Java Reflection Generic Parameter getGenericParameter(final Type type)

Description

get Generic Parameter

License

Apache License

Declaration

public static Type[] getGenericParameter(final Type type) 

Method Source Code

//package com.java2s;
/*//from   w w  w.j  a  v  a 2 s .  c  om
 * Copyright 2004-2013 the Seasar Foundation and the Others.
 *
 * 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.
 */

import java.lang.reflect.GenericArrayType;

import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;

public class Main {

    public static Type[] getGenericParameter(final Type type) {
        if (ParameterizedType.class.isInstance(type)) {
            return ParameterizedType.class.cast(type).getActualTypeArguments();
        }
        if (GenericArrayType.class.isInstance(type)) {
            return getGenericParameter(GenericArrayType.class.cast(type).getGenericComponentType());
        }
        return null;
    }

    public static Type getGenericParameter(final Type type, final int index) {
        if (!ParameterizedType.class.isInstance(type)) {
            return null;
        }
        final Type[] genericParameter = getGenericParameter(type);
        if (genericParameter == null) {
            return null;
        }
        return genericParameter[index];
    }
}

Related

1. getGeneric(ParameterizedType type)
2. getGenericParameter(final Type type, final int index)
3. getGenericParameterList(Type type)
4. getGenericParameters(final Type type)
5. getGenericParameterType(Method method, int paramIdx)