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I have an App Engine servlet which creates objects based on a JSON file (stored in a "Resources" folder under WEB-INF). I handle the parsing of the file in a separate class:

public class EventParser
{
    static Gson gson = new Gson();
    static String fileName = "/SOServices-war/src/main/webapp/WEB-INF/Resources/mockEvents.json";
    static File file = new File(fileName);

    public static List<Event> readDataFromJSON() throws IOException
    {
        InputStreamReader inReader = new InputStreamReader(new FileInputStream(file), "UTF-8");
        String stringFromRes = null;
        try (BufferedReader br = new BufferedReader(inReader))
        {
            StringBuilder sb = new StringBuilder();
            String sCurrentLine;

            while ((sCurrentLine = br.readLine()) != null)
            {
                sb.append(sCurrentLine);
                sb.append(System.lineSeparator());
            }

            stringFromRes = sb.toString();

        }
        catch (IOException e)
        {
            e.printStackTrace();
        }

        List<Event> events = new ArrayList<Event>();
        Type listOfTestObject = new TypeToken<List<Event>>(){}.getType();
        events = gson.fromJson(stringFromRes, listOfTestObject);

        return events;
    }
}

It is important to point out that this used to work using "WEB-INF/" as path, but I've recreated the project (using the new Maven tutorial) and it has a new folder structure: instead of /war/WEB-INF, it looks like /AppName-war/src/main/webapp/WEB-INF. I don't really understand how it could affect things, but I can't seem to get file reading working again. So far I've tried:

  • just using " instead of "WEB-INF/"
  • putting the files under the webapp folder directly
  • using the old method
  • using the string provided in this code snipped, but without the dash at the beginning

Neither of them worked, the files couldn't be found on local development environment (app is not deployed yet).

Update

Big thanks to McDowell for providing me the link, it was a bit different, but it helped a lot. I am now calling the readDataFromJSON() method with a servletContext parameter like so:

List<Event> events = EventParser.readDataFromJSON(this.getServletContext());

And then in the parser:

String filePath =  context.getRealPath(fileName);
InputStreamReader inReader = new InputStreamReader(new FileInputStream(new File(filePath)), "UTF-8");

This solves my issue.

József Vesza
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    possible duplicate of [File path to resource in our war/WEB-INF folder?](http://stackoverflow.com/questions/4340653/file-path-to-resource-in-our-war-web-inf-folder) – McDowell Apr 18 '14 at 13:53
  • I'm not sure. I'm not making the parsing in any of the servlets but in a separate class. Also in the previous project setup (using eclipse + app engine plugin) I was able to read war/WEB-INF resources just as I wrote, I think this is different now. – József Vesza Apr 18 '14 at 14:11
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    You should not assume the WAR file is exploded on the file system. Consider adding these resources to your classpath and [reading them from there](http://stackoverflow.com/questions/403256). – McDowell Apr 18 '14 at 14:30
  • I've managed to solve the issue by passing the servletContext from my servlet to the parsing method and using getRealPath(), something like the solution in the linked question. Thank you for the suggestions, I will update my question with the answer shortly. – József Vesza Apr 18 '14 at 14:46

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