Java Reflection Assignable isAssignableFrom(Class to, Class from)

Description

Improves java5's Class.isAssignableFrom method.

License

Apache License

Parameter

Parameter	Description
to	The class one.
from	The class two.

Return

Returns true if to is assignable from from .

Declaration

public static boolean isAssignableFrom(Class<?> to, Class<?> from) 

Method Source Code

//package com.java2s;
/*//  w  w w . j av  a 2 s  . co  m
 * Copyright 2009 Grepo Committers.
 *
 * 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.util.HashMap;
import java.util.Map;

public class Main {
    /**
     * Map of all nine java-primitives and their associated wrapper objects.
     */
    private static final Map<Class<?>, Class<?>> PRIMITIVE_TO_WRAPPER = new HashMap<Class<?>, Class<?>>();

    /**
     * Improves java5's {@code Class.isAssignableFrom} method.
     * This method returns false for primitives and their wrapper objects
     * (which is not really correct, because of auto-boxing).
     *
     * @param to The class one.
     * @param from The class two.
     * @return Returns true if {@code to} is assignable from {@code from}.
     */
    public static boolean isAssignableFrom(Class<?> to, Class<?> from) {
        if (PRIMITIVE_TO_WRAPPER.get(to) == from || PRIMITIVE_TO_WRAPPER.get(from) == to) {
            return true;
        }
        return to.isAssignableFrom(from);
    }
}

Related

1. isAssignable(Class lhsType, Class rhsType)
2. isAssignable(Class lhsType, Class rhsType)
3. isAssignable(Class lhsType, Class rhsType)
4. isAssignable(final Class from, final Class to)
5. isAssignableFrom(Class class1, Class class2)
6. isAssignableFrom(Class to, Class from)
7. isAssignableFrom(Class toClass, Class fromClass)
8. isAssignableValue(Class type, Object value)
9. isAssignableValue(Class type, Object value)