getResourceAsStream() is always returning null [duplicate]

To my knowledge the file has to be right in the folder where the 'this' class resides, i.e. not in WEB-INF/classes but nested even deeper (unless you write in a default package):

net/domain/pkg1/MyClass.java  
net/domain/pkg1/abc.txt

Putting the file in to your java sources should work, compiler copies that file together with class files.

A call to Class#getResourceAsStream(String) delegates to the class loader and the resource is searched in the class path. In other words, you current code won't work and you should put abc.txt in WEB-INF/classes, or in WEB-INF/lib if packaged in a jar file.

Or use ServletContext.getResourceAsStream(String) which allows servlet containers to make a resource available to a servlet from any location, without using a class loader. So use this from a Servlet:

this.getServletContext().getResourceAsStream("/WEB-INF/abc.txt") ;

But is there a way I can call getServletContext from my Web Service?

If you are using JAX-WS, then you can get a WebServiceContext injected:

@Resource
private WebServiceContext wsContext;

And then get the ServletContext from it:

ServletContext sContext= wsContext.getMessageContext()
                             .get(MessageContext.SERVLET_CONTEXT));