it.tidalwave.role.ui.javafx.impl.util.ReflectionUtils Maven / Gradle / Ivy
/*
* #%L
* *********************************************************************************************************************
*
* SteelBlue
* http://steelblue.tidalwave.it - git clone [email protected]:tidalwave/steelblue-src.git
* %%
* Copyright (C) 2015 - 2015 Tidalwave s.a.s. (http://tidalwave.it)
* %%
*
* *********************************************************************************************************************
*
* 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.
*
* *********************************************************************************************************************
*
* $Id$
*
* *********************************************************************************************************************
* #L%
*/
package it.tidalwave.role.ui.javafx.impl.util;
import javax.annotation.CheckForNull;
import javax.annotation.Nonnull;
import java.lang.reflect.Array;
import java.lang.reflect.Field;
import java.lang.reflect.GenericArrayType;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.lang.reflect.TypeVariable;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.inject.Inject;
/***********************************************************************************************************************
*
* Just slightly adapted from http://www.artima.com/weblogs/viewpost.jsp?thread=208860
*
* @author Ian Robertson
* @author Fabrizio Giudici
* @version $Id$
*
**********************************************************************************************************************/
public class ReflectionUtils
{
/*******************************************************************************************************************
*
*
*
******************************************************************************************************************/
public static void injectDependencies (final @Nonnull Object object, final @Nonnull Map, Object> beans)
{
for (final Field field : object.getClass().getDeclaredFields())
{
if (field.getAnnotation(Inject.class) != null)
{
field.setAccessible(true);
final Class type = field.getType();
final Object dependency = beans.get(type);
if (dependency == null)
{
throw new RuntimeException("Can't inject " + object + "." + field.getName());
}
try
{
field.set(object, dependency);
}
catch (IllegalArgumentException | IllegalAccessException e)
{
throw new RuntimeException(e);
}
}
}
}
/*******************************************************************************************************************
*
* Get the actual type arguments a child class has used to extend a generic base class.
*
* @param baseClass the base class
* @param childClass the child class
* @return a list of the raw classes for the actual type arguments.
*
******************************************************************************************************************/
public static List> getTypeArguments (final @Nonnull Class baseClass,
final @Nonnull Class childClass)
{
final Map resolvedTypes = new HashMap<>();
Type type = childClass;
// start walking up the inheritance hierarchy until we hit baseClass
while (!getClass(type).equals(baseClass))
{
if (type instanceof Class)
{
// there is no useful information for us in raw types, so just keep going.
type = ((Class)type).getGenericSuperclass();
}
else
{
final ParameterizedType parameterizedType = (ParameterizedType) type;
final Class rawType = (Class) parameterizedType.getRawType();
final Type[] actualTypeArguments = parameterizedType.getActualTypeArguments();
final TypeVariable[] typeParameters = rawType.getTypeParameters();
for (int i = 0; i < actualTypeArguments.length; i++)
{
resolvedTypes.put(typeParameters[i], actualTypeArguments[i]);
}
if (!rawType.equals(baseClass))
{
type = rawType.getGenericSuperclass();
}
}
}
// finally, for each actual type argument provided to baseClass, determine (if possible)
// the raw class for that type argument.
Type[] actualTypeArguments;
if (type instanceof Class)
{
actualTypeArguments = ((Class)type).getTypeParameters();
}
else
{
actualTypeArguments = ((ParameterizedType)type).getActualTypeArguments();
}
final List> typeArgumentsAsClasses = new ArrayList<>();
// resolve types by chasing down type variables.
for (Type baseType : actualTypeArguments)
{
while (resolvedTypes.containsKey(baseType))
{
baseType = resolvedTypes.get(baseType);
}
typeArgumentsAsClasses.add(getClass(baseType));
}
return typeArgumentsAsClasses;
}
/*******************************************************************************************************************
*
*
*
******************************************************************************************************************/
@CheckForNull
public static Class getClass (final @Nonnull Type type)
{
if (type instanceof Class)
{
return (Class)type;
}
else if (type instanceof ParameterizedType)
{
return getClass(((ParameterizedType)type).getRawType());
}
else if (type instanceof GenericArrayType)
{
final Type componentType = ((GenericArrayType)type).getGenericComponentType();
final Class componentClass = getClass(componentType);
if (componentClass == null)
{
return null;
}
return Array.newInstance(componentClass, 0).getClass();
}
else
{
return null;
}
}
}