ScopedKey.java

/*
 * Copyright (C) 2009 eXo Platform SAS.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */

package org.exoplatform.commons.scope;

import java.io.Serializable;


/**
 * A scoped key wrapping a key including the a scope. The scoped key implements the {@link #hashCode()} and
 * {@link #equals(Object)} method based on the scope and the current value.
 *
 * @author <a href="mailto:julien.viet@exoplatform.com">Julien Viet</a>
 * @version $Revision$
 */
public class ScopedKey<S extends Serializable> extends AbstractScopedKey {

    /**
     * Create a scoped key from a key, the scope value is obtained from the {@link ScopeManager#getCurrentScope()} method.
     *
     * @param key the local key
     * @param <S> the key generic serializable type
     * @return the scoped key
     * @throws NullPointerException if the key argument is null
     */
    public static <S extends Serializable> ScopedKey<S> create(S key) throws NullPointerException {
        return new ScopedKey<S>(key);
    }

    /**
     * Creates a new scoped key with an explicit scope value.
     *
     * @param scope the scope value
     * @param key the key
     * @param <S> the key generic serializable type
     * @return the scoped key
     * @throws NullPointerException if any argument is null
     */
    public static <S extends Serializable> ScopedKey<S> create(String scope, S key) throws NullPointerException {
        return new ScopedKey<S>(scope, key);
    }

    /** . */
    private final S key;

    public ScopedKey(S key) throws NullPointerException {
        if (key == null) {
            throw new NullPointerException();
        }

        //
        this.key = key;
    }

    public ScopedKey(String scope, S key) throws NullPointerException {
        super(scope);

        if (key == null) {
            throw new NullPointerException();
        }

        //
        this.key = key;
    }

    public S getKey() {
        return key;
    }

    @Override
    public int hashCode() {
        return super.hashCode() ^ key.hashCode();
    }

    @Override
    public boolean equals(Object obj) {
        return super.equals(obj) && ((ScopedKey) obj).key.equals(key);
    }

    @Override
    public String toString() {
        return "ScopedKey[scope=" + getScope() + ",key=" + key + "]";
    }
}