files no longer readable

Question

I have a Java project which has this file structure (shown in Eclipse):

ProjectName
+- Deployment Descriptor: ProjectName
¦- Java Resources:src
   ¦- Package1
      -MyClass.java
¦- FileFolder
   -MyFile.txt

And so far from myClass I'm able to read MyFile.txt using:

try
{
    reader = new BufferedReader(new FileReader(new File("FileFolder/MyFile.txt")));

while((line=reader.readLine())!=null)
{
    line=line.trim();
    myVector.add(line);
}
reader.close();
}
catch(Exception e)
{
     e.printStackTrace();
}

But when I put Package1 into a Dynamic Web Project AND the FileFolder folder in root, the file is no longer found.

Does anyone know how to read the file?

Thanks in advance!

Answer 1

Dynamic Web Projects generate WAR files.

The server may or may not expand the WAR file back to a file system structure.

You're best off using the Class or ClassLoader .getResourceAsStream("/FileFolder/MyFile.txt") which can read files from JAR/WAR files, and returns an InputStream.

Example:

reader = new BufferedReader(new InputStreamReader(this.getClass().getResourceAsStream("/FileFolder/MyFile.txt")));

Edit: If this is from a Servlet, consider using gawi's answer instead.

Edit 2: If this is in a static method, you'll need to use MyClass.class instead of this.getClass(), where MyClass is the class name.

Answer 2

You are opening a file using a path relative to the current working directory. That's not likely to work on a web app container because the current working directory will not be the root of your application.

Furthermore, you file might not be on the file system but rather in a WAR file.

The proper way to open a file in a webapp is to use the ServletContext.getResourceAsStream() method.