retrieve multimedia content from tridion using DD4T with java

Question

I am trying to retrieve multimedia content from Tridion using DD4T with Java. Can anyone let me know how this can be done?

I am using below syntax to create generic component and then trying to retrieve the image from Tridion component:

GenericComponent comp = (GenericComponent) request.getAttribute(Constants.COMPONENT_KEY);
comp.getMultimedia().getURL();

Not sure how can I retrieve this image.

Answer 1

You can use LinkResolver which is available in org.dd4t.core.resolvers.LinkResolver. Also make sure that in your dd4t template you have set the depth of link to the level which you have used in your schema. The following is a simple code which will retrieve only a single component. If you are having a collection of components then you will have to use a for-each loop and modify the code accordingly.

<%
LinkResolver linkResolver = (LinkResolver) ApplicationContextProvider.getBean("LinkResolver");
GenericComponent linkedComp=(GenericComponent)comp.getContent().get("imageFieldName").getValues().get(0);
String href = linkResolver.resolve(linkedComp);
%>
<img src=" <%=href %>" alt="">

Answer 2

You are not providing enough information in your question. And from the information you do provide, I think you are on the wrong path.

If you are on the server and want to retrieve Binary content, then you need to call the DD4T BinaryFactory and pass in the URL or TCMURI of the binary.

This is usually done in the BinaryController where you have the Binary URL. Sample code below:

@RequestMapping(method = {RequestMethod.GET, RequestMethod.HEAD})
public void getBinary(final HttpServletRequest request, final HttpServletResponse response) {
    String binaryPath = getBinaryPath(request);
    int publicationId = publicationResolver.getPublicationId();
    Binary binary = binaryFactory.getBinaryByURL(binaryPath, publicationId);
...
}

Then comes the delivery part, where you need to fill the Response object with the binary content and let it go back to the browser.

Naturally you would need caching to be done here, as you don't want to hit your BinaryProvider for each request. Some of the caching is done in the BinaryFactory, but you might want to implement some additional yourself.

Next, you will need to handle cache headers in request/response (if-modified-since, last-modified).

Finally, you will need error handling for corner cases (DB down, binary not published, exceptions from provider tier, etc).