GoogleCalendarAPISampleJWT.java

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.security.GeneralSecurityException;
import java.security.PrivateKey;
import java.util.Arrays;

import com.google.api.client.googleapis.auth.oauth2.GoogleCredential;
import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.json.JsonFactory;
import com.google.api.client.json.jackson2.JacksonFactory;
import com.google.api.client.util.SecurityUtils;
import com.google.api.services.calendar.Calendar;
import com.google.api.services.calendar.model.CalendarList;
import com.google.api.services.calendar.model.CalendarListEntry;

public class GoogleCalendarAPISampleJWT {
	public static void main(String[] args) {
		//System.setProperty("https.proxyHost", "127.0.0.1");
		//System.setProperty("https.proxyPort", "8888");

		try {
			HttpTransport httpTransport = GoogleNetHttpTransport.newTrustedTransport();
			
			JsonFactory jacksonFactory = JacksonFactory.getDefaultInstance();

			InputStream in = new FileInputStream(new File("resources/privatekey.p12"));
		      PrivateKey privateKey = SecurityUtils.loadPrivateKeyFromKeyStore(SecurityUtils.getPkcs12KeyStore(), in, "notasecret", "privatekey", "notasecret");
		      GoogleCredential credential = new GoogleCredential.Builder()
		        .setTransport(httpTransport)
		        .setJsonFactory(jacksonFactory)
		        .setServiceAccountId("google-calendar-sample@xxxxx-yyyyy-123456.iam.gserviceaccount.com")
		        .setServiceAccountScopes(Arrays.asList("https://www.googleapis.com/auth/calendar"))
		        .setServiceAccountPrivateKey(privateKey)
		        .setServiceAccountUser("foo@example.com")
		      .build();

			Calendar service = new com.google.api.services.calendar.Calendar.Builder(
			          httpTransport, jacksonFactory, credential).setApplicationName("GoogleCalendarAPISampleJWT").build();

			System.out.println("Your calendars:");
			System.out.println();
			CalendarList feed = service.calendarList().list().execute();
			for (CalendarListEntry entry : feed.getItems()) {
			    System.out.println();
			    System.out.println("-----------------------------------------------");
			    System.out.println("ID: " + entry.getId());
			    System.out.println("Summary: " + entry.getSummary());
			    if (entry.getDescription() != null) {
			      System.out.println("Description: " + entry.getDescription());
			    }
			}

		} catch (GeneralSecurityException e) {
			System.err.println(e.getMessage());
		} catch (IOException e) {
			System.err.println(e.getMessage());
		}
		System.exit(1);
	}
}

GoogleCalendarAppSkeleton

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.security.GeneralSecurityException;
import java.security.PrivateKey;
import java.util.Arrays;

import com.google.api.client.googleapis.auth.oauth2.GoogleCredential;
import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.json.JsonFactory;
import com.google.api.client.json.jackson2.JacksonFactory;
import com.google.api.client.util.SecurityUtils;
import com.google.api.services.calendar.Calendar;

public class GoogleCalendarAppSkeleton {
	public static void main(String[] args) {
		//System.setProperty("https.proxyHost", "127.0.0.1");
		//System.setProperty("https.proxyPort", "8888");

		try {
			HttpTransport httpTransport = GoogleNetHttpTransport.newTrustedTransport();
			
			JsonFactory jacksonFactory = JacksonFactory.getDefaultInstance();

			InputStream in = new FileInputStream(new File("resources/privatekey.p12"));
		      PrivateKey privateKey = SecurityUtils.loadPrivateKeyFromKeyStore(SecurityUtils.getPkcs12KeyStore(), in, "notasecret", "privatekey", "notasecret");
		      GoogleCredential credential = new GoogleCredential.Builder()
		        .setTransport(httpTransport)
		        .setJsonFactory(jacksonFactory)
		        .setServiceAccountId("google-calendar-sample@xxxxx-yyyyy-123456.iam.gserviceaccount.com")
		        .setServiceAccountScopes(Arrays.asList("https://www.googleapis.com/auth/calendar"))
		        .setServiceAccountPrivateKey(privateKey)
		        .setServiceAccountUser("foo@example.com")
		      .build();

			Calendar service = new com.google.api.services.calendar.Calendar.Builder(
			          httpTransport, jacksonFactory, credential).setApplicationName("GoogleCalendarAPISampleJWT").build();

			// write your process

		} catch (GeneralSecurityException e) {
			System.err.println(e.getMessage());
		} catch (IOException e) {
			System.err.println(e.getMessage());
		}
		System.exit(1);
	}
}