使用gae将数据存储到谷歌云存储中用于java

Question

我正在尝试将数据从应用引擎应用存储到谷歌云存储。

如果我这样做本地代码运行良好，但我没有看到任何数据存储。

如果我将应用程序上传到应用程序引擎，则运行代码时出现空指针异常： AppEngineFile writableFile = fileService.createNewGSFile（optionsBuilder.build（））;

使用的完整代码IM是

 // Get the file service 
     FileService fileService = FileServiceFactory.getFileService(); 

     /** 
     * Set up properties of your new object 
     * After finalizing objects, they are accessible 
     * through Cloud Storage with the URL: 
     * http://commondatastorage.googleapis.com/my_bucket/my_object 
     */ 
     GSFileOptionsBuilder optionsBuilder = new GSFileOptionsBuilder() 
      .setBucket("blood") 
      .setKey("1234567") 
      .setAcl("public-read") 
      .setMimeType("text/html");//.setUserMetadata("date-created", "092011", "owner", "Jon"); 


     // Create your object 
     AppEngineFile writableFile = fileService.createNewGSFile(optionsBuilder.build()); 

     // Open a channel for writing 
     boolean lockForWrite = true; // Do you want to exclusively lock this object? 
     FileWriteChannel writeChannel = fileService.openWriteChannel(writableFile, lockForWrite); 
     // For this example, we write to the object using the PrintWriter 
     PrintWriter out = new PrintWriter(Channels.newWriter(writeChannel, "UTF8")); 
     out.println("The woods are lovely and deep."); 
     out.println("But I have promises too keep."); 

     // Close the object without finalizing. 
     out.close(); 

     // Finalize the object 
     writeChannel.closeFinally(); 
     System.out.println("Completed writing to google storage"); 

Answer 1

所以问题在于应用程序引擎未被授权读取/写入在云存储中创建的存储桶。

Answer 2

当使用开发服务，并与谷歌存储文件服务，它实际上并没有写信给你的谷歌存储桶，但到本地文件系统 - 你期待它写入Google Storage？

对于空指针异常，需要查看堆栈跟踪以尝试缩小发生了什么问题。