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.ByteArrayOutputStream;
020    import java.io.IOException;
021    import java.io.InputStream;
022    import java.io.Reader;
023    import java.io.Serializable;
024    import javax.xml.transform.TransformerException;
025    import javax.xml.transform.sax.SAXSource;
026    import javax.xml.transform.stream.StreamSource;
027    
028    import org.apache.camel.Converter;
029    import org.apache.camel.Exchange;
030    import org.apache.camel.StreamCache;
031    import org.apache.camel.converter.jaxp.BytesSource;
032    import org.apache.camel.converter.jaxp.StringSource;
033    import org.apache.camel.util.IOHelper;
034    
035    /**
036     * A set of {@link Converter} methods for wrapping stream-based messages in a {@link StreamCache}
037     * implementation to ensure message re-readability (eg multicasting, retrying)
038     */
039    @Converter
040    public class StreamCacheConverter {
041    
042        @Converter
043        public StreamCache convertToStreamCache(StreamSource source, Exchange exchange) throws IOException {
044            return new StreamSourceCache(source, exchange);
045        }
046    
047        @Converter
048        public StreamCache convertToStreamCache(StringSource source) {
049            //no need to do stream caching for a StringSource
050            return null;
051        }
052    
053        @Converter
054        public StreamCache convertToStreamCache(BytesSource source) {
055            //no need to do stream caching for a BytesSource
056            return null;
057        }
058    
059        @Converter
060        public StreamCache convertToStreamCache(SAXSource source, Exchange exchange) throws TransformerException {
061            String data = exchange.getContext().getTypeConverter().convertTo(String.class, source);
062            return new SourceCache(data);
063        }
064    
065        @Converter
066        public StreamCache convertToStreamCache(InputStream stream, Exchange exchange) throws IOException {
067            CachedOutputStream cos = new CachedOutputStream(exchange);
068            IOHelper.copyAndCloseInput(stream, cos);
069            return cos.getStreamCache();
070        }
071    
072        @Converter
073        public StreamCache convertToStreamCache(Reader reader, Exchange exchange) throws IOException {
074            String data = exchange.getContext().getTypeConverter().convertTo(String.class, reader);
075            return new ReaderCache(data);
076        }
077    
078        @Converter
079        public Serializable convertToSerializable(StreamCache cache, Exchange exchange) throws IOException {
080            byte[] data = convertToByteArray(cache, exchange);
081            return new BytesSource(data);
082        }
083    
084        @Converter
085        public byte[] convertToByteArray(StreamCache cache, Exchange exchange) throws IOException {
086            // lets serialize it as a byte array
087            ByteArrayOutputStream os = new ByteArrayOutputStream();
088            cache.writeTo(os);
089            return os.toByteArray();
090        }
091    
092    }