```
@Documented
@Retention(RUNTIME)
@Target({METHOD,CONSTRUCTOR})
@ConditionalPostconditionAnnotation(qualifier=NonNull.class)
@InheritedAnnotation
@Repeatable(List.class)
public @interface EnsuresNonNullIf
```
Indicates that the given expressions are non-null, if the method returns the given result (either true or false).
Here are ways this conditional postcondition annotation can be used:
Method parameters: A common example is that the equals method is annotated as follows:
```
  @EnsuresNonNullIf(expression="#1", result=true)
   public boolean equals(@Nullable Object obj) { ... }
```
because, if equals returns true, then the first (#1) argument to equals was not null.
Fields: The value expressions can refer to fields, even private ones. For example:
```
  @EnsuresNonNullIf(expression="this.derived", result=true)
   public boolean isDerived() {
     return (this.derived != null);
   }
```
As another example, an Iterator may cache the next value that will be returned, in which case its hasNext method could be annotated as:
```
  @EnsuresNonNullIf(expression="next_cache", result=true)
   public boolean hasNext() {
     if (next_cache == null) {
       return false;
     }
     ...
   }
```
An EnsuresNonNullIf annotation that refers to a private field is useful for verifying that client code performs needed checks in the right order, even if the client code cannot directly affect the field.
Method calls: If Class.isArray() returns true, then Class.getComponentType() returns non-null. You can express this relationship as:
```
  @EnsuresNonNullIf(expression="getComponentType()", result=true)
   public native @Pure boolean isArray();
```
You can write two @EnsuresNonNullIf annotations on a single method:
```
     @EnsuresNonNullIf(expression="outputFile", result=true)
     @EnsuresNonNullIf(expression="memoryOutputStream", result=false)
     public boolean isThresholdExceeded() { ... }
 
```
See Also:

NonNull, EnsuresNonNull, NullnessChecker

See the Checker Framework Manual:
Nullness Checker

Required Element Summary

Required Elements
Modifier and Type	Required Element	Description
`java.lang.String[]`	`expression`	Returns Java expression(s) that are non-null after the method returns the given result.
`boolean`	`result`	Returns the return value of the method under which the postcondition holds.

- Element Detail
  - expression
```
java.lang.String[] expression
```
    Returns Java expression(s) that are non-null after the method returns the given result.
    
    Returns:
    
    Java expression(s) that are non-null after the method returns the given result
    
    See the Checker Framework Manual:
    Syntax of Java expressions
- - result
```
boolean result
```
    Returns the return value of the method under which the postcondition holds.
    
    Returns:
    
    the return value of the method under which the postcondition holds

Annotation Type EnsuresNonNullIf

Required Element Summary

Element Detail

expression

result