Package org.hamcrest.core

Class IsNull<T>

java.lang.Object
org.hamcrest.BaseMatcher<T>
org.hamcrest.core.IsNull<T>
Type Parameters:
T - the matched value type
All Implemented Interfaces:
Matcher<T>, SelfDescribing
public class IsNull<T> extends BaseMatcher<T>
Is the value null?

  • Constructor Details

  • Method Details

    • matches

      public boolean matches(Object o)
      Description copied from interface: Matcher
      Evaluates the matcher for argument item. This method matches against Object, instead of the generic type T. This is because the caller of the Matcher does not know at runtime what the type is (because of type erasure with Java generics). It is down to the implementations to check the correct type.
      Parameters:
      o - the object against which the matcher is evaluated.
      Returns:
      true if item matches, otherwise false.
      See Also:

    • describeTo

      public void describeTo(Description description)
      Description copied from interface: SelfDescribing
      Generates a description of the object. The description may be part of a description of a larger object of which this is just a component, so it should be worded appropriately.
      Parameters:
      description - The description to be built or appended to.

    • nullValue

      public static Matcher<Object> nullValue()

      Creates a matcher that matches if examined object is null.

      For example: 
      assertThat(cheese, is(nullValue())
      Returns:
      The matcher

    • notNullValue

      public static Matcher<Object> notNullValue()
      A shortcut to the frequently used not(nullValue()). For example: 
      assertThat(cheese, is(notNullValue()))
      instead of: 
      assertThat(cheese, is(not(nullValue())))
      Returns:
      The matcher.

    • nullValue

      public static <T> Matcher<T> nullValue(Class<T> type)

      Creates a matcher that matches if examined object is null. Accepts a single dummy argument to facilitate type inference.

      For example: 
      assertThat(cheese, is(nullValue(Cheese.class))
      Type Parameters:
      T - the matcher type.
      Parameters:
      type - dummy parameter used to infer the generic type of the returned matcher
      Returns:
      The matcher.

    • notNullValue

      public static <T> Matcher<T> notNullValue(Class<T> type)
      A shortcut to the frequently used not(nullValue(X.class)). Accepts a single dummy argument to facilitate type inference.. For example: 
      assertThat(cheese, is(notNullValue(X.class)))
      instead of: 
      assertThat(cheese, is(not(nullValue(X.class))))
      Type Parameters:
      T - the matcher type.
      Parameters:
      type - dummy parameter used to infer the generic type of the returned matcher
      Returns:
      The matcher.