jsf - How to bind dynamic content using ?

Question

I use the <p:media> to display static PDF content.

<p:media value="/resource/test.pdf" 
         width="100%" height="300px" player="pdf">  
</p:media>

How can I change it to display dynamic content?

Answer 1

就像在中一样<p:graphicImage>，value属性可以指向返回的 bean 属性StreamedContent。这只需要一个特殊的 getter 方法，原因在以下关于使用<p:graphicImage>数据库中的动态资源的答案中有详细说明：使用 p:graphicImage 和 StreamedContent 显示来自数据库的动态图像。

在您的特定示例中，它看起来像这样：

<p:media value="#{mediaManager.stream}" width="100%" height="300px" player="pdf">
    <f:param name="id" value="#{bean.mediaId}" />
</p:media>

和

@ManagedBean
@ApplicationScoped
public class MediaManager {

    @EJB
    private MediaService service;

    public StreamedContent getStream() throws IOException {
        FacesContext context = FacesContext.getCurrentInstance();

        if (context.getCurrentPhaseId() == PhaseId.RENDER_RESPONSE) {
            // So, we're rendering the HTML. Return a stub StreamedContent so that it will generate right URL.
            return new DefaultStreamedContent();
        } else {
            // So, browser is requesting the media. Return a real StreamedContent with the media bytes.
            String id = context.getExternalContext().getRequestParameterMap().get("id");
            Media media = service.find(Long.valueOf(id));
            return new DefaultStreamedContent(new ByteArrayInputStream(media.getBytes()));
        }
    }

}