Save output to a stream Leave feedback

By default, GroupDocs.Viewer saves output results to the local disk. Also, it can provide results as a stream.

To provide output results as a stream, use one of the following interfaces:

• FileStreamFactory defines methods to instantiate and release the output file streams.
• PageStreamFactory defines methods to instantiate and release the output page streams.
• ResourceStreamFactory defines the methods to create resource URLs, instantiate, and release output HTML resource streams.

Use these interface as follows:

• When rendering to PDF, implement the FileStreamFactory interface and pass the implementation to the PdfViewOptions constructor.
• When rendering to JPG/PNG or HTML with embedded resources, implement the PageStreamFactory interface and pass the implementation to the JpgViewOptions/PngViewOptions constructor or to the HtmlViewOptions forEmbeddedResources factory method.
• When rendering into HTML with external resources, implement the PageStreamFactory and ResourceStreamFactory interfaces and pass the implementation to the JpgViewOptions/PngViewOptions constructor or to the HtmlViewOptions forExternalResources factory method.

The following code snippet shows how to render to HTML with embedded resources and to provide the output result as a stream. To do this, it implements the PageStreamFactory interface only.

import com.groupdocs.viewer.Viewer;
import com.groupdocs.viewer.interfaces.PageStreamFactory;
import com.groupdocs.viewer.options.HtmlViewOptions;
import com.groupdocs.viewer.options.ViewOptions;
// ...

final List<ByteArrayOutputStream> pages = new ArrayList<>();

try (Viewer viewer = new Viewer("sample.docx")) {

    PageStreamFactory pageStreamFactory = new PageStreamFactory() {

        @Override
        public OutputStream createPageStream(int pageNumber) {
            ByteArrayOutputStream pageStream = new ByteArrayOutputStream();

            pages.add(pageStream);

            return pageStream;
        }

        @Override
        public void closePageStream(int pageNumber, OutputStream outputStream) {
            //Do not release page stream as we'll need to keep the stream open
        }
    };

    ViewOptions viewOptions = HtmlViewOptions.forEmbeddedResources(pageStreamFactory);

    viewer.view(viewOptions);
}