Find a resource (.txt file) in war file which is d

问题:

I have a war file is packaged in ear and deployed. Here is the structure:

EAR
-WAR
--input.txt
--META-INF
--WEB-INF
---classes
(and so on)

I am trying to read input.txt from one of the classes (say abc.xyz.Myclass) in WEB-INF/classes folder. Here is what I tried:

this.getClass().getClassLoader().getResourceAsStream("../../input.txt");

and

Thread.currentThread().getContextClassLoader().getResourceAsStream("../../input.txt");

I tried several paths like "../input.txt" or "/input.txt" or just "input.txt" by attaching a debugger. But every time I am getting NULL as return value (means it is not able to find the file).

What is the correct way to access that file in war irrespective of whether war is deployed standalone or it is packed in ear? Please help.

回答1:

That is because input.txt is outside of the classpaths, one of which is typically WEB-INF/classes/, and you cannot access resources that is located outside the classpath using classloaders.

Alternatively, if the code can access the HttpServletRequest object:

    request.getServletContext().getResourceAsStream("/input.txt");

Of course there is other ways to obtain the ServletContext instance.

回答2:

When using getResource(), the resource needs to be on the classpath. Therefore you need to put input.txt somewhere under the classes directory.