Question

根据Google Calendar API Quickstart for java（第3步），我们可以使用

InputStream in = CalendarQuickstart.class.getResourceAsStream(CREDENTIALS_FILE_PATH); 解析凭据.json。

但是，它仅在Android Studio外部运行文件时有效。在Android Studio中运行CalendarQuickStart.java主方法（不运行应用程序）将导致nullpointer异常。

我发现使用getAsset()可能是解决问题的一种方法

InputStream in = context.getAssets().open(CREDENTIALS_FILE_PATH);。设置资产文件夹很容易，但要使context正常工作是非常棘手的。

这是我的文件路径：

这是我的代码：

 import android.content.Context;
 import android.support.v7.app.AppCompatActivity;

 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.DateTime;
 import com.google.api.client.util.store.FileDataStoreFactory;
 import com.google.api.services.calendar.Calendar;
 import com.google.api.services.calendar.CalendarScopes;
 import com.google.api.services.calendar.model.Event;
 import com.google.api.services.calendar.model.Events;

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

 public class CalendarQuickstart extends AppCompatActivity {
     private static final String APPLICATION_NAME = "Google Calendar API Java Quickstart";
     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(CalendarScopes.CALENDAR_READONLY);
     private static final String CREDENTIALS_FILE_PATH = "/credentials.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 = CalendarQuickstart.class.getResourceAsStream(CREDENTIALS_FILE_PATH);
         //InputStream in = context.getAssets().open(CREDENTIALS_FILE_PATH);
         System.out.println(in);
         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 {
         // Build a new authorized API client service.
         final NetHttpTransport HTTP_TRANSPORT = GoogleNetHttpTransport.newTrustedTransport();
         Calendar service = new Calendar.Builder(HTTP_TRANSPORT, JSON_FACTORY, getCredentials(HTTP_TRANSPORT))
                 .setApplicationName(APPLICATION_NAME)
                 .build();

         // List the next 20 events from the primary calendar.
         DateTime now = new DateTime(System.currentTimeMillis());
         Events events = service.events().list("primary")
                 .setMaxResults(20)
                 .setTimeMin(now)
                 .setOrderBy("startTime")
                 .setSingleEvents(true)
                 .execute();
         List<Event> items = events.getItems();
         if (items.isEmpty()) {
             System.out.println("No upcoming events found.");
         } else {
             System.out.println("Upcoming events");
             for (Event event : items) {
                 DateTime start = event.getStart().getDateTime();
                 if (start == null) {
                     start = event.getStart().getDate();
                 }
                 System.out.printf("%s (%s)\n", event.getSummary(), start);
             }
         }
     }
 }

在Android Studio中运行CalendarQuickstart.java的更好方法是什么？

Android Studio中的getResourceAsStream（credentials.json）时为Nullpointer

0 个答案: