Fields, parameters and return values marked ``++@NotNull++``, ``++@NonNull++``, or ``++@Nonnull++`` are assumed to have non-null values and are not typically null-checked before use. Therefore setting one of these values to ``++null++``, or failing to set such a class field in a constructor, could cause ``++NullPointerException++``s at runtime.
=== Noncompliant code example
[source,java]
----
public class MainClass {
@Nonnull
private String primary;
private String secondary;
public MainClass(String color) {
if (color != null) {
secondary = null;
}
primary = color; // Noncompliant; "primary" is Nonnull but could be set to null here
}
public MainClass() { // Noncompliant; "primary" is Nonnull but is not initialized
}
@Nonnull
public String indirectMix() {
String mix = null;
return mix; // Noncompliant; return value is Nonnull, but null is returned.
