[英]How to get uploaded excel file from blobstore and how to assign that file to FileInputStream
I am working on project using GWT Java. 我正在使用GWT Java进行项目。 I uploaded excel file into blobstore in google app engine. 我将Excel文件上传到了Google App Engine中的Blobstore中。 I want to read excel file from blobstore. 我想从blobstore读取Excel文件。 So I have to assign the that excel file from blobstore to FileInputStream. 因此,我必须将excel文件从blobstore分配给FileInputStream。
Example: 例:
FileInputStream file = new FileInpuStream("what is path shall i provide here")
What are the possible ways to assign that excel file from blobstore to FileInputStream? 将Blobstore中的excel文件分配给FileInputStream的可能方法是什么? Any help? 有什么帮助吗?
Thanks in Advance 提前致谢
You can use the Apache POI to open the Excel File using your FileInputStream
with for example: 您可以使用Apache POI通过FileInputStream
打开Excel文件,例如:
XSSFWorkbook wb = new XSSFWorkbook(new FileInputStream(<whatever>));
and work with the POI API to modify the Excelsheet or get the cellinfos. 并与POI API一起修改Excelsheet或获取cellinfos。 More information to Apache POI: click here . 有关Apache POI的更多信息: 单击此处 。
Or to see a similar problem on SO: click here 或在SO上看到类似的问题: 单击此处
The Apache POI XSSFWorkbook
accepts either a File
or an InputStream
. Apache POI XSSFWorkbook
接受File
或InputStream
。 Assuming that you can access your Blob object via BlobstoreInputStream
instance, you can call: 假设您可以通过BlobstoreInputStream
实例访问Blob对象,则可以调用:
// BlobKey blobKey = initialize your blob key
XSSFWorkbook wb = new XSSFWorkbook(new BlobstoreInputStream(blobKey));
You can access the Blobstore
via: 您可以通过以下方式访问Blobstore
:
public class Upload extends HttpServlet {
private BlobstoreService blobstoreService = BlobstoreServiceFactory.getBlobstoreService();
@Override
public void doPost(HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException {
Map<String, List<BlobKey>> blobs = blobstoreService.getUploads(req);
List<BlobKey> blobKeys = blobs.get("myFile");
if (blobKeys != null && !blobKeys.isEmpty()) {
XSSFWorkbook wb = new XSSFWorkbook(new BlobstoreInputStream(blobKeys.get(0)));
}
}
}
Further reading: Blobstore Java API Overview 进一步阅读: Blobstore Java API概述
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