我正在努力创建一个应用程序,使用 Java API 将苍蝇从本地机器上传到谷歌云存储。但我面临的问题是 API 不允许我上传超过 32 Mb 的文件,而我要上传的文件超过 100 Mb 或者可能是 200 Mb。 我非常感谢这方面的帮助,并且想知道将文件上传到 Google Cloud Storage 的最佳做法或 API 是什么。
我正在使用以下代码。
上传文件Servlet.java
import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.nio.channels.Channels;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.fileupload.FileItemIterator;
import org.apache.commons.fileupload.FileItemStream;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import com.google.appengine.api.blobstore.BlobKey;
import com.google.appengine.api.users.User;
import com.google.appengine.api.users.UserService;
import com.google.appengine.api.users.UserServiceFactory;
import com.google.appengine.tools.cloudstorage.GcsFileOptions;
import com.google.appengine.tools.cloudstorage.GcsFilename;
import com.google.appengine.tools.cloudstorage.GcsOutputChannel;
import com.google.appengine.tools.cloudstorage.GcsService;
import com.google.appengine.tools.cloudstorage.GcsServiceFactory;
import com.google.appengine.tools.cloudstorage.RetryParams;
import com.igt.service.StorageService;
public class UploadFileServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
private StorageService storage = new StorageService();
private static int BUFFER_SIZE = 1024 * 1024 * 10;
public static final String BUCKET_NAME = "my-bucket-test";
private final GcsService gcsService = GcsServiceFactory.createGcsService(RetryParams.getDefaultInstance());
@Override
public void doPost(HttpServletRequest req, HttpServletResponse resp)
throws IOException {
UserService userService = UserServiceFactory.getUserService();
User user = userService.getCurrentUser();
if (user != null) {
resp.setContentType("text/plain");
resp.getWriter().println("Now see here your file content, that you have uploaded on storage..");
ServletFileUpload upload = new ServletFileUpload();
FileItemIterator iter;
try {
iter = upload.getItemIterator(req);
while (iter.hasNext()) {
FileItemStream item = iter.next();
String fileName = item.getName();
String mime = item.getContentType();
GcsFileOptions options = new GcsFileOptions.Builder()
.acl("public_read")
.mimeType(mime)
.build();
GcsFilename filename = new GcsFilename(BUCKET_NAME, fileName);
GcsOutputChannel outputChannel = gcsService.createOrReplace(filename, options);
// Writing the file to input stream
InputStream is = new BufferedInputStream(item.openStream());
// Copying InputStream to GcsOutputChannel
try {
copy(is, Channels.newOutputStream(outputChannel));
} finally {
outputChannel.close();
is.close();
}
resp.getWriter().println("File uploading done");
System.out.println("File uploading done");
// resp.getWriter().println("READ:" +
// storage.readTextFileOnly(fileName));
BlobKey key = storage.getBlobkey(fileName);
if (key != null) {
resp.sendRedirect("/serve?blob-key=" + key.getKeyString());
} else {
resp.sendRedirect("/login");
}
resp.sendRedirect("/login");
}
} catch (Exception e) {
e.printStackTrace(resp.getWriter());
System.out.println("Exception::" + e.getMessage());
e.printStackTrace();
}
} else {
resp.sendRedirect(userService.createLoginURL(req.getRequestURI()));
}
}
private void copy(InputStream input, OutputStream output) throws IOException {
byte[] buffer = new byte[BUFFER_SIZE];
int bytesRead = input.read(buffer);
while (bytesRead != -1) {
output.write(buffer, 0, bytesRead);
bytesRead = input.read(buffer);
}
}
存储服务.java
import java.io.BufferedOutputStream;
import java.nio.channels.Channels;
import java.util.logging.Logger;
import com.google.appengine.api.blobstore.BlobKey;
import com.google.appengine.api.blobstore.BlobstoreService;
import com.google.appengine.api.blobstore.BlobstoreServiceFactory;
import com.google.appengine.api.files.AppEngineFile;
import com.google.appengine.api.files.FileService;
import com.google.appengine.api.files.FileServiceFactory;
import com.google.appengine.api.files.FileWriteChannel;
import com.google.appengine.api.files.GSFileOptions.GSFileOptionsBuilder;
@SuppressWarnings("deprecation")
public class StorageService {
private static final Logger log = Logger.getLogger(StorageService.class.getName());
private BlobstoreService blobstoreService = BlobstoreServiceFactory.getBlobstoreService();
public BlobKey getBlobkey(String filename) {
BlobKey bk = blobstoreService.createGsBlobKey("/gs/sample-bucket/" + filename);
return bk;
}
}
登录.jsp
<form action="/upload" method="post" enctype="multipart/form-data">
<div><input name = "file" type="file" value="Upload" /></div>
<div><input type="submit" value="Upload File" /></div>
</form>
最佳答案
来自用户的单个 AppEngine 连接不能传输超过 32 MB。相反,您应该让您的用户将文件直接上传到 Google Cloud Storage。 Google Cloud Storage 支持标准的 HTML 表单上传。此处提供了完整的文档:https://developers.google.com/storage/docs/reference-methods#postobject
让用户的页面提交一个表单帖子,其中包含指定存储桶和对象名称的所有适当的表单字段。存储桶需要是公开可写的,或者您需要包含适当的签名字段。
将“success_action_redirect”字段设置为 AppEngine URL。上传成功完成后,浏览器将重定向到此 URL。
关于google-app-engine - 如何使用 Java API 将超过 32Mb 的文件上传到谷歌云存储,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/19364790/