001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.flatfile.util;
018
019import java.io.BufferedInputStream;
020import java.io.InputStream;
021import java.io.Serializable;
022
023import org.apache.commons.lang3.Validate;
024
025/**
026 * Filter factory designed for use with {@link InputFilteringDynamicField}.
027 * @version $Revision: 1301244 $ $Date: 2012-03-15 17:16:23 -0500 (Thu, 15 Mar 2012) $
028 */
029public abstract class FilterFactory implements Serializable {
030    /** Serialization version */
031    private static final long serialVersionUID = -172092815628700041L;
032
033    /**
034     * Get an InputStream that filters the specified {@link InputStream}
035     * @param is the {@link InputStream} to filter
036     * @return an {@link InputStream}
037     */
038    public final InputStream getFilter(final InputStream is) {
039        return iGetFilter(Validate.notNull(is).markSupported() ? is
040            : new BufferedInputStream(is));
041    }
042
043    /**
044     * Template method to be implemented by subclasses.
045     * @param markIsSupported guaranteed to support mark()/reset().
046     * @return an {@link InputStream}
047     */
048    protected abstract InputStream iGetFilter(InputStream markIsSupported);
049}