Help: Servlet can't read from properties file

Question

I am working on a web application running in Tomcat on Linux.My java source file reads some parameters from a properties file (data.properties)in the same directory. This works well in a simple application. However, if it is used in the Tomcat environment, it can't be read by a servlet file (LoginServlet.java). I put both the "LoginServlet.class" and "data.properties" in the following directory: /webapps/myapp/WEB-INF/classes. When I run the web application in Tomcat, the error is "data.properties not found". What is the problem? Do I need to modify my "web.xml" and/or Tomcat's "server.xml"? If so, how to modify them?
This web application contains a lot of serlets. So I don't want to hardcode the parameters into the servlet codes.
Any info will be appreciated. Thanks in advance!:)

Answer 1

Putting the properties file in webapps/myapp may or may not help.
My assumption is that you are trying to open the file by brute force, with something like
InputStream propis = new FileInputStream ("data.properties");
Properties props = new Properties ( );
props.load (propis);
What you want is to have the class loader find a file in the same place as the class file, and give you back an input stream reading from that file, which you can then pass to the Properties.load(InputStream) method. This is called a "resource," and the way to do it is:
InputStream propis = getServletContext().getResourceAsStream("data.properties");
// remaining code as above
This will cause the class loader for the servlet context (a/k/a the Web application) to find the file in the same manner as it might find a class, but instead of treating it as compiled JVM code, and loading it, it simply passes you back an InputStream from which you do whatever you want.
Cheers!
Jerry Oberle
perl -e 'printf "mailto%cg%s%cearthlink%cnet\n", 58, "oberle", 64, 46;'