */
    private static final String TOKENS_DIRECTORY_PATH = "tokens";

    /**
     * Global instance of the scopes required by this quickstart.
     * If modifying these scopes, delete your previously saved tokens/ folder.
     */
    private static final List<String> SCOPES = Collections.singletonList(GmailScopes.GMAIL_LABELS);
    private static final String CREDENTIALS_FILE_PATH = "C:/Users/xxx/Documents/tableaux dir/prjet email gmail/src/main/ressources/credential.json";

    /**
     * Creates an authorized Credential object.
     * @param HTTP_TRANSPORT The network HTTP Transport.
     * @return An authorized Credential object.
     * @throws IOException If the credentials.json file cannot be found.
     */
    private static Credential getCredentials(final NetHttpTransport HTTP_TRANSPORT) throws IOException {
        // Load client secrets.
        InputStream in = GmailQuickstart.class.getResourceAsStream(CREDENTIALS_FILE_PATH);
        if (in == null) {
            throw new FileNotFoundException("Resource not found: " + CREDENTIALS_FILE_PATH);
        }
        GoogleClientSecrets clientSecrets = GoogleClientSecrets.load(JSON_FACTORY, new InputStreamReader(in));

        // Build flow and trigger user authorization request.
        GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(
                HTTP_TRANSPORT, JSON_FACTORY, clientSecrets, SCOPES)
                .setDataStoreFactory(new FileDataStoreFactory(new java.io.File(TOKENS_DIRECTORY_PATH)))
                .setAccessType("offline")
                .build();
        LocalServerReceiver receiver = new LocalServerReceiver.Builder().setPort(8888).build();
        Credential credential = new AuthorizationCodeInstalledApp(flow, receiver).authorize("user");
        //returns an authorized Credential object.
        return credential;
    }

    public static void main(String... args) throws IOException, GeneralSecurityException {
        // Build a new authorized API client service.
        final NetHttpTransport HTTP_TRANSPORT = GoogleNetHttpTransport.newTrustedTransport();
        Gmail service = new Gmail.Builder(HTTP_TRANSPORT, JSON_FACTORY, getCredentials(HTTP_TRANSPORT))
                .setApplicationName(APPLICATION_NAME)
                .build();

        // Print the labels in the user's account.
        String user = "me";
        ListLabelsResponse listResponse = service.users().labels().list(user).execute();
        List<Label> labels = listResponse.getLabels();
        if (labels.isEmpty()) {
            System.out.println("No labels found.");
        } else {
            System.out.println("Labels:");
            for (Label label : labels) {
                System.out.printf("- %s\n", label.getName());
            }
        }
    }
}

Answer 1

Go to google cloud console and create a cedetials.json file make sure you create it for an installed / desktop or native application.

• Create installed credetials

It will prompt you to download a json file. place this file in the directory denoted by CREDENTIALS_FILE_PATH.

In your case the file should be here with this name this is not actually the path it is the full name of the file. so make sure you dont have a different name for it or an extra .json on the end.

"C:/Users/xxx/Documents/tableaux dir/prjet email gmail/src/main/ressources/credential.json"

Answer 2

You are missing the credentials file. In the link you provided it says it is a prerequisite. Either create it and fill the values or download it from that link and paste it at the location C:/Users/xxx/Documents/tableaux dir/prjet email gmail/src/main/ressources and then change the values to your setup.

This page can help to create your credentials https://developers.google.com/workspace/guides/create-credentials

Answer 3

as said here getResourceAsStream() is returning null. Properties file is not loading the "GmailQuickstart.class.getResourceAsStream(CREDENTIALS_FILE_PATH)" function uses the class path, so it needs a relative path. So String CREDENTIALS_FILE_PATH = "credentials.json" is enough.