ServletContext getResource not working

Question

I'm trying to use ServletContext.getResource to retrieve a java.net.url reference to an image file (which I will then include in a PDF library using iText).
When I use ServletContext.getRealPath("picture.jpg"), I get back a string URL. However, getResource always returns null.

Example 1:

String picture = ServletContext.getRealPath("picture.jpg");
// picture contains a non-null String with the correct path
URL pictureURL = ServletContext.getResource(picture);
// pictureURL is always null

Example 2:

URL pictureURL = ServletContext.getResource("picture.jpg");
// pictureURL is always null

So what is the correct way to build a java.net.URL object pointing to a file in my webapps/ folder? Why does getRealPath work but not getResource?

In case it helps at all, here is my folder structure

webapps -> mySite -> picture.jpg

Does my picture need to be stored in either WEB-INF or WEB-INF/classes to be read by getResource?

Answer 1

Returns a URL to the resource that is mapped to a specified path. The path must begin with a "/" and is interpreted as relative to the current context root.

So you must provide the context-relative full path. For example:

URL pictureURL = servletContext.getResource("/images/picture.jpg");

(note the lower-cased servletContext variable)

Answer 2

getRealPath() provides the operating specific absolute path of a resource, while getResource() accepts a path relative to the context directory, and the parameter must begin with a "/". Try ServletContext.getResource ("/picture.jpg") instead.

Doc: getResource