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);
Related
I use vertica flex table to load json to vertica without defining the tables, and I got problems with my loading time.
I connect to my vertica with jdbc drive and then use this code..
String copyQuery = "COPY schema.tablename FROM STDIN PARSER fjsonparser()";
VerticaCopyStream vstream = new VerticaCopyStream((VerticaConnection)conn, copyQuery);
InputStream input;
vstream.start();
for(JsonNode json : jsonList){
input = new ByteArrayInputStream(json.toString().getBytes());
vstream.addStream(input);
input.close();
}
vstream.execute();
vstream.finish();
The command "vstream.execute()" takes 12 seconds for 5000 jsons but when I use COPY command from file it runs for less then a second.
Your problem is not with the VerticaCopyStream , the problem is with regard to the different parsers you used , you need to compare apple to apple , JSON parser should be more slower the simple CSV parser .
COPY FROM STDIN and COPY LOCAL stream data from the client. Running it on the server with just a COPY (no LOCAL or STDIN) will be a direct load straight from the vertica daemon with no network latency (assuming it is on local disk and not a NAS).
In addition, your method of reinstantiating the ByteArrayInputStream... wouldn't it be better to turn your jsonList into an InputStream and pass just that in instead of creating an input stream for every item?
if you run the samr insert by useing vsql it solve the problem
The docs mention that it is possible to retrieve a range of a document using gridFS. However I haven't found any more details about this. I would like to obtain a range of a file using the java driver for a grails app to support audio streaming. Do I need to get and assemble the packages manually in that case or is there any better way?
You can skip over the part of the file not needed and read only what you need from there.
GridFSDBFile file = files.findOne("file");
InputStream inputStream = file.getInputStream();
long actuallySkipped = inputStream.skip(numberOfBytesToSkip);
// read from here...
Hope this helps.
I would like to know if is possible get the image via POST method with a HTTP server implemented in Java (With a simple input file form). I already implemented the Java server but I can only get text files via POST method it's because that the my application only copies the file content to another empty file creating the same file with the same characteristics. This does not work with image file or other files, this can only work with text file.
Anyone know how to implement it with images?
Some coordinates would be of great help!
Thanks in advance!
As far as i know you should create something like it:
Server-side: If you use a servlet that receive data in post you have to get the outputStream from the response. Once you have it it is done because you write the data image on the stream.
For example let's suppose your image is a file stored in the server you could do:
response.setContentLength((int) fileSize);
byte b[] = new byte[1024];
while ( fOutStream.read(b) != -1)
response.getOutputStream().write(b);
fOutStream.close() ;
Where the fOutStream is the source stream (your image).
I'm hoping the answer to this question is quite simple, but I can't get it working after looking at the Azure Java API documentation.
I am trying to create an empty CloudBlockBlob, which will have blocks uploaded to it at a later point. I have successfully uploaded blocks before, when the blob is created upon the first block being uploaded, but I can't seem to get anything other than ("the specified blob does not exist") when I try to create a new blob without any data and then access it. I require this because in my service, a call is first made to create the new blob in Azure, and then later calls are used to upload blocks (at which point a check is made to see if the blob exists). Is it possible to create an empty blob in Azure, and upload data to it later? What have I missed?
I've not worked with Java SDK so I may be wrong but I tried creating an empty blob using C# code (storage client library 2.0) and if I upload an empty input stream an empty blob with zero byte size is created. I did something like the following:
CloudBlockBlob emptyBlob = blobContainer.GetBlockBlobReference("emptyblob.txt");
using (MemoryStream ms = new MemoryStream())
{
emptyBlob.UploadFromStream(ms);//Empty memory stream. Will create an empty blob.
}
I did look at Azure SDK for Java source code on Github here: https://github.com/WindowsAzure/azure-sdk-for-java/blob/master/microsoft-azure-api/src/main/java/com/microsoft/windowsazure/services/blob/client/CloudBlockBlob.java and found this "upload" function where you can specify an input stream. Try it out and see if it works for you.
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");