/*
* Copyright (C) 2006 Google Inc.
*
* 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.elasticsearch.common.inject.matcher;
import java.lang.annotation.Annotation;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.reflect.AnnotatedElement;
import java.lang.reflect.Method;
import java.util.Objects;
/**
* Matcher implementations. Supports matching classes and methods.
*
* @author crazybob@google.com (Bob Lee)
*/
public class Matchers {
private Matchers() {
}
/**
* Returns a matcher which matches any input.
*/
public static Matcher<Object> any() {
return ANY;
}
private static final Matcher<Object> ANY = new Any();
private static class Any extends AbstractMatcher<Object> {
@Override
public boolean matches(Object o) {
return true;
}
@Override
public String toString() {
return "any()";
}
public Object readResolve() {
return any();
}
}
/**
* Inverts the given matcher.
*/
public static <T> Matcher<T> not(final Matcher<? super T> p) {
return new Not<>(p);
}
private static class Not<T> extends AbstractMatcher<T> {
final Matcher<? super T> delegate;
private Not(Matcher<? super T> delegate) {
this.delegate = Objects.requireNonNull(delegate, "delegate");
}
@Override
public boolean matches(T t) {
return !delegate.matches(t);
}
@Override
public boolean equals(Object other) {
return other instanceof Not
&& ((Not) other).delegate.equals(delegate);
}
@Override
public int hashCode() {
return -delegate.hashCode();
}
@Override
public String toString() {
return "not(" + delegate + ")";
}
}
private static void checkForRuntimeRetention(
Class<? extends Annotation> annotationType) {
Retention retention = annotationType.getAnnotation(Retention.class);
if (retention == null || retention.value() != RetentionPolicy.RUNTIME) {
throw new IllegalArgumentException("Annotation " + annotationType.getSimpleName() + " is missing RUNTIME retention");
}
}
/**
* Returns a matcher which matches elements (methods, classes, etc.)
* with a given annotation.
*/
public static Matcher<AnnotatedElement> annotatedWith(
final Class<? extends Annotation> annotationType) {
return new AnnotatedWithType(annotationType);
}
private static class AnnotatedWithType extends AbstractMatcher<AnnotatedElement> {
private final Class<? extends Annotation> annotationType;
AnnotatedWithType(Class<? extends Annotation> annotationType) {
this.annotationType = Objects.requireNonNull(annotationType, "annotation type");
checkForRuntimeRetention(annotationType);
}
@Override
public boolean matches(AnnotatedElement element) {
return element.getAnnotation(annotationType) != null;
}
@Override
public boolean equals(Object other) {
return other instanceof AnnotatedWithType
&& ((AnnotatedWithType) other).annotationType.equals(annotationType);
}
@Override
public int hashCode() {
return 37 * annotationType.hashCode();
}
@Override
public String toString() {
return "annotatedWith(" + annotationType.getSimpleName() + ".class)";
}
}
/**
* Returns a matcher which matches elements (methods, classes, etc.)
* with a given annotation.
*/
public static Matcher<AnnotatedElement> annotatedWith(
final Annotation annotation) {
return new AnnotatedWith(annotation);
}
private static class AnnotatedWith extends AbstractMatcher<AnnotatedElement> {
private final Annotation annotation;
AnnotatedWith(Annotation annotation) {
this.annotation = Objects.requireNonNull(annotation, "annotation");
checkForRuntimeRetention(annotation.annotationType());
}
@Override
public boolean matches(AnnotatedElement element) {
Annotation fromElement = element.getAnnotation(annotation.annotationType());
return fromElement != null && annotation.equals(fromElement);
}
@Override
public boolean equals(Object other) {
return other instanceof AnnotatedWith
&& ((AnnotatedWith) other).annotation.equals(annotation);
}
@Override
public int hashCode() {
return 37 * annotation.hashCode();
}
@Override
public String toString() {
return "annotatedWith(" + annotation + ")";
}
}
/**
* Returns a matcher which matches subclasses of the given type (as well as
* the given type).
*/
public static Matcher<Class> subclassesOf(final Class<?> superclass) {
return new SubclassesOf(superclass);
}
private static class SubclassesOf extends AbstractMatcher<Class> {
private final Class<?> superclass;
SubclassesOf(Class<?> superclass) {
this.superclass = Objects.requireNonNull(superclass, "superclass");
}
@Override
public boolean matches(Class subclass) {
return superclass.isAssignableFrom(subclass);
}
@Override
public boolean equals(Object other) {
return other instanceof SubclassesOf
&& ((SubclassesOf) other).superclass.equals(superclass);
}
@Override
public int hashCode() {
return 37 * superclass.hashCode();
}
@Override
public String toString() {
return "subclassesOf(" + superclass.getSimpleName() + ".class)";
}
}
/**
* Returns a matcher which matches objects equal to the given object.
*/
public static Matcher<Object> only(Object value) {
return new Only(value);
}
private static class Only extends AbstractMatcher<Object> {
private final Object value;
Only(Object value) {
this.value = Objects.requireNonNull(value, "value");
}
@Override
public boolean matches(Object other) {
return value.equals(other);
}
@Override
public boolean equals(Object other) {
return other instanceof Only
&& ((Only) other).value.equals(value);
}
@Override
public int hashCode() {
return 37 * value.hashCode();
}
@Override
public String toString() {
return "only(" + value + ")";
}
}
/**
* Returns a matcher which matches only the given object.
*/
public static Matcher<Object> identicalTo(final Object value) {
return new IdenticalTo(value);
}
private static class IdenticalTo extends AbstractMatcher<Object> {
private final Object value;
IdenticalTo(Object value) {
this.value = Objects.requireNonNull(value, "value");
}
@Override
public boolean matches(Object other) {
return value == other;
}
@Override
public boolean equals(Object other) {
return other instanceof IdenticalTo
&& ((IdenticalTo) other).value == value;
}
@Override
public int hashCode() {
return 37 * System.identityHashCode(value);
}
@Override
public String toString() {
return "identicalTo(" + value + ")";
}
}
/**
* Returns a matcher which matches classes in the given package. Packages are specific to their
* classloader, so classes with the same package name may not have the same package at runtime.
*/
public static Matcher<Class> inPackage(final Package targetPackage) {
return new InPackage(targetPackage);
}
private static class InPackage extends AbstractMatcher<Class> {
private final transient Package targetPackage;
private final String packageName;
InPackage(Package targetPackage) {
this.targetPackage = Objects.requireNonNull(targetPackage, "package");
this.packageName = targetPackage.getName();
}
@Override
public boolean matches(Class c) {
return c.getPackage().equals(targetPackage);
}
@Override
public boolean equals(Object other) {
return other instanceof InPackage
&& ((InPackage) other).targetPackage.equals(targetPackage);
}
@Override
public int hashCode() {
return 37 * targetPackage.hashCode();
}
@Override
public String toString() {
return "inPackage(" + targetPackage.getName() + ")";
}
public Object readResolve() {
return inPackage(Package.getPackage(packageName));
}
}
/**
* Returns a matcher which matches classes in the given package and its subpackages. Unlike
* {@link #inPackage(Package) inPackage()}, this matches classes from any classloader.
*
* @since 2.0
*/
public static Matcher<Class> inSubpackage(final String targetPackageName) {
return new InSubpackage(targetPackageName);
}
private static class InSubpackage extends AbstractMatcher<Class> {
private final String targetPackageName;
InSubpackage(String targetPackageName) {
this.targetPackageName = targetPackageName;
}
@Override
public boolean matches(Class c) {
String classPackageName = c.getPackage().getName();
return classPackageName.equals(targetPackageName)
|| classPackageName.startsWith(targetPackageName + ".");
}
@Override
public boolean equals(Object other) {
return other instanceof InSubpackage
&& ((InSubpackage) other).targetPackageName.equals(targetPackageName);
}
@Override
public int hashCode() {
return 37 * targetPackageName.hashCode();
}
@Override
public String toString() {
return "inSubpackage(" + targetPackageName + ")";
}
}
/**
* Returns a matcher which matches methods with matching return types.
*/
public static Matcher<Method> returns(
final Matcher<? super Class<?>> returnType) {
return new Returns(returnType);
}
private static class Returns extends AbstractMatcher<Method> {
private final Matcher<? super Class<?>> returnType;
Returns(Matcher<? super Class<?>> returnType) {
this.returnType = Objects.requireNonNull(returnType, "return type matcher");
}
@Override
public boolean matches(Method m) {
return returnType.matches(m.getReturnType());
}
@Override
public boolean equals(Object other) {
return other instanceof Returns
&& ((Returns) other).returnType.equals(returnType);
}
@Override
public int hashCode() {
return 37 * returnType.hashCode();
}
@Override
public String toString() {
return "returns(" + returnType + ")";
}
}
}