WS Download operation with MTOM

Question

I want to stream directly from an Oracle database blobs files via WS with MTOM directly to the WS client.

I thought I found a way which is described here:

http://www.java.net/forum/topic/glassfish/metro-and-jaxb/mtom-best-practices

but after i took a look on InputStreamDataSource and javax.mail.util.ByteArrayDataSource i realized that they acutal hava a byte[] of the 'document' in memory meaning the streaming ideea is in vain, cause what i try to avoid is to have multiple docs in the same time fully in memory.

So how can I stream from DB via WS and MTOM to a WS client ?

Any idea ?

Thanks

Cris

Answer 1

I tried experimenting and finally i had some positive results.

In order to stream from DB directly to clients browser the above things are valid but the InputStreamDataSource should be like this:

public class InputStreamDataSource implements DataSource {
    private InputStream inputStream;

    public InputStreamDataSource(InputStream inputStream) {
        this.inputStream = inputStream;
    }

    public InputStream getInputStream() throws IOException {
        return inputStream;
    }

    public OutputStream getOutputStream() throws IOException {
        throw new UnsupportedOperationException("Not implemented");
    }

    public String getContentType() {
        return "*/*";
    }

    public String getName() {
        return "InputStreamDataSource";
    }
}

What I was affraid is that once I closed the input stream myself... the ws client did not received the binary content...

Than i check and actually the DataHandler creates a new thread and closes the input stream

I was able to stream 500MB from DB to client fast and with low memory footprint !