package org.apache.ojb.jdo.jdoql;
/* Copyright 2003-2005 The Apache Software Foundation
*
* 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.
*/
/**
* The 'null' literal.
*
* @author <a href="mailto:tomdz@apache.org">Thomas Dudziak</a>
*/
public class NullLiteral extends Expression
{
/** The type of this null literal */
private Class _type = Object.class;
/**
* Creates a new null literal object.
*/
public NullLiteral()
{
}
/* (non-Javadoc)
* @see org.apache.ojb.jdo.jdoql.Acceptor#accept(org.apache.ojb.jdo.jdoql.Visitor)
*/
public void accept(Visitor visitor)
{
visitor.visit(this);
}
/* (non-Javadoc)
* @see java.lang.Object#toString()
*/
public String toString()
{
return "null";
}
/**
* Sets the type of this null literal. The type depends on the context
* of the literal, e.g. in a binary expression where the other side
* is of type string, this literal would also have type string.
*
* @param type The type
*/
public void setType(Class type)
{
_type = type;
}
/* (non-Javadoc)
* @see org.apache.ojb.jdo.jdoql.Expression#getType()
*/
public Class getType()
{
return _type;
}
}
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