Java Reflection Generic Type from Class getGenericClassByIndex(Type genericType, int index)

Declaration

private static Type getGenericClassByIndex(Type genericType, int index) 

Method Source Code

//package com.java2s;
/*//from   w  w w .j  ava  2 s  .c  o  m
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */

import java.lang.reflect.*;

public class Main {
    /**
     * Get parameterized type
     *
     * @param genericType generic type
     * @param index       index of the target parameterized type
     * @return Return Person.class for List<Person>, return Person.class for Map<String, Person> when index=0
     */
    private static Type getGenericClassByIndex(Type genericType, int index) {
        Type clazz = null;
        // find parameterized type
        if (genericType instanceof ParameterizedType) {
            ParameterizedType t = (ParameterizedType) genericType;
            Type[] types = t.getActualTypeArguments();
            clazz = types[index];
        }
        return clazz;
    }
}

Related

1. getGenericClass(final Method method)
2. getGenericClass(Object o)
3. getGenericClass(Object object, int index)
4. getGenericClass(Object source, ParameterizedType type)
5. getGenericClass(Type type)
6. getGenericClassType(Class clazz, Class filterClass)
7. getGenericDeclaringType(Class baseClass, Class declaringClass)
8. getGenericFirstClass(Type type)
9. getGenericInterface(final Class sourceClass, final Class genericInterface)