Java Best Practices- String literals at left

It is always a good practice in Java to place String literals at left while comparing a String lteral with a String variable using equals or equalsIgnoreCase. The idea is if you keep variables at left, it might result in null pointer exception.

For example

String a=null;
System.out.println("0".equals(a)); //works fine
System.out.println(a.equals("0"	)); //results in null pointer exception