/*
* Copyright (c) 2002-2012 Alibaba Group Holding Limited.
* All rights reserved.
*
* 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.alibaba.citrus.generictype;
import static com.alibaba.citrus.generictype.TypeInfo.*;
import static com.alibaba.citrus.util.Assert.*;
import java.util.Iterator;
import java.util.Map;
/**
* 方便使用{@link TypeInfo}的工具。
*
* @author Michael Zhou
*/
public class TypeInfoUtil {
public final static TypeInfo TYPE_VAR_MAP_KEY = factory.getType(Map.class.getTypeParameters()[0]);
public final static TypeInfo TYPE_VAR_MAP_VALUE = factory.getType(Map.class.getTypeParameters()[1]);
public final static TypeInfo TYPE_VAR_ITERABLE_ELEMENT = factory.getType(Iterable.class.getTypeParameters()[0]);
public final static TypeInfo TYPE_VAR_ITERATOR_ELEMENT = factory.getType(Iterator.class.getTypeParameters()[0]);
/**
* 取得指定类型的实际参数。
* <p>
* 例如：<code>class MyClass extends BaseClass<Integer></code>，那么调用：
* <code>resolveParameter(MyClass.class, BaseClass.class, 0)</code>将返回
* <code>Integer</code>。
* </p>
*/
public static TypeInfo resolveParameter(Class<?> contextClass, Class<?> parentClass, int index) {
assertNotNull(contextClass, "contextClass");
assertNotNull(parentClass, "parentClass");
assertTrue(index < parentClass.getTypeParameters().length, "index out of bound");
GenericDeclarationInfo context = factory.getGenericDeclaration(contextClass);
TypeInfo param = factory.getType(parentClass.getTypeParameters()[index]);
return param.resolve(context);
}
/** 取得{@link Map}的key类型。 */
public static TypeInfo resolveMapKey(Class<?> mapClass) {
return resolveMapKey(factory.getClassType(mapClass));
}
/** 取得{@link Map}的key类型。 */
public static TypeInfo resolveMapKey(TypeInfo mapType) {
assertTrue(
mapType != null && mapType instanceof ClassTypeInfo && Map.class.isAssignableFrom(mapType.getRawType()),
"mapType: %s", mapType);
return TYPE_VAR_MAP_KEY.resolve((ClassTypeInfo) mapType);
}
/** 取得{@link Map}的value类型。 */
public static TypeInfo resolveMapValue(Class<?> mapClass) {
return resolveMapValue(factory.getClassType(mapClass));
}
/** 取得{@link Map}的value类型。 */
public static TypeInfo resolveMapValue(TypeInfo mapType) {
assertTrue(
mapType != null && mapType instanceof ClassTypeInfo && Map.class.isAssignableFrom(mapType.getRawType()),
"mapType: %s", mapType);
return TYPE_VAR_MAP_VALUE.resolve((ClassTypeInfo) mapType);
}
/** 取得{@link Iterable}的element类型。 */
public static TypeInfo resolveIterableElement(Class<?> iterableClass) {
return resolveIterableElement(factory.getClassType(iterableClass));
}
/** 取得{@link Iterable}的element类型。 */
public static TypeInfo resolveIterableElement(TypeInfo iterableType) {
assertTrue(
iterableType != null && iterableType instanceof ClassTypeInfo
&& Iterable.class.isAssignableFrom(iterableType.getRawType()), "iterableType: %s", iterableType);
return TYPE_VAR_ITERABLE_ELEMENT.resolve((ClassTypeInfo) iterableType);
}
/** 取得{@link Iterator}的element类型。 */
public static TypeInfo resolveIteratorElement(Class<?> iteratorClass) {
return resolveIteratorElement(factory.getClassType(iteratorClass));
}
/** 取得{@link Iterator}的element类型。 */
public static TypeInfo resolveIteratorElement(TypeInfo iteratorType) {
assertTrue(
iteratorType != null && iteratorType instanceof ClassTypeInfo
&& Iterator.class.isAssignableFrom(iteratorType.getRawType()), "iteratorType: %s", iteratorType);
return TYPE_VAR_ITERATOR_ELEMENT.resolve((ClassTypeInfo) iteratorType);
}
}