/*
* Copyright 2009 Red Hat, Inc.
*
* Red Hat 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.
*/
package org.jboss.netty.handler.codec.http;
import static org.jboss.netty.buffer.ChannelBuffers.*;
import static org.jboss.netty.handler.codec.http.HttpCodecUtil.*;
import java.io.UnsupportedEncodingException;
import java.util.List;
import java.util.Set;
import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.buffer.ChannelBuffers;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.ChannelPipelineCoverage;
import org.jboss.netty.handler.codec.oneone.OneToOneEncoder;
import org.jboss.netty.util.CharsetUtil;
/**
* Encodes an {@link HttpMessage} or an {@link HttpChunk} into
* a {@link ChannelBuffer}.
*
*
Extensibility
*
* Please note that this encoder is designed to be extended to implement
* a protocol derived from HTTP, such as
* RTSP and
* ICAP.
* To implement the encoder of such a derived protocol, extend this class and
* implement all abstract methods properly.
*
* @author The Netty Project (netty-dev@lists.jboss.org)
* @author Andy Taylor (andy.taylor@jboss.org)
* @author Trustin Lee (trustin@gmail.com)
* @version $Rev$, $Date$
*
* @apiviz.landmark
*/
@ChannelPipelineCoverage("one")
public abstract class HttpMessageEncoder extends OneToOneEncoder {
private static final ChannelBuffer LAST_CHUNK =
copiedBuffer("0\r\n\r\n", CharsetUtil.US_ASCII);
private volatile boolean chunked;
/**
* Creates a new instance.
*/
protected HttpMessageEncoder() {
super();
}
@Override
protected Object encode(ChannelHandlerContext ctx, Channel channel, Object msg) throws Exception {
if (msg instanceof HttpMessage) {
HttpMessage m = (HttpMessage) msg;
boolean chunked = this.chunked = HttpCodecUtil.isTransferEncodingChunked(m);
ChannelBuffer header = ChannelBuffers.dynamicBuffer(
channel.getConfig().getBufferFactory());
encodeInitialLine(header, m);
encodeHeaders(header, m);
header.writeBytes(CRLF);
ChannelBuffer content = m.getContent();
if (!content.readable()) {
return header; // no content
} else if (chunked) {
throw new IllegalArgumentException(
"HttpMessage.content must be empty " +
"if Transfer-Encoding is chunked.");
} else {
return wrappedBuffer(header, content);
}
}
if (msg instanceof HttpChunk) {
HttpChunk chunk = (HttpChunk) msg;
if (chunked) {
if (chunk == HttpChunk.LAST_CHUNK) {
chunked = false;
return LAST_CHUNK.duplicate();
} else if (chunk instanceof HttpChunkTrailer) {
ChannelBuffer trailer = ChannelBuffers.dynamicBuffer(
channel.getConfig().getBufferFactory());
trailer.writeByte((byte) '0');
trailer.writeBytes(CRLF);
encodeTrailingHeaders(trailer, (HttpChunkTrailer) chunk);
trailer.writeBytes(CRLF);
return trailer;
} else {
ChannelBuffer content = chunk.getContent();
int contentLength = content.readableBytes();
return wrappedBuffer(
copiedBuffer(
Integer.toHexString(contentLength),
CharsetUtil.US_ASCII),
wrappedBuffer(CRLF),
content.slice(content.readerIndex(), contentLength),
wrappedBuffer(CRLF));
}
} else {
if (chunk == HttpChunk.LAST_CHUNK) {
return null;
} else {
return chunk.getContent();
}
}
}
// Unknown message type.
return msg;
}
private void encodeHeaders(ChannelBuffer buf, HttpMessage message) {
Set headers = message.getHeaderNames();
try {
for (String header : headers) {
List values = message.getHeaders(header);
for (String value : values) {
encodeHeader(buf, header, value);
}
}
} catch (UnsupportedEncodingException e) {
throw (Error) new Error().initCause(e);
}
}
private void encodeTrailingHeaders(ChannelBuffer buf, HttpChunkTrailer trailer) {
Set headers = trailer.getHeaderNames();
try {
for (String header : headers) {
List values = trailer.getHeaders(header);
for (String value : values) {
encodeHeader(buf, header, value);
}
}
} catch (UnsupportedEncodingException e) {
throw (Error) new Error().initCause(e);
}
}
private void encodeHeader(ChannelBuffer buf, String header, String value)
throws UnsupportedEncodingException {
buf.writeBytes(header.getBytes("ASCII"));
buf.writeByte(COLON);
buf.writeByte(SP);
buf.writeBytes(value.getBytes("ASCII"));
buf.writeBytes(CRLF);
}
protected abstract void encodeInitialLine(ChannelBuffer buf, HttpMessage message) throws Exception;
}