How to read files on server from a java program?

I am fairly new to JSP programming. I have an issue with reading files. I am trying to call method of a normal java file from a jsp program. The method I am trying to call does some IO operation on Files. I have the files in the same directory as my class files on server that is in WEB-INF/classes folder. In my java program, I am giving just the file name to open because the files and the classes are in the same directory. But this is not working.
What exactly should I do to read a file from a java program, that is running on the server?
Any help is appreciated.

String realFilePath = application.getRealPath("/WEB-INF/myFile.txt");
File fileToOpen = new File(realFilePath);
out.println(fileToOpen.getAbsolutePath() + ": exists? " + fileToOpen.exists());in this case "application" is a reference to the ServletContext.
It is an implicit variable in a JSP. In a servlet:
ServletContext application = getServletConfig().getServletContext();

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