CODEWITHSUNDEEP
javajersey
carlspring
carlspring

Reputation: 32627

How to use Jersey's Response.ok(inputStream) method properly

I am trying to optimize the following code which is used to produce a stream containing random data of a given length that is streamed from the server to the client:

@GET
@Path("/foo/....")
public Response download(...)
        throws IOException
{
    ...
    ByteArrayOutputStream baos = new ByteArrayOutputStream();

    // This method writes some random bytes to a stream.
    generateRandomData(baos, resource.length());

    System.out.println("Generated stream with " +
                       baos.toByteArray().length +
                       " bytes.");

    InputStream is = new ByteArrayInputStream(baos.toByteArray());

    return Response.ok(is).build();
}

The code above look ridiculous as it won't work for large data, I know, but I haven't found a better method for writing to the stream of the response. Could somebody please show me the proper way of doing it?

Many thanks in advance!

Upvotes: 3

Views: 5725

Answers (1)

gma
gma

Reputation: 2563

Create your own InputStream implementation defining read method to return random data : 

public class RandomInputStream
        extends InputStream
{

    private long count;

    private long length;

    private Random random = new Random();


    public RandomInputStream(long length)
    {
        super();
        this.length = length;
    }

    @Override
    public int read()
            throws IOException
    {
        if (count >= length)
        {
            return -1;
        }

        count++;

        return random.nextInt();
    }

    public long getCount()
    {
        return count;
    }

    public void setCount(long count)
    {
        this.count = count;
    }

    public long getLength()
    {
        return length;
    }

    public void setLength(long length)
    {
        this.length = length;
    }

}

Upvotes: 2

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