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     */
017    package org.apache.camel.converter.stream;
018    
019    import java.io.File;
020    import java.io.FileInputStream;
021    import java.io.FileNotFoundException;
022    import java.io.IOException;
023    import java.io.InputStream;
024    import java.io.OutputStream;
025    
026    import org.apache.camel.RuntimeCamelException;
027    import org.apache.camel.StreamCache;
028    import org.apache.camel.util.IOHelper;
029    
030    public class FileInputStreamCache extends InputStream implements StreamCache {
031        private InputStream stream;
032        private CachedOutputStream cachedOutputStream;
033        private File file;
034    
035        public FileInputStreamCache() {
036        }
037    
038        public FileInputStreamCache(File file, CachedOutputStream cos) throws FileNotFoundException {
039            this.file = file;
040            this.cachedOutputStream = cos;
041            this.stream = new FileInputStream(file);
042        }
043        
044        @Override
045        public void close() {
046            try {
047                getInputStream().close();
048                if (cachedOutputStream != null) {
049                    cachedOutputStream.close();
050                }
051            } catch (Exception e) {
052                throw new RuntimeCamelException(e);
053            } 
054        }
055    
056        @Override
057        public void reset() {
058            try {
059                getInputStream().close();
060                // reset by creating a new stream based on the file
061                stream = new FileInputStream(file);
062            } catch (Exception e) {
063                throw new RuntimeCamelException(e);
064            }            
065        }
066    
067        public void writeTo(OutputStream os) throws IOException {
068            IOHelper.copy(getInputStream(), os);
069        }
070    
071        @Override
072        public int available() throws IOException {
073            return getInputStream().available();
074        }
075    
076        @Override
077        public int read() throws IOException {
078            return getInputStream().read();
079        }
080    
081        protected InputStream getInputStream() throws FileNotFoundException {
082            if (file != null && stream == null) {
083                stream = new FileInputStream(file);
084            }
085            return stream;
086        }
087    
088    }