Best way to check for null values in Java?

Question

Before calling a function of an object, I need to check if the object is null, to avoid throwing a NullPointerException.

What is the best way to go abou

Answer 1

Method 4 is my preferred method. The short circuit of the && operator makes the code the most readable. Method 3, Catching NullPointerException, is frowned upon most of the time when a simple null check would suffice.

Answer 2

Simple one line Code to check for null :

namVar == null ? codTdoForNul() : codTdoForFul();

Answer 3

If you control the API being called, consider using Guava's Optional class

More info here. Change your method to return an Optional<Boolean> instead of a Boolean.

This informs the calling code that it must account for the possibility of null, by calling one of the handy methods in Optional

Answer 4

Your last proposal is the best.

if (foo != null && foo.bar()) {
    etc...
}

Because:

1. It is easier to read.
2. It is safe : foo.bar() will never be executed if foo == null.
3. It prevents from bad practice such as catching NullPointerExceptions (most of the time due to a bug in your code)
4. It should execute as fast or even faster than other methods (even though I think it should be almost impossible to notice it).