我使用下面的代码将内容写入我的文件google云端存储。
FileService fileService = FileServiceFactory.getFileService();
GSFileOptionsBuilder optionsBuilder = new GSFileOptionsBuilder()
.setBucket(BUCKETNAME)
.setKey(FILENAME)
.setMimeType("text/html")
.setAcl("public_read")
.addUserMetadata("myfield1", "my field value");
AppEngineFile writableFile =
fileService.createNewGSFile(optionsBuilder.build());
// Open a channel to write to it
boolean lock = false;
FileWriteChannel writeChannel =
fileService.openWriteChannel(writableFile, lock);
// Different standard Java ways of writing to the channel
// are possible. Here we use a PrintWriter:
PrintWriter out = new PrintWriter(Channels.newWriter(writeChannel, "UTF8"));
out.println("The woods are lovely dark and deep.");
out.println("But I have promises to keep.");
// Close without finalizing and save the file path for writing later
out.close();
String path = writableFile.getFullPath();
// Write more to the file in a separate request:
writableFile = new AppEngineFile(path);
// Lock the file because we intend to finalize it and
// no one else should be able to edit it
lock = true;
writeChannel = fileService.openWriteChannel(writableFile, lock);
// This time we write to the channel directly
writeChannel.write(ByteBuffer.wrap
("And miles to go before I sleep.".getBytes()));
// Now finalize
writeChannel.closeFinally();
resp.getWriter().println("Done writing...");
// At this point, the file is visible in App Engine as:
// "/gs/BUCKETNAME/FILENAME"
// and to anybody on the Internet through Cloud Storage as:
// (http://storage.googleapis.com/BUCKETNAME/FILENAME)
// We can now read the file through the API:
String filename = "/gs/" + BUCKETNAME + "/" + FILENAME;
AppEngineFile readableFile = new AppEngineFile(filename);
FileReadChannel readChannel =
fileService.openReadChannel(readableFile, false);
// Again, different standard Java ways of reading from the channel.
BufferedReader reader =
new BufferedReader(Channels.newReader(readChannel, "UTF8"));
String line = reader.readLine();
resp.getWriter().println("READ:" + line);
// line = "The woods are lovely, dark, and deep."
readChannel.close();
它似乎在写,然后阅读,但是当我检查云存储区域(使用firefox)时,该文件尚未被编辑。有什么想法吗?
答案 0 :(得分:2)
这是在生产或开发环境中吗?
当您使用开发服务器时,对Google存储的写入是模拟的,不会写入真正的存储桶。
答案 1 :(得分:1)
可能有两个问题。
您可能忘记向存储桶添加权限。检查https://developers.google.com/appengine/docs/java/googlestorage/overview#Prerequisites如何操作。
您正在尝试更新该文件。在writeChannel.closeFinally()之后,该文件变为只读。您无法更改/更新/附加到它。