Java getResourceAsStream JAR inside WAR

I have a Java webapp WAR file that depends on multiple jars in it's WEB-INF\lib directory. One of these JARS needs to load some config files by doing class.getClassLoader().getResourceAsStream(...). However the InputStream resturns null. Is there a problem with taking this approach when the JAR is inside a WAR? The app is deployed on Tomcat6.

EDIT MORE INFO:

I'm tring to load in SQL queries from files so I can run them. These are located in a separate DAO jar within the web app's WAR, under WEB-INF/lib

mywebapp.war
        -- WEB-INF
          -- lib
             -- mydao.jar
               ---- com/companyname/queries
                   -- query1.sql
                   -- query2.sql
                   -- query3.sql
                   .开发者_如何转开发..

CODE USING TO LOAD CLASSES

public class QueryLoader {

 private static final Logger LOGGER = Logger.getLogger(QueryLoader.class.getName());

public String loadQuery(String fileName) {
  final String newline = "\n";

  BufferedReader reader = new BufferedReader(new InputStreamReader(         
        QueryLoader.class.getClassLoader().getResourceAsStream(
              "/com/companyname/queries/" + fileName)));
  StringBuilder sb = new StringBuilder();
  String line;
  try {
     while ((line = reader.readLine()) != null) {
        sb.append(line);
        sb.append(newline);
     }
  } catch (IOException e) {
     LOGGER.error(e);
  }

I have also tried changing the getResourceAsStream line to

Thread.currentThread().getContextClassLoader().getResourceAsStream(

without success.

My development environment is MS Windows Vista and but I encounter the same error when running it on this environment and on Ubuntu.

Assuming you're not making the rookie mistake of putting QueryLoader in a different JAR, the only problem I can see is that you're using File.separator yet appear (from your use of \) to be using Windows. When using getResourceAsStream, the separator is always a forward slash (/) just as if you're using a URL.

If I change that I get this:

QueryLoader.class.getClassLoader().getResourceAsStream(
          "/com/companyname/queries/" + fileName)

Of course, if QueryLoader is in the com.companyname.queries package (along with the queries themselves) then you should simply do this:

QueryLoader.class.getResourceAsStream(fileName)

Simple as that. (It's documented that Class.getResourceAsStream qualifies relative filenames with the name of the containing package.)

Managed to get it to work by using Spring's resource loader instead

public String loadQuery(String fileName) {
  final String newline = "\n";

  ApplicationContext ctx = new ClassPathXmlApplicationContext();
  Resource res = ctx.getResource("classpath:/com/msi/queries/" + fileName);
  BufferedReader reader;
  StringBuilder sb = new StringBuilder();
  try {
     reader = new BufferedReader(new InputStreamReader(res.getInputStream()));
     String line;

     while ((line = reader.readLine()) != null) {
        sb.append(line);
        sb.append(newline);
     }
  } catch (IOException e) {
     LOGGER.error(e);
  }

  return sb.toString();

}

It should work, but you need to take care that you use the correct class loader.