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/*
* This program is free software; you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
* Foundation.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
* or from the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* This program 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.
*
* Copyright (c) 2007 - 2009 Pentaho Corporation and Contributors. All rights reserved.
*/
package org.pentaho.reporting.libraries.base.util;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* Class which holds a static reference to a set of empty objects. This is created for performance
* reasons. Using this class will prevent creating duplicated "empty" object.
*
* @author David Kincade
*/
public final class Empty {
/**
* No reason to create an instance of this class.
*/
private Empty() {
}
/**
* The empty string.
*/
public static final String STRING = "";
/**
* An empty array of Strings.
*/
public static final String[] STRING_ARRAY = new String[0];
/**
* An empty Map. (Collections.EMPTY_MAP is not available until JDK 1.4)
* @noinspection PublicStaticCollectionField
*/
public static final Map MAP = Collections.unmodifiableMap(new HashMap());
/**
* An empty List.
*
* @deprecated this is a redeclaration of the Collections.EMPTY_LIST field and should be killed.
* @noinspection PublicStaticCollectionField
*/
public static final List LIST = Collections.EMPTY_LIST;
}
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