When comparing String literals to String variables I often come across the following style of code:
final String MY_NAME = "Steve";
void myMethod(String aName) {
if (aName.equals(MY_NAME)) {
// do something
}
}If I were to call the above method with a null argument, it would throw a NullPointerException. Of course you could add a defensive check but you would also be adding complexity and increasing method/codebase size:
final String MY_NAME = "Steve";
void myMethod(String aName) {
// defensive check to avoid NullPointerException
if (aName == null) {
return;
}
if (aName.equals(MY_NAME)) {
// do something
}
}A better solution to defending against a NullPointerException in such a scenario is to simply place the literal first. the String.equals methods will happily handle a null argument and you know your String literal will never be null (unless you explicitly set it of course):
final String MY_NAME = "Steve";
void myMethod(String aName) {
if (MY_NAME.equals(aName)) {
// do something
}
} 
