I'm using Google API in Java and have the following code snippets.
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.FileInputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.security.GeneralSecurityException;
import java.util.Collections;
import java.util.List;
import java.lang.Object;
import java.util.ArrayList;
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.jackson2.JacksonFactory;
import com.google.api.client.util.store.FileDataStoreFactory;
import com.google.api.services.drive.Drive;
import com.google.api.services.drive.Drive.Files;
import com.google.api.services.drive.DriveScopes;
import com.google.api.services.drive.model.File;
import com.google.api.services.drive.model.FileList;
public class DriveQuickstart {
private static final String APPLICATION_NAME = "DriveQuickstart";
private static final JsonFactory JSON_FACTORY = JacksonFactory.getDefaultInstance();
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(DriveScopes.DRIVE_METADATA_READONLY);
private static final String CREDENTIALS_FILE_PATH = "C:/Quickstart/src/main/resources/client_secret.json";
// * Creates an authorized Credential object.
// * @param HTTP_TRANSPORT The network HTTP Transport.
// * @return An authorized Credential object.
// * @throws IOException If the client_secret.json file cannot be found.
// */
private static Credential getCredentials(final NetHttpTransport HTTP_TRANSPORT) throws IOException {
// Load client secrets.
InputStream in = new FileInputStream(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();
return new AuthorizationCodeInstalledApp(flow, receiver).authorize("user");
}
public static void main(String[] args) throws IOException, GeneralSecurityException {
try
{
// Build a new authorized API client service.
System.out.println("This is a test line");
//declare final variable NetHttpTransport and GoogleNetHttpTransport from import statements
final NetHttpTransport HTTP_TRANSPORT = GoogleNetHttpTransport.newTrustedTransport();
System.out.println("This is the second test line");
Drive service = new Drive.Builder(HTTP_TRANSPORT, JSON_FACTORY, getCredentials(HTTP_TRANSPORT))
.setApplicationName(APPLICATION_NAME)
.build();
System.out.println("This is the third test line");
// Print the names and IDs for files.
FileList result = service.files().list()
.setPageSize(10)
.setFields("nextPageToken, files(id, name)")
.execute();
List<File> files = result.getFiles();
if (files == null || files.isEmpty()) {
System.out.println("No files found.");
} else {
System.out.println("Files:");
for (File file : files) {
System.out.printf("%s (%s)\n", file.getName(), file.getId());
}
}
Drive.Files var1 = service.files();
System.out.println("var1 = " + var1.toString());
Drive.Files.List var2 = var1.list();
if (var2 == null)
System.out.println("null");
else {
System.out.printf("Var2 size is: %d\n", var2.size() );
}
//iterate through map and print results
}
catch(Exception e){
System.out.println("error");
}
System.out.println("This is the fourth test line");
}
}
}
To go more into detail. I'm using a somewhat unconventional method to try it. I'm using only command line to run (no IDEs, no gradle).
Here is a link to an ss with my output in command prompt. cmd output
Assuming that I am actually accessing the metadata in Google Drive, and that the Drive.Files is nested inside an Abstract Map (java.util.AbstractMap), I should be able to return the size of the map to get an idea of where it it searching by how many files it is returning.
I'm not sure what is going on. First time I compile and run, I get the tab opening in chrome asking for permission to gain access to metadata to drive. Second time, it gives the "WARNING: unable to change permissions for everybody: " errors. On top of that, var1 ('set to service.files()') returns com.google.api.services.drive.Drive$Files@458ad742 when using toString(). The subclass service.files().list() assigned to var2 should return a list of files in my Google Drive, but apparently it is not doing so.
I may be misunderstanding a lot of stuff, so bear with me. Thanks for the help.
In case people ask, I have tried the tutorial here https://developers.google.com/drive/api/v3/quickstart/java It opened the tab to ask for metadata access to google drive on whichever google account I selected.
So from that alone, I (think) connected to Google Drive. However, the default code that is supposed to list the names and ids of 10 files doesn't do anything.
How am I running the program: Here is the batch file that I'm using to compile and run the code in cmd.
jar cfe DriveQuickstart.jar Quickstart DriveQuickstart.class
javac -cp ./* DriveQuickstart.java
java -cp ./* DriveQuickstart
For some reason I don't know/understand, this was the only way that wouldn't return methods from the imported jar files not existing.
