/*
* $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpcore/tags/4.0/module-main/src/main/java/org/apache/http/impl/entity/EntitySerializer.java $
* $Revision: 744526 $
* $Date: 2009-02-14 18:04:18 +0100 (Sat, 14 Feb 2009) $
*
* ====================================================================
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.http.impl.entity;
import java.io.IOException;
import java.io.OutputStream;
import org.apache.http.HttpEntity;
import org.apache.http.HttpException;
import org.apache.http.HttpMessage;
import org.apache.http.entity.ContentLengthStrategy;
import org.apache.http.impl.io.ChunkedOutputStream;
import org.apache.http.impl.io.ContentLengthOutputStream;
import org.apache.http.impl.io.IdentityOutputStream;
import org.apache.http.io.SessionOutputBuffer;
/**
* HTTP entity serializer.
* <p>
* This entity serializer currently supports "chunked" and "identitiy"
* transfer-coding and content length delimited content.
* <p>
* This class relies on a specific implementation of
* {@link ContentLengthStrategy} to determine the content length or transfer
* encoding of the entity.
* <p>
* This class writes out the content of {@link HttpEntity} to the data stream
* using a transfer coding based on properties on the HTTP message.
*
*
* @version $Revision: 744526 $
*
* @since 4.0
*/
public class EntitySerializer {
private final ContentLengthStrategy lenStrategy;
public EntitySerializer(final ContentLengthStrategy lenStrategy) {
super();
if (lenStrategy == null) {
throw new IllegalArgumentException("Content length strategy may not be null");
}
this.lenStrategy = lenStrategy;
}
/**
* Creates a transfer codec based on properties of the given HTTP message
* and returns {@link OutputStream} instance that transparently encodes
* output data as it is being written out to the output stream.
* <p>
* This method is called by the public
* {@link #serialize(SessionOutputBuffer, HttpMessage, HttpEntity)}.
*
* @param outbuffer the session output buffer.
* @param message the HTTP message.
* @return output stream.
* @throws HttpException in case of HTTP protocol violation.
* @throws IOException in case of an I/O error.
*/
protected OutputStream doSerialize(
final SessionOutputBuffer outbuffer,
final HttpMessage message) throws HttpException, IOException {
long len = this.lenStrategy.determineLength(message);
if (len == ContentLengthStrategy.CHUNKED) {
return new ChunkedOutputStream(outbuffer);
} else if (len == ContentLengthStrategy.IDENTITY) {
return new IdentityOutputStream(outbuffer);
} else {
return new ContentLengthOutputStream(outbuffer, len);
}
}
/**
* Writes out the content of the given HTTP entity to the session output
* buffer based on properties of the given HTTP message.
*
* @param outbuffer the output session buffer.
* @param message the HTTP message.
* @param entity the HTTP entity to be written out.
* @throws HttpException in case of HTTP protocol violation.
* @throws IOException in case of an I/O error.
*/
public void serialize(
final SessionOutputBuffer outbuffer,
final HttpMessage message,
final HttpEntity entity) throws HttpException, IOException {
if (outbuffer == null) {
throw new IllegalArgumentException("Session output buffer may not be null");
}
if (message == null) {
throw new IllegalArgumentException("HTTP message may not be null");
}
if (entity == null) {
throw new IllegalArgumentException("HTTP entity may not be null");
}
OutputStream outstream = doSerialize(outbuffer, message);
entity.writeTo(outstream);
outstream.close();
}
}