io.netty.handler.codec.http.HttpResponseEncoder Maven / Gradle / Ivy
/*
* Copyright 2012 The Netty Project
*
* The Netty Project 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:
*
* https://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 io.netty.handler.codec.http;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufUtil;
import static io.netty.handler.codec.http.HttpConstants.*;
/**
* Encodes an {@link HttpResponse} or an {@link HttpContent} into
* a {@link ByteBuf}.
*/
public class HttpResponseEncoder extends HttpObjectEncoder {
@Override
public boolean acceptOutboundMessage(Object msg) throws Exception {
// JDK type checks vs non-implemented interfaces costs O(N), where
// N is the number of interfaces already implemented by the concrete type that's being tested.
// !(msg instanceof HttpRequest) is supposed to always be true (and meaning that msg isn't a HttpRequest),
// but sadly was part of the original behaviour of this method and cannot be removed.
// We place here exact checks vs DefaultHttpResponse and DefaultFullHttpResponse because bad users can
// extends such types and make them to implement HttpRequest (non-sense, but still possible).
final Class msgClass = msg.getClass();
if (msgClass == DefaultFullHttpResponse.class || msgClass == DefaultHttpResponse.class) {
return true;
}
return super.acceptOutboundMessage(msg) && !(msg instanceof HttpRequest);
}
@Override
protected void encodeInitialLine(ByteBuf buf, HttpResponse response) throws Exception {
response.protocolVersion().encode(buf);
buf.writeByte(SP);
response.status().encode(buf);
ByteBufUtil.writeShortBE(buf, CRLF_SHORT);
}
@Override
protected void sanitizeHeadersBeforeEncode(HttpResponse msg, boolean isAlwaysEmpty) {
if (isAlwaysEmpty) {
HttpResponseStatus status = msg.status();
if (status.codeClass() == HttpStatusClass.INFORMATIONAL ||
status.code() == HttpResponseStatus.NO_CONTENT.code()) {
// Stripping Content-Length:
// See https://tools.ietf.org/html/rfc7230#section-3.3.2
msg.headers().remove(HttpHeaderNames.CONTENT_LENGTH);
// Stripping Transfer-Encoding:
// See https://tools.ietf.org/html/rfc7230#section-3.3.1
msg.headers().remove(HttpHeaderNames.TRANSFER_ENCODING);
} else if (status.code() == HttpResponseStatus.RESET_CONTENT.code()) {
// Stripping Transfer-Encoding:
msg.headers().remove(HttpHeaderNames.TRANSFER_ENCODING);
// Set Content-Length: 0
// https://httpstatuses.com/205
msg.headers().setInt(HttpHeaderNames.CONTENT_LENGTH, 0);
}
}
}
@Override
protected boolean isContentAlwaysEmpty(HttpResponse msg) {
// Correctly handle special cases as stated in:
// https://tools.ietf.org/html/rfc7230#section-3.3.3
HttpResponseStatus status = msg.status();
if (status.codeClass() == HttpStatusClass.INFORMATIONAL) {
if (status.code() == HttpResponseStatus.SWITCHING_PROTOCOLS.code()) {
// We need special handling for WebSockets version 00 as it will include an body.
// Fortunally this version should not really be used in the wild very often.
// See https://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-00#section-1.2
return msg.headers().contains(HttpHeaderNames.SEC_WEBSOCKET_VERSION);
}
return true;
}
return status.code() == HttpResponseStatus.NO_CONTENT.code() ||
status.code() == HttpResponseStatus.NOT_MODIFIED.code() ||
status.code() == HttpResponseStatus.RESET_CONTENT.code();
}
}