流动态资源出错。 将p：graphicImage与Primefaces一起使用

Question

I'm trying to dynamically display an image in primefaces using the p:graphicImage tag as follows:

<p:graphicImage value="#{submissionBean.contestImage}">
    <f:param name="imageName"
        value="#{contestBean.createContest.submissions[0].fileName}" />
</p:graphicImage>`

The managed bean is as follows:

@ManagedProperty("#{param.imageName}")
private String imageName;

public String getImageName()
{
    return imageName;
}

public void setImageName(String imageName)
{
    this.imageName = imageName;
}

private StreamedContent contestImage;

public StreamedContent getContestImage()
{
    FacesContext context = FacesContext.getCurrentInstance();
    if (imageName == null)
        imageName = Constants.SUBMISSION_FILE_DIR + "/" + "sacxzx_asdsdaas_icon.png";
    if (context.getRenderResponse())
    {
        // So, we're rendering the view. Return a stub StreamedContent so
        // that it will generate right URL.
        return new DefaultStreamedContent();
    }
    else
    {

        return new DefaultStreamedContent(this.getClass().getResourceAsStream(Constants.SUBMISSION_FILE_DIR + "/" + imageName));
    }
}

I'm always getting the error of "SEVERE: Error in streaming dynamic resource."

Checking the URL for the image seems just fine:

http://localhost:8080/mashup/javax.faces.resource/dynamiccontent.xhtml?ln=primefaces&pfdrid=pfdrid_4290aa0c-8eef-45ea-a281-638e460e33bf&imageName=sacxzx_asdsdaas_icon.png

Any idea why this is?

Thanks!

Answer 1

Should be SessionScoped . As method getContestImage() is called multiple times during page processing, it is better to create the stream only once.