/*
* Copyright 2002-2016 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.integration.test.matcher;
import java.lang.reflect.Method;
import org.hamcrest.BaseMatcher;
/**
* This class was copied from JUnit to avoid using it from org.junit.internal (causing a backwards compatibility issue).
* If you want to extend this class use a recent version of JUnit, and extend
* <code>org.junit.matchers.TypeSafeMatcher</code>
* <p>
* Convenient base class for Matchers that require a non-null value of a specific type.
* This simply implements the null check, checks the type and then casts.
*
* @author Joe Walnes
*/
abstract class TypeSafeMatcher<T> extends BaseMatcher<T> {
private final Class<?> expectedType;
/**
* Subclasses should implement this. The item will already have been checked for
* the specific type and will never be null.
*
* @param item The item.
* @return true if matches.
*/
public abstract boolean matchesSafely(T item);
protected TypeSafeMatcher() {
expectedType = findExpectedType(getClass());
}
private static Class<?> findExpectedType(Class<?> fromClass) {
for (Class<?> c = fromClass; c != Object.class; c = c.getSuperclass()) {
for (Method method : c.getDeclaredMethods()) {
if (isMatchesSafelyMethod(method)) {
return method.getParameterTypes()[0];
}
}
}
throw new Error("Cannot determine correct type for matchesSafely() method.");
}
private static boolean isMatchesSafelyMethod(Method method) {
return method.getName().equals("matchesSafely")
&& method.getParameterTypes().length == 1
&& !method.isSynthetic();
}
protected TypeSafeMatcher(Class<T> expectedType) {
this.expectedType = expectedType;
}
/**
* Method made final to prevent accidental override.
* If you need to override this, there's no point on extending TypeSafeMatcher.
* Instead, extend the {@link BaseMatcher}.
*/
@Override
@SuppressWarnings({ "unchecked" })
public final boolean matches(Object item) {
return item != null
&& expectedType.isInstance(item)
&& matchesSafely((T) item);
}
}