Thread.currentThread().getContextClassLoader().getResourceAsStream() returns null

Question

I have following code block in my application;

InputStream in = Thread.currentThread().getContextClassLoader().getResourceAsStream(FilePath);

Here 'FilePath' is an absolute path of the file.

Above code works fine in linux and in windows when i run the application in normal mode.(ie: in command prompt) But this is NOT working, when I run the application as a windows service. I get input stream as 'null'.

Anyone encountered such issue before? I could not find any information regarding this other than java classloaders . Here we use "ContextClassLoader", which is the right classloader to be used..

Any clue on this?

Solution

I think this happens because you have "." (the current folder) on the classpath. That is a) a bad idea and b) makes your app break in odd ways.

What you need to understand is the difference between a file and a resource. A file is something outside of the classpath.

You should use File and FileReader to access them.

A resource is something on the classpath. Paths for resources always use / as file separator and not File.separator.

Another way to fix this is to add $HOME/repository/ (Linux) or %HOME%/repository/ to the classpath and load the resource using "resources/api_templates/api.xml". for this to work, resources must be a folder in $HOME/repository/.

If you don't do this, then all files in your home directory (or whatever directory you happen to start the application in) are added as resources to the classpath.