patterntesting.runtime.NullConstants Maven / Gradle / Ivy
/**
* $Id: NullConstants.java,v 1.2 2012/07/16 19:57:11 oboehm Exp $
*
* Copyright (c) 2009 by Oliver Boehm
*
* 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 orimplied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* (c)reated 13.06.2009 by oliver ([email protected])
*/
package patterntesting.runtime;
import java.io.File;
import java.util.Date;
/**
* This class contains some constants (like a NULL_STRING) as constant.
* It can be statically imported.
*
* @author oliver
* @since 13.06.2009
* @version $Revision: 1.2 $
*/
public final class NullConstants {
/** to avoid that this class will be instantiated */
private NullConstants() {}
/**
* If you have a method with a list of arguments where some arguments are
* optional you can
*
* -
* provide the method with different signatures
* (good idea, but not always feasible)
*
* -
* admit null arguments and handle it in the methode
* (not a good idea because it can happen accidentally)
*
* -
* use this special NULL_OBJECT object to mark an argument as optional
*
*
* Unfortunately this works only for object as argument. For String as
* argument you can use NULL_STRING.
*
* @see #NULL_STRING
*/
public static final Object NULL_OBJECT = new Object();
/**
* You need a null string and don't want to use null? Use
* NULL_STRING and you can write code like
*
* if (name == NULL_STRING) ...
*
*/
public static final String NULL_STRING = "";
/**
* You need a null file and don't want to use null? Use
* NULL_FILE and you can write code like
*
* if (name == NULL_STRING) ...
*
*/
public static final File NULL_FILE = new File(NULL_STRING);
/**
* You need a null throwable and don't want to use null? Use
* NULL_THROWABLE and you can write code like
*
* if (name == NULL_THROWABLE) ...
*
*/
public static final Throwable NULL_THROWABLE = new Throwable();
/**
* You need a null exception and don't want to use null? Use
* NULL_EXCEPTION and you can write code like
*
* if (name == NULL_EXCEPTION) ...
*
*/
public static final Throwable NULL_EXCEPTION = new Exception();
/**
* You need a null date and don't want to use null? Use
* NULL_DATE and you can write code like
*
* if (name == NULL_DATE) ...
*
* The NULL_DATE is defined here as 1.1.1970 (the epoch).
*/
public static final Date NULL_DATE = new Date(0L);
}