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.ByteArrayInputStream;
020 import java.io.ByteArrayOutputStream;
021 import java.io.IOException;
022 import java.io.InputStream;
023 import java.io.Reader;
024 import java.io.Serializable;
025 import javax.xml.transform.TransformerException;
026 import javax.xml.transform.sax.SAXSource;
027 import javax.xml.transform.stream.StreamSource;
028
029 import org.apache.camel.BytesSource;
030 import org.apache.camel.Converter;
031 import org.apache.camel.Exchange;
032 import org.apache.camel.StreamCache;
033 import org.apache.camel.StringSource;
034 import org.apache.camel.util.IOHelper;
035
036 /**
037 * A set of {@link Converter} methods for wrapping stream-based messages in a {@link StreamCache}
038 * implementation to ensure message re-readability (eg multicasting, retrying)
039 */
040 @Converter
041 public final class StreamCacheConverter {
042
043 /**
044 * Utility classes should not have a public constructor.
045 */
046 private StreamCacheConverter() {
047 }
048
049 @Converter
050 public static StreamCache convertToStreamCache(StreamSource source, Exchange exchange) throws IOException {
051 return new StreamSourceCache(source, exchange);
052 }
053
054 @Converter
055 public static StreamCache convertToStreamCache(StringSource source) {
056 //no need to do stream caching for a StringSource
057 return null;
058 }
059
060 @Converter
061 public static StreamCache convertToStreamCache(BytesSource source) {
062 //no need to do stream caching for a BytesSource
063 return null;
064 }
065
066 @Converter
067 public static StreamCache convertToStreamCache(SAXSource source, Exchange exchange) throws TransformerException {
068 String data = exchange.getContext().getTypeConverter().convertTo(String.class, exchange, source);
069 return new SourceCache(data);
070 }
071
072 @Converter
073 public static StreamCache convertToStreamCache(ByteArrayInputStream stream, Exchange exchange) throws IOException {
074 return new ByteArrayInputStreamCache(stream);
075 }
076
077 @Converter
078 public static StreamCache convertToStreamCache(InputStream stream, Exchange exchange) throws IOException {
079 // transfer the input stream to a cached output stream, and then creates a new stream cache view
080 // of the data, which ensures the input stream is cached and re-readable.
081 CachedOutputStream cos = new CachedOutputStream(exchange);
082 IOHelper.copyAndCloseInput(stream, cos);
083 return cos.newStreamCache();
084 }
085
086 @Converter
087 public static StreamCache convertToStreamCache(Reader reader, Exchange exchange) throws IOException {
088 String data = exchange.getContext().getTypeConverter().convertTo(String.class, exchange, reader);
089 return new ReaderCache(data);
090 }
091
092 @Converter
093 public static Serializable convertToSerializable(StreamCache cache, Exchange exchange) throws IOException {
094 byte[] data = convertToByteArray(cache, exchange);
095 return new BytesSource(data);
096 }
097
098 @Converter
099 public static byte[] convertToByteArray(StreamCache cache, Exchange exchange) throws IOException {
100 // lets serialize it as a byte array
101 ByteArrayOutputStream os = new ByteArrayOutputStream();
102 cache.writeTo(os);
103 return os.toByteArray();
104 }
105
106 }