/* $Id$ */
/**
* 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.manifoldcf.core.interfaces;
import java.io.*;
import org.apache.manifoldcf.core.system.ManifoldCF;
/** This class represents a null character stream, which has no characters.
*/
public class NullCharacterInput extends CharacterInput
{
public static final String _rcsid = "@(#)$Id$";
/** Construct from nothing.
*/
public NullCharacterInput()
{
super();
}
@Override
public Reader getStream()
throws ManifoldCFException
{
return new StringReader("");
}
@Override
public void doneWithStream()
throws ManifoldCFException
{
}
@Override
public long getCharacterLength()
throws ManifoldCFException
{
return 0L;
}
@Override
public String getHashValue()
throws ManifoldCFException
{
return ManifoldCF.getHashValue(ManifoldCF.startHash());
}
/** Open a Utf8 stream directly */
@Override
public InputStream getUtf8Stream()
throws ManifoldCFException
{
return new ByteArrayInputStream(new byte[]{});
}
/** Get binary UTF8 stream length directly */
@Override
public long getUtf8StreamLength()
throws ManifoldCFException
{
return 0L;
}
/** Transfer to a new object; this causes the current object to become "already discarded" */
@Override
public CharacterInput transfer()
{
return new NullCharacterInput();
}
/** Discard this object permanently */
@Override
public void discard()
throws ManifoldCFException
{
}
// Protected methods
/** Open a reader, for use by a caller, until closeStream is called */
@Override
protected void openStream()
throws ManifoldCFException
{
}
/** Close any open reader */
@Override
protected void closeStream()
throws ManifoldCFException
{
}
/** Calculate the datum's length in characters */
@Override
protected void calculateLength()
throws ManifoldCFException
{
}
/** Calculate the datum's hash value */
@Override
protected void calculateHashValue()
throws ManifoldCFException
{
}
}