util/src/main/java/org/apache/etch/util/cmd/NullOption.java

/* $Id$
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you 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 org.apache.etch.util.cmd;

import org.apache.etch.util.Assertion;

/**
 * An option which has no value.
 */
public class NullOption extends Option
{
	/**
	 * @param cp
	 * @param tokens
	 * @param method
	 * @param description
	 * @param flags
	 * @throws Exception
	 */
	public NullOption( CommandParser cp, String tokens, String method,
		String description, int flags ) throws Exception
	{
		super( cp, tokens, (String[]) null, method, PARAMS, description, flags, null, null );
	}
	
	private final static Class<?>[] PARAMS =
		{ CommandParser.class, Option.class, String.class };
	
	@Override
	public boolean wantsValue()
	{
		return false;
	}

	@Override
	protected Object convertValue( String value )
	{
		throw new UnsupportedOperationException();
	}

	@Override
	protected Object[] getArgs( String token, Object value )
	{
		Assertion.check( value == null, "value == null" );
		return new Object[] { getCommandParser(), this, token };
	}
}