/*

 * Copyright (c) 2013, 2016, Oracle and/or its affiliates. All rights reserved.

 * 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

 * questions.

 */

package java.beans;

import java.lang.ref.SoftReference;

import java.lang.ref.WeakReference;

import java.lang.reflect.Method;

import static sun.reflect.misc.ReflectUtil.isPackageAccessible;

final class MethodRef {

    private String signature;

    private SoftReference<Method> methodRef;

    private WeakReference<Class<?>> typeRef;

    void set(Method method) {

        if (method == null) {

            this.signature = null;

            this.methodRef = null;

            this.typeRef = null;

        }

        else {

            this.signature = method.toGenericString();

            this.methodRef = new SoftReference<>(method);

            this.typeRef = new WeakReference<Class<?>>(method.getDeclaringClass());

        }

    }

    boolean isSet() {

        return this.methodRef != null;

    }

    Method get() {

        if (this.methodRef == null) {

            return null;

        }

        Method method = this.methodRef.get();

        if (method == null) {

            method = find(this.typeRef.get(), this.signature);

            if (method == null) {

                this.signature = null;

                this.methodRef = null;

                this.typeRef = null;

                return null;

            }

            this.methodRef = new SoftReference<>(method);

        }

        return isPackageAccessible(method.getDeclaringClass()) ? method : null;

    }

    private static Method find(Class<?> type, String signature) {

        if (type != null) {

            for (Method method : type.getMethods()) {

                if (type.equals(method.getDeclaringClass())) {

                    if (method.toGenericString().equals(signature)) {

                        return method;

                    }

                }

            }

        }

        return null;

    }

}