/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

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 */

package com.sun.beans.finder;

import com.sun.beans.WeakCache;

import java.lang.reflect.Constructor;

import java.lang.reflect.Modifier;

/**

 * This utility class provides {@code static} methods

 * to find a public constructor with specified parameter types

 * in specified class.

 *

 * @since 1.7

 *

 * @author Sergey A. Malenkov

 */

public final class ConstructorFinder extends AbstractFinder<Constructor<?>> {

    private static final WeakCache<Signature, Constructor<?>> CACHE = new WeakCache<Signature, Constructor<?>>();

    /**

     * Finds public constructor

     * that is declared in public class.

     *

     * @param type  the class that can have constructor

     * @param args  parameter types that is used to find constructor

     * @return object that represents found constructor

     * @throws NoSuchMethodException if constructor could not be found

     *                               or some constructors are found

     */

    public static Constructor<?> findConstructor(Class<?> type, Class<?>...args) throws NoSuchMethodException {

        if (type.isPrimitive()) {

            throw new NoSuchMethodException("Primitive wrapper does not contain constructors");

        }

        if (type.isInterface()) {

            throw new NoSuchMethodException("Interface does not contain constructors");

        }

        if (Modifier.isAbstract(type.getModifiers())) {

            throw new NoSuchMethodException("Abstract class cannot be instantiated");

        }

            throw new NoSuchMethodException("Class is not accessible");

        }

        PrimitiveWrapperMap.replacePrimitivesWithWrappers(args);

        Signature signature = new Signature(type, args);

        Constructor<?> constructor = CACHE.get(signature);

        if (constructor != null) {

            return constructor;

        }

        constructor = new ConstructorFinder(args).find(type.getConstructors());

        CACHE.put(signature, constructor);

        return constructor;

    }

    /**

     * Creates constructor finder with specified array of parameter types.

     *

     * @param args  the array of parameter types

     */

    private ConstructorFinder(Class<?>[] args) {

        super(args);

    }

    /**

     * Returns an array of {@code Class} objects

     * that represent the formal parameter types of the constructor.

     * Returns an empty array if the constructor takes no parameters.

     *

     * @param constructor  the object that represents constructor

     * @return the parameter types of the constructor

     */

    @Override

    protected Class<?>[] getParameters(Constructor<?> constructor) {

        return constructor.getParameterTypes();

    }

    /**

     * Returns {@code true} if and only if the constructor

     * was declared to take a variable number of arguments.

     *

     * @param constructor  the object that represents constructor

     * @return {@code true} if the constructor was declared

     *         to take a variable number of arguments;

     *         {@code false} otherwise

     */

    @Override

    protected boolean isVarArgs(Constructor<?> constructor) {

        return constructor.isVarArgs();

    }

    /**

     * Checks validness of the constructor.

     * The valid constructor should be public.

     *

     * @param constructor  the object that represents constructor

     * @return {@code true} if the constructor is valid,

     *         {@code false} otherwise

     */

    @Override

    protected boolean isValid(Constructor<?> constructor) {

        return Modifier.isPublic(constructor.getModifiers());

    }

}