Develop Reference

Save pdf report on database using BIRT

So, I'm trying to save the pdf report in database using service methode. I saw that there's a way to specify the output of the generated report by calling : pdfOptions.setOutputStream(output). But how can I call my save methode this way?
I saw this post but i'm stack at the persist point
I apreciate any advice
PDFRenderOption pdfOptions = new PDFRenderOption(options);
pdfOptions.setOutputFormat(FORMAT_PDF);
pdfOptions.setOption(IPDFRenderOption.PAGE_OVERFLOW, IPDFRenderOption.OUTPUT_TO_MULTIPLE_PAGES);
pdfOptions.setOutputStream(response.getOutputStream());//opens report on browser
runAndRenderTask.setRenderOption(pdfOptions);

You are streaming the output directly to the client with
pdfOptions.setOutputStream(response.getOutputStream());//opens report on browser
If you do this, your output gets consumed and you'll not be able to save it to the database.
I would use a "tee" like approach, you know, with one input stream and two output streams.
You could write that yourself, our you just use something like the Apache TeeOutputStream.
This could look like this:
OutputStream blobOutputStream = ...; // for writing to the DB as BLOB.
OutputStream teeStream = TeeOutputStream(response.getOutputStream(), blobOutputStream);
pdfOptions.setOutputStream(teeStream);

How to update the content of a file in Google Drive?

I am trying to update the content of a Google Doc file with the content of another Google Doc file. The reason I don't use the copy method of the API is because that creates another file with another ID. My goal is to keep the current ID of the file. This is a code snippet which unfortunately does nothing:
com.google.api.services.drive.Drive.Files.Get getDraft = service.files().get(draftID);
File draft = driveManager.getFileBackoffExponential(getDraft);
com.google.api.services.drive.Drive.Files.Update updatePublished = service.files().update(publishedID, draft);
driveManager.updateFileBackoffExponential(updatePublished);
The two backoffExponential functions just launch the execute method on the object.
Googling around I found out that the update method offers another constructor:
public Update update(java.lang.String fileId, com.google.api.services.drive.model.File content, com.google.api.client.http.AbstractInputStreamContent mediaContent)
Thing is, I have no idea how to retrieve the mediaContent of a Google file such as a Google Doc.
The last resort could be a Google Apps Script but I'd rather avoid that since it's awfully slow and unreliable.
Thank you.
EDIT: I am using Drive API v3.

Try the Google Drive REST update.
Updates a file's metadata and/or content with patch semantics.
This method supports an /upload URI and accepts uploaded media with
the following characteristics:
Maximum file size: 5120GB Accepted Media MIME types: /*
To download a Google File in the format that's usable, you need to specify the mime-type. Since you're using Spreadsheets, you can try application/vnd.openxmlformats-officedocument.spreadsheetml.sheet. Link to Download files for more info.

Create Download Link But Source is Java String

I want to create a download link but the part I'm having trouble is that the source is a Java string. The String I have is a JSON data. I want people to be able to download that data.
I am using the Play! framework so I can pass the String data using the Scala template. But I'm not sure how to allow users to download the String and append the file types (.txt, .json) so that users actually download a file.
How do I go about to doing this?

I can't believe how simple the solution is. This was what did it for me. Basically take the string and convert it into an InputStream.
String data = "someBigOrSmallData";
InputStream dataStream = new ByteArrayInputStream(data.getBytes());
response().setHeader("Content-disposition","attachment; filename=anyFileName.txt");
return ok(dataStream);

Programmatically Downloading CSV Files with Java

Scenario: A website I use to research stock data has a link on the page to Export Data to Spreadsheet. The URL displayed when hovering over the export link is of the form http://www.stocksite.com/historical/export.php?symbol=C .
Question: Rather, that manually visiting the page for each stock I would like to automate the task. From Java, how can I programmatically call the site with a stock symbol and save the exported csv file? The URL and URLConnection class seem like the obvious place to start, but I'm unsure where to go from there.

All you need to do is to get the CSV in flavor of an InputStream.
InputStream input = new URL("http://example.com/file.csv").openStream();
Then you can feed it to any decent Java CSV parser API. Almost any of them take input in flavor of InputStream or Reader. If necessary, you can easily decorate InputStream as a Reader using InputStreamReader which you can then feed to the CSV parser.
Reader reader = new InputStreamReader(input, "UTF-8");

Get real file extension -Java code

I would like to determine real file extension for security reason.
How can I do that?

Supposing you really mean to get the true content type of a file (ie it's MIME type) you should refer to this excellent answer.
You can get the true content type of a file in Java using the following code:
File file = new File("filename.asgdsag");
InputStream is = new BufferedInputStream(new FileInputStream(file));
String mimeType = URLConnection.guessContentTypeFromStream(is);

There are a number of ways that you can do this, some more complicated (and more reliable) than others. The page I linked to discusses quite a few of these approaches.

Not sure exactly what you mean, but however you do this it is only going to work for the specific set of file formats which are known to you
you could exclude executables (are you talking windows here?) - there's some file header information here http://support.microsoft.com/kb/65122 - you could scan and block files which look like they have an exe header - is this getting close to what you mean when you say 'real file extension'?