org.hamcrest

Class TypeSafeDiagnosingMatcher<T>

java.lang.Object

org.hamcrest.BaseMatcher<T>

org.hamcrest.TypeSafeDiagnosingMatcher<T>

Type Parameters:

T -

All Implemented Interfaces:

Matcher<T>, SelfDescribing

Direct Known Subclasses:

Every, FeatureMatcher, HasPropertyWithValue, HasXPath, IsCollectionContaining, IsEventFrom, IsIterableContainingInAnyOrder, IsIterableContainingInOrder, SamePropertyValuesAs

public abstract class TypeSafeDiagnosingMatcher<T>
extends BaseMatcher<T>

Convenient base class for Matchers that require a non-null value of a specific type and that will report why the received value has been rejected. This implements the null check, checks the type and then casts. To use, implement

matchesSafely()

.

Author:

Neil Dunn, Nat Pryce, Steve Freeman

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	TypeSafeDiagnosingMatcher() The default constructor for simple sub types
protected	TypeSafeDiagnosingMatcher(Class<?> expectedType) Use this constructor if the subclass that implements matchesSafely is not the class that binds <T> to a type.
protected	TypeSafeDiagnosingMatcher(ReflectiveTypeFinder typeFinder) Use this constructor if the subclass that implements matchesSafely is not the class that binds <T> to a type.

Method Summary

Methods

Modifier and Type	Method and Description
void	describeMismatch(Object item, Description mismatchDescription) Generate a description of why the matcher has not accepted the item.
boolean	matches(Object item) Evaluates the matcher for argument item.
protected abstract boolean	matchesSafely(T item, Description mismatchDescription) Subclasses should implement this.

Methods inherited from class org.hamcrest.BaseMatcher

_dont_implement_Matcher___instead_extend_BaseMatcher_, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.hamcrest.SelfDescribing

describeTo

Constructor Detail

TypeSafeDiagnosingMatcher

protected TypeSafeDiagnosingMatcher(Class<?> expectedType)

Use this constructor if the subclass that implements matchesSafely is not the class that binds <T> to a type.

Parameters:

expectedType - The expectedType of the actual value.

TypeSafeDiagnosingMatcher

protected TypeSafeDiagnosingMatcher(ReflectiveTypeFinder typeFinder)

Use this constructor if the subclass that implements matchesSafely is not the class that binds <T> to a type.

Parameters:

typeFinder - A type finder to extract the type

TypeSafeDiagnosingMatcher

protected TypeSafeDiagnosingMatcher()

The default constructor for simple sub types

Method Detail

matchesSafely

protected abstract boolean matchesSafely(T item,
                    Description mismatchDescription)

Subclasses should implement this. The item will already have been checked for the specific type and will never be null.

matches

public final boolean matches(Object item)

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:

item - the object against which the matcher is evaluated.

Returns:

true if item matches, otherwise false.

See Also:

BaseMatcher

describeMismatch

public final void describeMismatch(Object item,
                    Description mismatchDescription)

Description copied from interface: Matcher

Generate a description of why the matcher has not accepted the item. The description will be part of a larger description of why a matching failed, so it should be concise. This method assumes that matches(item) is false, but will not check this.

Specified by:

describeMismatch in interface Matcher<T>

Overrides:

describeMismatch in class BaseMatcher<T>

Parameters:

item - The item that the Matcher has rejected.

mismatchDescription - The description to be built or appended to.