Mega Code Archive
Get the Generic definition from a class for given class with given index
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/**
* Copyright (C) 2010 altuure <altuure [AT] gmail [DOT] com> http://www.altuure.com/projects/yagdao
*
* 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 com.altuure.yagdao.common;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
/**
* Created by IntelliJ IDEA.
* User: makkan
* Date: 04-Dec-2010
* Time: 20:14:55
* To change this template use File | Settings | File Templates.
*/
public class GenericUtils {
/**
* Get the Generic definition from a class for given class with given index.
* @param clz Implementing class
* @param class1 class with generic definition
* @param index generic index
* @return null if not found
*/
public static Type getGenericDefiniton(Class clz, Class class1, int index) {
Type[] t = getGenericDefinitons(clz, class1);
if (t != null && t.length > index)
return t[index];
return null;
}
/**
* Get the Generic definitions from a class for given class .
* @param clz Implementing class
* @param class1 class with generic definition
* @return null if not found
*/
public static Type[] getGenericDefinitons(Class clz, Class class1) {
Type[] t = null;
while (clz != null) {
t = getGenericDefinitonsThis(clz, class1);
if (t != null)
return t;
Class[] interfaces = clz.getInterfaces();
for (Class class2 : interfaces) {
t = getGenericDefinitonsThis(class2, class1);
if (t != null)
return t;
}
clz = clz.getSuperclass();
}
return t;
}
/**
* Get the Generic definitions from a class for given class without looking
* super classes.
* @param classFrom Implementing class
* @param interfaceClz class with generic definition
* @return null if not found
*/
@SuppressWarnings("unchecked")
public static Type[] getGenericDefinitonsThis(Class classFrom, Class interfaceClz) {
Type[] genericInterfaces = classFrom.getGenericInterfaces();
for (Type type : genericInterfaces) {
if (type instanceof ParameterizedType) {
ParameterizedType pt = (ParameterizedType) type;
if (interfaceClz.isAssignableFrom((Class) pt.getRawType())) {
return pt.getActualTypeArguments();
}
}
}
// check if it if available on generic super class
Type genericSuperclass = classFrom.getGenericSuperclass();
if (genericSuperclass instanceof ParameterizedType) {
ParameterizedType pt = (ParameterizedType) genericSuperclass;
if (interfaceClz.equals(pt.getRawType())) {
return pt.getActualTypeArguments();
}
}
return null;
}
}
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