com.link_intersystems.lang.reflect.MemberModifierPredicate.java Source code

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Here is the source code for com.link_intersystems.lang.reflect.MemberModifierPredicate.java

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/**
 * Copyright 2011 Link Intersystems GmbH <rene.link@link-intersystems.com>
 *
 * 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.
 */
package com.link_intersystems.lang.reflect;

import java.io.Serializable;
import java.lang.reflect.Member;

import org.apache.commons.collections4.Predicate;

import com.link_intersystems.lang.Assert;

/**
 * A {@link Predicate} that evaluates {@link Member}'s modifiers. See
 * {@link #evaluate(Object)} for details.
 *
 * @author Ren Link <a
 *         href="mailto:rene.link@link-intersystems.com">[rene.link@link-
 *         intersystems.com]</a>
 * @since 1.0.0.0
 */
public class MemberModifierPredicate implements Predicate<Member>, Serializable {

    /**
     *
     */
    private static final long serialVersionUID = 8409323272367693837L;

    private final int modifiers;

    private Match match;

    /**
     * The {@link Match} type that the {@link MemberModifierPredicate} uses.
     *
     * @author Ren Link <a
     *         href="mailto:rene.link@link-intersystems.com">[rene.link@link-
     *         intersystems.com]</a>
     * @since 1.0.0.0
     */
    public enum Match {
        /**
         * Exact modifier match. E.g. {@link Member#getModifiers()} ==
         * definedModifiers.
         *
         * @since 1.0.0.0
         */
        EXACT,
        /**
         * At least one modifier must match. If the {@link Member}'s modifiers
         * are public static final and the modifiers compared to are final it
         * matches.
         *
         * @since 1.0.0.0
         */
        AT_LEAST_ONE,
        /**
         * At least all modifier must match. If the {@link Member}'s modifiers
         * are public abstract and the modifiers compared to are public it
         * matches. In contrast to {@link #EXACT} this {@link Match} type does
         * not enforce that all modifiers must match. It only defines that the
         * modifiers compared to must all match.
         *
         * @since 1.0.0.0
         */
        AT_LEAST_ALL
    }

    /**
     * Constructs a {@link MemberModifierPredicate} that maches the defined
     * modifers with {@link Match} type {@link Match#AT_LEAST_ALL};
     *
     * @param modifiers
     * @since 1.0.0.0
     */
    public MemberModifierPredicate(int modifiers) {
        this(modifiers, Match.AT_LEAST_ALL);
    }

    /**
     * Constructs a {@link MemberModifierPredicate} that maches the defined
     * modifers with the given {@link Match} type.
     *
     * @param modifiers
     * @since 1.0.0.0
     */
    public MemberModifierPredicate(int modifiers, Match match) {
        Assert.notNull("match", match);
        this.modifiers = modifiers;
        this.match = match;
    }

    /**
     * {@inheritDoc}
     *
     * @return true if the object evaluated against is a {@link Member} and that
     *         {@link Member}s modifiers match the modifiers that this
     *         {@link MemberModifierPredicate} was constructed with according to
     *         the {@link Match} type.
     * @param object
     *            must be a {@link Member}.
     * @since 1.0.0.0
     * @throws IllegalArgumentException
     *             if the object this {@link Predicate} is evaluated against is
     *             not a {@link Member}.
     */
    public boolean evaluate(Member object) {
        Member member = (Member) object;
        int modifiers = member.getModifiers();
        if (match.equals(Match.EXACT)) {
            return this.modifiers == modifiers;
        } else if (match.equals(Match.AT_LEAST_ONE)) {
            return (modifiers & this.modifiers) != 0;
        } else {
            return (modifiers & this.modifiers) == this.modifiers;
        }
    }

}