Interface MapConstraint<K,V>

@GwtCompatible
@Beta
@Deprecated
public interface MapConstraint<K,V>

Deprecated.

Use

invalid reference

Preconditions

for basic checks. In place of constrained maps, we encourage you to check your preconditions explicitly instead of leaving that work to the map implementation. For the specific case of rejecting null, consider ImmutableMap. This class is scheduled for removal in Guava 21.0.

A constraint on the keys and values that may be added to a Map or Multimap. For example, to prevent a map from including any null keys or values, you could implement a MapConstraint like this:

public void checkKeyValue(Object key, Object value) {
  if (key == null || value == null) {
    throw new NullPointerException();
  }
}

In order to be effective, constraints should be deterministic; that is, they should not depend on state that can change (such as external state, random variables, and time) and should only depend on the value of the passed-in key and value. A non-deterministic constraint cannot reliably enforce that all the collection's elements meet the constraint, since the constraint is only enforced when elements are added.

Since:

3.0

See Also:

• MapConstraints
• Constraint

Method Summary

Modifier and Type	Method	Description
void	checkKeyValue(K key, V value)	Deprecated. Throws a suitable RuntimeException if the specified key or value is illegal.
String	toString()	Deprecated. Returns a brief human readable description of this constraint, such as "Not null".

Method Details

checkKeyValue

void checkKeyValue(@Nullable
 K key,
 @Nullable
 V value)

Deprecated.

Throws a suitable RuntimeException if the specified key or value is illegal. Typically this is either a NullPointerException, an IllegalArgumentException, or a ClassCastException, though an application-specific exception class may be used if appropriate.

toString

String toString()

Deprecated.

Returns a brief human readable description of this constraint, such as "Not null".

Overrides:

toString in class Object