CODEWITHSUNDEEP
javastreamvaadinvaadin7
user1053031
user1053031

Reputation: 747

Save Vaadin7 StreamResource to file

I have an object of StreamResource class w/ some needed content in it. I'm sure this content is valid and i need to save it locally for the further processing. Here is the code snippet:

OutputStream os = new FileOutputStream(filePath, false);

byte[] buffer = new byte[1024];
int bytesRead;
//read from is to buffer
try {
    while(true)
    {
         bytesRead = resource.getStream().getStream().read(buffer);
         if(bytesRead == -1)
             break;

         os.write(buffer, 0, bytesRead);
         resource.getStream().getStream().skip(bytesRead);
    }
    os.flush();
    os.close();
} catch (IOException e) {
    e.printStackTrace();
}

And here i join the endless loop. Break is never ocured and file in the needed location becomes huge as it should actually. Under debugger i see that read() operation returns only the 1st chunk of bytes in each iteration even w/ skip() call after os.write.

How should i read the content from the stream?

Thanks.

Upvotes: 0

Views: 959

Answers (1)

Steffen Harbich
Steffen Harbich

Reputation: 2749

According to the source code of StreamResource a new DownloadStream is created on each call. You should call it only once like in the following snippet:

OutputStream os = new FileOutputStream(filePath, false);

byte[] buffer = new byte[1024];
int bytesRead;
//read from is to buffer
try {
    DownloadStream stream = resource.getStream();
    while(true)
    {
         bytesRead = stream.getStream().read(buffer);
         if(bytesRead == -1)
             break;

         os.write(buffer, 0, bytesRead);
    }
    os.flush();
    os.close();
} catch (IOException e) {
    e.printStackTrace();
}

That way the stream will not be read from the beginning on every iteration. However, I still don't get why you use the indirection over StreamResource because I guess you create that object before.

Upvotes: 1

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