GmailApiQuickstart -
I am embarrassed that I'm simply failing with an example piece of code, but I'll blame it on the fact that it is late...
I have taken a copy and paste of: https://developers.google.com/gmail/api/quickstart/quickstart-java and downloaded the client libraries: https://code.google.com/p/google-api-java-client/ and https://developers.google.com/api-client-library/java/apis/gmail/v1
When I run the sample, I get the following exception:
Exception in thread "main" java.lang.IllegalArgumentException
at com.google.api.client.repackaged.com.google.common.base.Preconditions.checkArgument(Preconditions.java:76)
at com.google.api.client.util.Preconditions.checkArgument(Preconditions.java:37)
at com.google.api.client.googleapis.auth.oauth2.GoogleClientSecrets.getDetails(GoogleClientSecrets.java:82)
at com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeFlow$Builder.<init>(GoogleAuthorizationCodeFlow.java:195)
at com.emailreply.musterion.GmailApiQuickstart.main(GmailApiQuickstart.java:40)
Googling, I can't find a simple answer, so am assuming stupidity or a library missing/incorrect.
The libraries as I have them are:
/libs/commons-logging-1.1.1.jar
/libs/google-api-client-1.19.0.jar
/libs/google-api-client-android-1.19.0.jar
/libs/google-api-client-appengine-1.19.0.jar
/libs/google-api-client-gson-1.19.0.jar
/libs/google-api-client-jackson2-1.19.0.jar
/libs/google-api-client-java6-1.19.0.jar
/libs/google-api-client-servlet-1.19.0.jar
/libs/google-http-client-1.19.0.jar
/libs/google-http-client-android-1.19.0.jar
/libs/google-http-client-appengine-1.19.0.jar
/libs/google-http-client-gson-1.19.0.jar
/libs/google-http-client-jackson2-1.19.0.jar
/libs/google-http-client-jdo-1.19.0.jar
/libs/google-oauth-client-1.19.0.jar
/libs/google-oauth-client-appengine-1.19.0.jar
/libs/google-oauth-client-java6-1.19.0.jar
/libs/google-oauth-client-jetty-1.19.0.jar
/libs/google-oauth-client-servlet-1.19.0.jar
/libs/gson-2.1.jar
/libs/httpclient-4.0.1.jar
/libs/httpcore-4.0.1.jar
/libs/jackson-core-2.1.3.jar
/libs/jdo2-api-2.3-eb.jar
/libs/jetty-6.1.26.jar
/libs/jetty-util-6.1.26.jar
/libs/jsr305-1.3.9.jar
/libs/transaction-api-1.1.jar
google-api-services-gmail-v1-rev10-1.19.0.jar
The example mentioned above:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.List;
import com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeFlow;
import com.google.api.client.googleapis.auth.oauth2.GoogleClientSecrets;
import com.google.api.client.googleapis.auth.oauth2.GoogleCredential;
import com.google.api.client.googleapis.auth.oauth2.GoogleOAuthConstants;
import com.google.api.client.googleapis.auth.oauth2.GoogleTokenResponse;
import com.google.api.client.http.HttpTransport;
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.services.gmail.Gmail;
import com.google.api.services.gmail.model.ListThreadsResponse;
import com.google.api.services.gmail.model.Thread;
public class GmailApiQuickstart {
// Check https://developers.google.ciom/gmail/api/auth/scopes for all available scopes
private static final String SCOPE = "https://www.googleapis.com/auth/gmail.readonly";
private static final String APP_NAME = "Gmail API Quickstart";
// Email address of the user, or "me" can be used to represent the currently authorized user.
private static final String USER = "me";
// Path to the client_secret.json file downloaded from the Developer Console
private static final String CLIENT_SECRET_PATH = "./client_secret.json";
public static void main (String [] args) throws IOException {
HttpTransport httpTransport = new NetHttpTransport();
JsonFactory jsonFactory = new JacksonFactory();
GoogleClientSecrets clientSecrets = GoogleClientSecrets.load(jsonFactory, new BufferedReader(new InputStreamReader(GmailApiQuickstart.class.getResourceAsStream(CLIENT_SECRET_PATH))));
// Allow user to authorize via url.
GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(
httpTransport, jsonFactory, clientSecrets, Arrays.asList(SCOPE))
.setAccessType("online")
.setApprovalPrompt("auto").build();
String url = flow.newAuthorizationUrl().setRedirectUri(GoogleOAuthConstants.OOB_REDIRECT_URI).build();
System.out.println("Please open the following URL in your browser then type the authorization code:\n" + url);
// Read code entered by user.
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String code = br.readLine();
// Generate Credential using retrieved code.
GoogleTokenResponse response = flow.newTokenRequest(code)
.setRedirectUri(GoogleOAuthConstants.OOB_REDIRECT_URI).execute();
GoogleCredential credential = new GoogleCredential()
.setFromTokenResponse(response);
// Create a new authorized Gmail API client
Gmail service = new Gmail.Builder(httpTransport, jsonFactory, credential)
.setApplicationName(APP_NAME).build();
// Retrieve a page of Threads; max of 100 by default.
ListThreadsResponse threadsResponse = service.users().threads().list(USER).execute();
List<Thread> threads = threadsResponse.getThreads();
// Print ID of each Thread.
for (Thread thread : threads) {
System.out.println("Thread ID: " + thread.getId());
}
}
}
I replaced the reference to CLIENT_SECRET_PATH with:
new BufferedReader(new InputStreamReader(GmailApiQuickstart.class.getResourceAsStream(CLIENT_SECRET_PATH)))
for no other reason than to try something different. It does work and reads the file correctly.
Any ideas?
Answer
Right, after some more research (asking a colleague/genius), I found the problem. Basically the GoogleClientSecrets object was not being properly bound with the information from my client_secrets.json file. This meant that during authentication, objects were null resulting in the IllegalArgumentException.
So the original file which looked like this:
{
"private_key_id": "zzz",
"private_key": "-----BEGIN PRIVATE KEY-----\nxyz\n-----END PRIVATE KEY-----\n",
"client_email": "[email protected]",
"client_id": "1wdfghyjmp.apps.googleusercontent.com",
"type": "service_account"
}
was edited to look like this:
{
"web" : {
"private_key_id": "zzz",
"private_key": "-----BEGIN PRIVATE KEY-----\nxyz\n-----END PRIVATE KEY-----\n",
"client_email": "[email protected]",
"client_id": "1wdfghyjmp.apps.googleusercontent.com",
"type": "service_account"
}
}
This allowed me to progress through the code with authentication.
Hope this helps.