如何使用< p:media>绑定动态内容?

问题描述

我使用<p:media>显示静态PDF内容.

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

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

如何更改它以显示动态内容?

How can I change it to display dynamic content?

推荐答案

与<p:graphicImage>中一样，value属性可以指向返回StreamedContent的bean属性.出于以下原因，这仅需要一种特殊的getter方法，有关将<p:graphicImage>与数据库中的动态资源一起使用的以下答案中对此进行了详细说明:.

Like as in <p:graphicImage>, the value attribute can point to a bean property returning StreamedContent. This only requires a special getter method for the reasons which is explained in detail in the following answer on using <p:graphicImage> with a dynamic resource from a database: Display dynamic image from database with p:graphicImage and StreamedContent.

在您的特定示例中，它看起来像这样:

In your particular example, it would look like this:

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

使用

@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()));
        }
    }

}

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