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.camel.converter.stream; 018 019import java.io.ByteArrayOutputStream; 020import java.io.IOException; 021import java.io.OutputStream; 022 023import org.apache.camel.Exchange; 024import org.apache.camel.util.ExchangeHelper; 025 026/** 027 * Utility to hide the complexity of choosing which OutputStream 028 * implementation to choose. 029 * <p/> 030 * Itself masquerades as an OutputStream, but really delegates to a 031 * CachedOutputStream of a ByteArrayOutputStream. 032 */ 033public final class OutputStreamBuilder extends OutputStream { 034 035 private final OutputStream outputStream; 036 037 private OutputStreamBuilder(final Exchange exchange) { 038 if (ExchangeHelper.isStreamCachingEnabled(exchange)) { 039 outputStream = new CachedOutputStream(exchange); 040 } else { 041 outputStream = new ByteArrayOutputStream(); 042 } 043 } 044 045 /** 046 * Creates a new OutputStreamBuilder with the current exchange 047 * <p/> 048 * Use the {@link #build()} when writing to the stream is finished, 049 * and you need the result of this operation. 050 * 051 * @param exchange the current Exchange 052 * @return the builder 053 */ 054 public static OutputStreamBuilder withExchange(final Exchange exchange) { 055 return new OutputStreamBuilder(exchange); 056 } 057 058 @Override 059 public void write(final byte[] b, final int off, final int len) throws IOException { 060 outputStream.write(b, off, len); 061 } 062 063 @Override 064 public void write(final byte[] b) throws IOException { 065 outputStream.write(b); 066 } 067 068 @Override 069 public void write(final int b) throws IOException { 070 outputStream.write(b); 071 } 072 073 @Override 074 public void flush() throws IOException { 075 outputStream.flush(); 076 } 077 078 @Override 079 public void close() throws IOException { 080 outputStream.close(); 081 } 082 083 /** 084 * Builds the result of using this builder as either a 085 * {@link org.apache.camel.converter.stream.CachedOutputStream} if stream caching is enabled, 086 * otherwise byte[]. 087 */ 088 public Object build() throws IOException { 089 if (outputStream instanceof CachedOutputStream) { 090 return ((CachedOutputStream)outputStream).newStreamCache(); 091 } 092 return ((ByteArrayOutputStream)outputStream).toByteArray(); 093 } 094}