How to define a relative path in java

Here is the structure of my project :

I need to read config.properties inside MyClass.java. I tried to do so with a relative path as follows :

// Code called from MyClass.java
File f1 = new File("..\\..\\..\\config.properties");  
String path = f1.getPath(); 
prop.load(new FileInputStream(path));

This gives me the following error :

..\..\..\config.properties (The system cannot find the file specified)

How can I define a relative path in Java? I’m using jdk 1.6 and working on windows.