影像不必要地显示在 <p:graphicImage> 事件虽然没有提供资源目录中的图像名称

Question

I have stored some images under the webroot\\resources\\fileUpload\\product_image\\thumb directory so that these images can be displayed on <p:graphicImage> as follows.

<p:graphicImage library="fileUpload" 
                name="product_image/thumb/13850470212653732655006325945389_4921.jpg" 
                alt="Whatever the product name is."/>

If the image name ie 13850470212653732655006325945389_4921.jpg is not given then, the image should not be displayed but it displays an image from the given URL.

<p:graphicImage library="fileUpload" 
                name="product_image/thumb/" 
                alt="Whatever the product name is."/>

The image URL on the web browser appears as follows.

/webroot/javax.faces.resource/product_image/thumb/.jsf?ln=fileUpload&v=13850470212653732655006325945389_4921

How does it pick up an image?

Answer 1

If the resource filename matches \\d+(_\\d+) , then it's recognized as a versioned resource. This is a rarely used feature ( resource library versioning is more common). Concretely, you can have such a structure:

WebContent
 |-- resources
 |    `-- js
 |         `-- script.js
 |              |-- 1_0.js
 |              |-- 1_1.js
 |              `-- 1_2.js
 :

(yes, script.js is here the folder name)

And when you declare it as follows:

<h:outputScript name="js/script.js" />

then automatically the latest one, the 1_2.js , will be served as per the following generated HTML output, provided a context path of /context and a JSF mapping of *.xhtml :

<script type="text/javascript" src="/context/javax.faces.resource/scripts/script.js.xhtml?v=1_2"></script>

This all is specified in chapter 2.6.1.3 of JSF specification .

You've there however a bit unfortunate corner case of using an extensionless folder with a trailing slash as resource name, which should IMO have failed, but it apparently is also accepted by Mojarra.

If you'd like to avoid this behavior, you need to use a different pattern as file name. Eg use - instead of _ , or use _ as prefix or suffix, or bring in at least one alphabetic character.