First let's clarify something: You mention that after assigning null to the variable you could forget to initialize it, but by assigning null to it you are in effect initializing it.

	public static void main (String args[]){
		String s;		
		System.out.println(s); // compiler error variable may not be initialized
	}

vs 

	public static void main (String args[]){
		String s=null;		
		System.out.println(s); // no compiler error
		System.out.println(s.equals("helo")); // but this will generate an exception
	}

So after you do `String s=null;` there's is no way that you could *forget to initialize* because you did initialize it.

That being clear, I would recommend you to use a "smart default". In your case perhaps the empty string `""` would be a good default value if you want to avoid `NullPointerException`. In the other hand, sometimes it is desirable that the program produce an exception because it indicates something wrong happened under the hood that should not have happened.