michael@0: /*
michael@0:  * ====================================================================
michael@0:  * Licensed to the Apache Software Foundation (ASF) under one
michael@0:  * or more contributor license agreements.  See the NOTICE file
michael@0:  * distributed with this work for additional information
michael@0:  * regarding copyright ownership.  The ASF licenses this file
michael@0:  * to you under the Apache License, Version 2.0 (the
michael@0:  * "License"); you may not use this file except in compliance
michael@0:  * with the License.  You may obtain a copy of the License at
michael@0:  *
michael@0:  *   http://www.apache.org/licenses/LICENSE-2.0
michael@0:  *
michael@0:  * Unless required by applicable law or agreed to in writing,
michael@0:  * software distributed under the License is distributed on an
michael@0:  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
michael@0:  * KIND, either express or implied.  See the License for the
michael@0:  * specific language governing permissions and limitations
michael@0:  * under the License.
michael@0:  * ====================================================================
michael@0:  *
michael@0:  * This software consists of voluntary contributions made by many
michael@0:  * individuals on behalf of the Apache Software Foundation.  For more
michael@0:  * information on the Apache Software Foundation, please see
michael@0:  * <http://www.apache.org/>.
michael@0:  *
michael@0:  */
michael@0: 
michael@0: package ch.boye.httpclientandroidlib.impl.entity;
michael@0: 
michael@0: import java.io.IOException;
michael@0: import java.io.OutputStream;
michael@0: 
michael@0: import ch.boye.httpclientandroidlib.HttpEntity;
michael@0: import ch.boye.httpclientandroidlib.HttpException;
michael@0: import ch.boye.httpclientandroidlib.HttpMessage;
michael@0: import ch.boye.httpclientandroidlib.entity.ContentLengthStrategy;
michael@0: import ch.boye.httpclientandroidlib.impl.io.ChunkedOutputStream;
michael@0: import ch.boye.httpclientandroidlib.impl.io.ContentLengthOutputStream;
michael@0: import ch.boye.httpclientandroidlib.impl.io.IdentityOutputStream;
michael@0: import ch.boye.httpclientandroidlib.io.SessionOutputBuffer;
michael@0: 
michael@0: /**
michael@0:  * HTTP entity serializer.
michael@0:  * <p>
michael@0:  * This entity serializer currently supports "chunked" and "identitiy"
michael@0:  * transfer-coding and content length delimited content.
michael@0:  * <p>
michael@0:  * This class relies on a specific implementation of
michael@0:  * {@link ContentLengthStrategy} to determine the content length or transfer
michael@0:  * encoding of the entity.
michael@0:  * <p>
michael@0:  * This class writes out the content of {@link HttpEntity} to the data stream
michael@0:  * using a transfer coding based on properties on the HTTP message.
michael@0:  *
michael@0:  * @since 4.0
michael@0:  */
michael@0: public class EntitySerializer {
michael@0: 
michael@0:     private final ContentLengthStrategy lenStrategy;
michael@0: 
michael@0:     public EntitySerializer(final ContentLengthStrategy lenStrategy) {
michael@0:         super();
michael@0:         if (lenStrategy == null) {
michael@0:             throw new IllegalArgumentException("Content length strategy may not be null");
michael@0:         }
michael@0:         this.lenStrategy = lenStrategy;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Creates a transfer codec based on properties of the given HTTP message
michael@0:      * and returns {@link OutputStream} instance that transparently encodes
michael@0:      * output data as it is being written out to the output stream.
michael@0:      * <p>
michael@0:      * This method is called by the public
michael@0:      * {@link #serialize(SessionOutputBuffer, HttpMessage, HttpEntity)}.
michael@0:      *
michael@0:      * @param outbuffer the session output buffer.
michael@0:      * @param message the HTTP message.
michael@0:      * @return output stream.
michael@0:      * @throws HttpException in case of HTTP protocol violation.
michael@0:      * @throws IOException in case of an I/O error.
michael@0:      */
michael@0:     protected OutputStream doSerialize(
michael@0:             final SessionOutputBuffer outbuffer,
michael@0:             final HttpMessage message) throws HttpException, IOException {
michael@0:         long len = this.lenStrategy.determineLength(message);
michael@0:         if (len == ContentLengthStrategy.CHUNKED) {
michael@0:             return new ChunkedOutputStream(outbuffer);
michael@0:         } else if (len == ContentLengthStrategy.IDENTITY) {
michael@0:             return new IdentityOutputStream(outbuffer);
michael@0:         } else {
michael@0:             return new ContentLengthOutputStream(outbuffer, len);
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Writes out the content of the given HTTP entity to the session output
michael@0:      * buffer based on properties of the given HTTP message.
michael@0:      *
michael@0:      * @param outbuffer the output session buffer.
michael@0:      * @param message the HTTP message.
michael@0:      * @param entity the HTTP entity to be written out.
michael@0:      * @throws HttpException in case of HTTP protocol violation.
michael@0:      * @throws IOException in case of an I/O error.
michael@0:      */
michael@0:     public void serialize(
michael@0:             final SessionOutputBuffer outbuffer,
michael@0:             final HttpMessage message,
michael@0:             final HttpEntity entity) throws HttpException, IOException {
michael@0:         if (outbuffer == null) {
michael@0:             throw new IllegalArgumentException("Session output buffer may not be null");
michael@0:         }
michael@0:         if (message == null) {
michael@0:             throw new IllegalArgumentException("HTTP message may not be null");
michael@0:         }
michael@0:         if (entity == null) {
michael@0:             throw new IllegalArgumentException("HTTP entity may not be null");
michael@0:         }
michael@0:         OutputStream outstream = doSerialize(outbuffer, message);
michael@0:         entity.writeTo(outstream);
michael@0:         outstream.close();
michael@0:     }
michael@0: 
michael@0: }