/*
* Copyright 2013 MovingBlocks
*
* 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.terasology.utilities;
import com.google.common.base.Preconditions;
import com.google.common.collect.Lists;
import com.google.common.collect.Sets;
import org.terasology.rendering.nui.UIWidget;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.List;
import java.util.Locale;
import java.util.Set;
/**
*
*/
public final class ReflectionUtil {
private ReflectionUtil() {
}
/**
* Attempts to return the type of a parameter of a parameterised field. This uses compile-time information only - the
* type should be obtained from a field with a the generic types bound.
*
* @param type
* @param index
* @return The type of the generic parameter at index for the given type, or null if it cannot be obtained.
*/
// TODO - Improve parameter lookup to go up the inheritance tree more
public static Type getTypeParameter(Type type, int index) {
if (!(type instanceof ParameterizedType)) {
return null;
}
ParameterizedType parameterizedType = (ParameterizedType) type;
if (parameterizedType.getActualTypeArguments().length < index + 1) {
return null;
}
return parameterizedType.getActualTypeArguments()[index];
}
public static Class<?> getClassOfType(Type type) {
if (type instanceof Class) {
return (Class<?>) type;
} else if (type instanceof ParameterizedType) {
return (Class<?>) ((ParameterizedType) type).getRawType();
}
return null;
}
public static Method findGetter(Field field) {
return findGetter(field.getName(), field.getDeclaringClass(), field.getType());
}
public static Method findGetter(String propertyName, Class<?> beanClass, Class<?> propertyType) {
Method result = findGetter(propertyName, beanClass);
if (result != null && propertyType.equals(result.getReturnType())) {
return result;
}
return null;
}
public static Method findGetter(String propertyName, Class<?> beanClass) {
Method result = findMethod(beanClass, "get" + propertyName.substring(0, 1).toUpperCase(Locale.ENGLISH) + propertyName.substring(1));
if (result != null) {
result.setAccessible(true);
return result;
}
result = findMethod(beanClass, "is" + propertyName.substring(0, 1).toUpperCase(Locale.ENGLISH) + propertyName.substring(1));
if (result != null) {
result.setAccessible(true);
return result;
}
return null;
}
public static Method findSetter(Field field) {
return findSetter(field.getName(), field.getDeclaringClass(), field.getType());
}
public static Method findSetter(String propertyName, Class<?> beanClass, Class<?> propertyType) {
String setterName = "set" + propertyName.substring(0, 1).toUpperCase(Locale.ENGLISH) + propertyName.substring(1);
Method result = findMethod(beanClass, setterName, propertyType);
if (result != null) {
result.setAccessible(true);
}
return result;
}
public static Method findMethod(Class<?> targetType, String methodName, Class<?>... parameters) {
try {
return targetType.getMethod(methodName, parameters);
} catch (NoSuchMethodException me) {
// We're expecting not to find methods
return null;
}
}
/**
* Returns an ordered list of super classes and interfaces for the given class, that have a common base class.
* The set is ordered with the deepest interface first, through all the interfaces, and then all the super classes.
*
* @param forClass
* @param baseClass
* @return an ordered list of super classes and interfaces for the given class, that have a common base class.
*/
public static <T> List<Class<? extends T>> getInheritanceTree(Class<? extends T> forClass, Class<T> baseClass) {
Set<Class<? extends T>> result = Sets.newLinkedHashSet();
for (Class<?> interfaceType : forClass.getInterfaces()) {
if (baseClass.isAssignableFrom(interfaceType)) {
addInterfaceToInheritanceTree((Class<? extends T>) interfaceType, baseClass, result);
}
}
addClassToInheritanceTree(forClass, baseClass, result);
return Lists.newArrayList(result);
}
private static <T> void addClassToInheritanceTree(Class<? extends T> element, Class<T> baseClass, Set<Class<? extends T>> result) {
for (Class<?> interfaceType : element.getInterfaces()) {
if (baseClass.isAssignableFrom(interfaceType)) {
addInterfaceToInheritanceTree((Class<? extends T>) interfaceType, baseClass, result);
}
}
if (element.getSuperclass() != null && baseClass.isAssignableFrom(element.getSuperclass())) {
addClassToInheritanceTree((Class<? extends T>) element.getSuperclass(), baseClass, result);
}
result.add(element);
}
private static <T> void addInterfaceToInheritanceTree(Class<? extends T> interfaceType, Class<T> baseClass, Set<Class<? extends T>> result) {
for (Class<?> parentInterface : interfaceType.getInterfaces()) {
if (UIWidget.class.isAssignableFrom(parentInterface)) {
addInterfaceToInheritanceTree((Class<? extends T>) parentInterface, baseClass, result);
}
}
result.add(interfaceType);
}
public static <T> Class<?> getTypeParameterForSuper(Type target, Class<T> superClass, int index) {
Class targetClass = getClassOfType(target);
Preconditions.checkArgument(superClass.isAssignableFrom(targetClass), "Target must be a child of superClass");
if (superClass.isInterface()) {
return getTypeParameterForSuperInterface(target, superClass, index);
} else {
return getTypeParameterForSuperClass(target, superClass, index);
}
}
private static <T> Class<?> getTypeParameterForSuperClass(Type target, Class<T> superClass, int index) {
Class targetClass = getClassOfType(target);
if (superClass.equals(getClassOfType(targetClass.getGenericSuperclass()))) {
Type superType = targetClass.getGenericSuperclass();
if (superType instanceof ParameterizedType) {
if (((ParameterizedType) superType).getRawType().equals(superClass)) {
Type boundType = ((ParameterizedType) superType).getActualTypeArguments()[index];
if (boundType instanceof Class) {
return (Class<?>) boundType;
} else {
return null;
}
}
}
}
return getTypeParameterForSuperClass(targetClass.getGenericSuperclass(), superClass, index);
}
private static <T> Class<?> getTypeParameterForSuperInterface(Type target, Class<T> superClass, int index) {
Class targetClass = getClassOfType(target);
for (Type superType : targetClass.getGenericInterfaces()) {
if (superType instanceof ParameterizedType) {
if (((ParameterizedType) superType).getRawType().equals(superClass)) {
Type boundType = ((ParameterizedType) superType).getActualTypeArguments()[index];
if (boundType instanceof Class) {
return (Class<?>) boundType;
} else {
return null;
}
}
}
}
return getTypeParameterForSuperInterface(targetClass.getGenericSuperclass(), superClass, index);
}
}