It is preferable to place string literals on the left-hand side of an equals() or equalsIgnoreCase() method call.
This prevents null pointer exceptions from being raised, as a string literal can never be null by definition.
Noncompliant code example
String myString = null;
System.out.println("Equal? " + myString.equals("foo")); // Noncompliant; will raise a NPE
System.out.println("Equal? " + (myString != null && myString.equals("foo"))); // Noncompliant; null check could be removed
Compliant solution
System.out.println("Equal?" + "foo".equals(myString)); // properly deals with the null case
