A combination of HttpRequestEncoder and HttpResponseDecoder which enables easier client side HTTP implementation. HttpClientCodec provides additional state management for HEAD and CONNECT requests, which HttpResponseDecoder lacks. Please refer to HttpResponseDecoder to learn what additional state management needs to be done for HEAD and CONNECT and why HttpResponseDecoder can not handle it by itself.

If the Channel is closed and there are missing responses, a PrematureChannelClosureException is thrown.

Header Validation

It is recommended to always enable header validation.

Without header validation, your system can become vulnerable to CWE-113: Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Response Splitting') .

This recommendation stands even when both peers in the HTTP exchange are trusted, as it helps with defence-in-depth.

Modifier and Type	Class and Description
private class	HttpClientCodec.Decoder
private class	HttpClientCodec.Encoder

Field Summary

Modifier and Type	Field and Description
public static final boolean	DEFAULT_FAIL_ON_MISSING_RESPONSE
public static final boolean	DEFAULT_PARSE_HTTP_AFTER_CONNECT_REQUEST
private boolean	done If true, decoding stops (i.e. pass-through)
private final boolean	failOnMissingResponse
private final boolean	parseHttpAfterConnectRequest
private final Queue<HttpMethod>	queue A queue that is used for correlating a request and a response.
private final AtomicLong	requestResponseCounter

Constructor Summary

Access	Constructor and Description
public	HttpClientCodec() Creates a new instance with the default decoder options (`maxInitialLineLength (4096)`, `maxHeaderSize (8192)`, and `maxChunkSize (8192)`).
public	HttpClientCodec(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize) Creates a new instance with the specified decoder options.
public	HttpClientCodec(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean failOnMissingResponse) Creates a new instance with the specified decoder options.
public	HttpClientCodec(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean failOnMissingResponse, boolean validateHeaders) Deprecated Prefer the `HttpClientCodec(int, int, int, boolean)` constructor, to always enable header validation. Creates a new instance with the specified decoder options.
public	HttpClientCodec(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean failOnMissingResponse, boolean validateHeaders, boolean parseHttpAfterConnectRequest) Deprecated Prefer the `HttpClientCodec(HttpDecoderConfig, boolean, boolean)` constructor, to always enable header validation. Creates a new instance with the specified decoder options.
public	HttpClientCodec(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean failOnMissingResponse, boolean validateHeaders, int initialBufferSize) Deprecated Prefer the `HttpClientCodec(HttpDecoderConfig, boolean, boolean)` constructor, to always enable header validation. Creates a new instance with the specified decoder options.
public	HttpClientCodec(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean failOnMissingResponse, boolean validateHeaders, int initialBufferSize, boolean parseHttpAfterConnectRequest) Deprecated Prefer the `HttpClientCodec(HttpDecoderConfig, boolean, boolean)` constructor, to always enable header validation. Creates a new instance with the specified decoder options.
public	HttpClientCodec(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean failOnMissingResponse, boolean validateHeaders, int initialBufferSize, boolean parseHttpAfterConnectRequest, boolean allowDuplicateContentLengths) Deprecated Prefer the `HttpClientCodec(HttpDecoderConfig, boolean, boolean)` constructor, to always enable header validation. Creates a new instance with the specified decoder options.
public	HttpClientCodec(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean failOnMissingResponse, boolean validateHeaders, int initialBufferSize, boolean parseHttpAfterConnectRequest, boolean allowDuplicateContentLengths, boolean allowPartialChunks) Deprecated Prefer the `HttpClientCodec(HttpDecoderConfig, boolean, boolean)` constructor, to always enable header validation. Creates a new instance with the specified decoder options.
public	HttpClientCodec(HttpDecoderConfig config, boolean parseHttpAfterConnectRequest, boolean failOnMissingResponse) Creates a new instance with the specified decoder options.

Method Summary

Modifier and Type	Method and Description
public boolean	isSingleDecode()
public void	prepareUpgradeFrom(ChannelHandlerContext ctx) Implements io.netty.handler.codec.http.HttpClientUpgradeHandler.SourceCodec.prepareUpgradeFrom. Prepares to upgrade to another protocol from HTTP.
public void	setSingleDecode(boolean singleDecode)
public void	upgradeFrom(ChannelHandlerContext ctx) Implements io.netty.handler.codec.http.HttpClientUpgradeHandler.SourceCodec.upgradeFrom. Upgrades to another protocol from HTTP.

Field Detail

DEFAULT_FAIL_ON_MISSING_RESPONSE	back to summary
public static final boolean DEFAULT_FAIL_ON_MISSING_RESPONSE

DEFAULT_PARSE_HTTP_AFTER_CONNECT_REQUEST	back to summary
public static final boolean DEFAULT_PARSE_HTTP_AFTER_CONNECT_REQUEST

done	back to summary
private boolean done If true, decoding stops (i.e. pass-through)

failOnMissingResponse	back to summary
private final boolean failOnMissingResponse

parseHttpAfterConnectRequest	back to summary
private final boolean parseHttpAfterConnectRequest

queue	back to summary
private final Queue<HttpMethod> queue A queue that is used for correlating a request and a response.

requestResponseCounter	back to summary
private final AtomicLong requestResponseCounter

Constructor Detail

HttpClientCodec	back to summary
public HttpClientCodec() Creates a new instance with the default decoder options (`maxInitialLineLength (4096)`, `maxHeaderSize (8192)`, and `maxChunkSize (8192)`).

HttpClientCodec	back to summary
public HttpClientCodec(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize) Creates a new instance with the specified decoder options.

HttpClientCodec	back to summary
public HttpClientCodec(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean failOnMissingResponse) Creates a new instance with the specified decoder options.

HttpClientCodec back to summary

HttpClientCodec	back to summary
public HttpClientCodec(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean failOnMissingResponse, boolean validateHeaders) Deprecated Prefer the `HttpClientCodec(int, int, int, boolean)` constructor, to always enable header validation. Creates a new instance with the specified decoder options. Annotations @Deprecated

public HttpClientCodec(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean failOnMissingResponse, boolean validateHeaders)

Deprecated

Prefer the HttpClientCodec(int, int, int, boolean) constructor, to always enable header validation.

Creates a new instance with the specified decoder options.

Annotations

@Deprecated

HttpClientCodec back to summary

HttpClientCodec	back to summary
public HttpClientCodec(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean failOnMissingResponse, boolean validateHeaders, boolean parseHttpAfterConnectRequest) Deprecated Prefer the `HttpClientCodec(HttpDecoderConfig, boolean, boolean)` constructor, to always enable header validation. Creates a new instance with the specified decoder options. Annotations @Deprecated

public HttpClientCodec(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean failOnMissingResponse, boolean validateHeaders, boolean parseHttpAfterConnectRequest)

Deprecated

Prefer the HttpClientCodec(HttpDecoderConfig, boolean, boolean) constructor, to always enable header validation.

Creates a new instance with the specified decoder options.

Annotations

@Deprecated

HttpClientCodec back to summary

HttpClientCodec	back to summary
public HttpClientCodec(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean failOnMissingResponse, boolean validateHeaders, int initialBufferSize) Deprecated Prefer the `HttpClientCodec(HttpDecoderConfig, boolean, boolean)` constructor, to always enable header validation. Creates a new instance with the specified decoder options. Annotations @Deprecated

public HttpClientCodec(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean failOnMissingResponse, boolean validateHeaders, int initialBufferSize)

Deprecated

Prefer the HttpClientCodec(HttpDecoderConfig, boolean, boolean) constructor, to always enable header validation.

Creates a new instance with the specified decoder options.

Annotations

@Deprecated

HttpClientCodec back to summary

HttpClientCodec	back to summary
public HttpClientCodec(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean failOnMissingResponse, boolean validateHeaders, int initialBufferSize, boolean parseHttpAfterConnectRequest) Deprecated Prefer the `HttpClientCodec(HttpDecoderConfig, boolean, boolean)` constructor, to always enable header validation. Creates a new instance with the specified decoder options. Annotations @Deprecated

public HttpClientCodec(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean failOnMissingResponse, boolean validateHeaders, int initialBufferSize, boolean parseHttpAfterConnectRequest)

Deprecated

Prefer the HttpClientCodec(HttpDecoderConfig, boolean, boolean) constructor, to always enable header validation.

Creates a new instance with the specified decoder options.

Annotations

@Deprecated

HttpClientCodec back to summary

HttpClientCodec	back to summary
public HttpClientCodec(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean failOnMissingResponse, boolean validateHeaders, int initialBufferSize, boolean parseHttpAfterConnectRequest, boolean allowDuplicateContentLengths) Deprecated Prefer the `HttpClientCodec(HttpDecoderConfig, boolean, boolean)` constructor, to always enable header validation. Creates a new instance with the specified decoder options. Annotations @Deprecated

Deprecated

Prefer the HttpClientCodec(HttpDecoderConfig, boolean, boolean) constructor, to always enable header validation.

Creates a new instance with the specified decoder options.

Annotations

@Deprecated

HttpClientCodec back to summary

HttpClientCodec	back to summary
public HttpClientCodec(int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean failOnMissingResponse, boolean validateHeaders, int initialBufferSize, boolean parseHttpAfterConnectRequest, boolean allowDuplicateContentLengths, boolean allowPartialChunks) Deprecated Prefer the `HttpClientCodec(HttpDecoderConfig, boolean, boolean)` constructor, to always enable header validation. Creates a new instance with the specified decoder options. Annotations @Deprecated

Deprecated

Prefer the HttpClientCodec(HttpDecoderConfig, boolean, boolean) constructor, to always enable header validation.

Creates a new instance with the specified decoder options.

Annotations

@Deprecated

HttpClientCodec	back to summary
public HttpClientCodec(HttpDecoderConfig config, boolean parseHttpAfterConnectRequest, boolean failOnMissingResponse) Creates a new instance with the specified decoder options.

Method Detail

isSingleDecode	back to summary
public boolean isSingleDecode()

prepareUpgradeFrom back to summary

prepareUpgradeFrom	back to summary
public void prepareUpgradeFrom(ChannelHandlerContext ctx) Implements io.netty.handler.codec.http.HttpClientUpgradeHandler.SourceCodec.prepareUpgradeFrom. Prepares to upgrade to another protocol from HTTP. Disables the `Encoder`. Annotations @Override

public void prepareUpgradeFrom(ChannelHandlerContext ctx)

Implements io.netty.handler.codec.http.HttpClientUpgradeHandler.SourceCodec.prepareUpgradeFrom.

Prepares to upgrade to another protocol from HTTP. Disables the Encoder.

Annotations

@Override

setSingleDecode	back to summary
public void setSingleDecode(boolean singleDecode)

upgradeFrom back to summary

upgradeFrom	back to summary
public void upgradeFrom(ChannelHandlerContext ctx) Implements io.netty.handler.codec.http.HttpClientUpgradeHandler.SourceCodec.upgradeFrom. Upgrades to another protocol from HTTP. Removes the `Decoder` and `Encoder` from the pipeline. Annotations @Override

public void upgradeFrom(ChannelHandlerContext ctx)

Implements io.netty.handler.codec.http.HttpClientUpgradeHandler.SourceCodec.upgradeFrom.

Upgrades to another protocol from HTTP. Removes the Decoder and Encoder from the pipeline.

Annotations

@Override

Access	Constructor and Description
pack-priv	Decoder(HttpDecoderConfig config)

Modifier and Type	Method and Description
public void	channelInactive(ChannelHandlerContext ctx) Overrides io.netty.handler.codec.ByteToMessageDecoder.channelInactive. Implements io.netty.channel.ChannelInboundHandler.channelInactive. Calls `ChannelHandlerContext#fireChannelInactive()` to forward to the next `ChannelInboundHandler` in the `ChannelPipeline`.
protected void	decode(ChannelHandlerContext the `ChannelHandlerContext` which this `ByteToMessageDecoder` belongs to ctx, ByteBuf the `ByteBuf` from which to read data buffer, List<Object> the `List` to which decoded messages should be added out) Overrides io.netty.handler.codec.http.HttpObjectDecoder.decode. Decode the from one `ByteBuf` to an other.
private void	decrement(Object msg)
protected boolean	isContentAlwaysEmpty(HttpMessage msg) Overrides io.netty.handler.codec.http.HttpObjectDecoder.isContentAlwaysEmpty.

Decoder	back to summary
pack-priv Decoder(HttpDecoderConfig config)

channelInactive	back to summary
public void channelInactive(ChannelHandlerContext ctx) throws Exception Overrides io.netty.handler.codec.ByteToMessageDecoder.channelInactive. Implements io.netty.channel.ChannelInboundHandler.channelInactive. Doc from io.netty.channel.ChannelInboundHandlerAdapter.channelInactive. Calls `ChannelHandlerContext#fireChannelInactive()` to forward to the next `ChannelInboundHandler` in the `ChannelPipeline`. Sub-classes may override this method to change behavior. Annotations @Override

decode	back to summary
protected void decode(ChannelHandlerContext ctx, ByteBuf buffer, List<Object> out) throws Exception Overrides io.netty.handler.codec.http.HttpObjectDecoder.decode. Doc from io.netty.handler.codec.ByteToMessageDecoder.decode. Decode the from one `ByteBuf` to an other. This method will be called till either the input `ByteBuf` has nothing to read when return from this method or till nothing was read from the input `ByteBuf`. Parameters ctx:ChannelHandlerContext the `ChannelHandlerContext` which this `ByteToMessageDecoder` belongs to buffer:ByteBuf the `ByteBuf` from which to read data out:List<Object> the `List` to which decoded messages should be added Annotations @Override Exceptions Exception: is thrown if an error occurs

decrement	back to summary
private void decrement(Object msg)

isContentAlwaysEmpty	back to summary
protected boolean isContentAlwaysEmpty(HttpMessage msg) Overrides io.netty.handler.codec.http.HttpObjectDecoder.isContentAlwaysEmpty. Annotations @Override

io.netty.handler.codec.http back to summary

private final Class HttpClientCodec.Encoder

Class Inheritance

extends HttpRequestEncoder

java.lang.Object
io.netty.channel.ChannelHandlerAdapter
io.netty.channel.ChannelOutboundHandlerAdapter
io.netty.handler.codec.MessageToMessageEncoder
io.netty.handler.codec.http.HttpObjectEncoder
io.netty.handler.codec.http.HttpRequestEncoder
io.netty.handler.codec.http.HttpClientCodec.Encoder

Field Summary

Modifier and Type	Field and Description
pack-priv boolean	upgraded

Constructor Summary

Access	Constructor and Description
private	Encoder()

Method Summary

Modifier and Type	Method and Description
protected void	encode(ChannelHandlerContext the `ChannelHandlerContext` which this `MessageToMessageEncoder` belongs to ctx, Object the message to encode to an other one msg, List<Object> the `List` into which the encoded msg should be added needs to do some kind of aggregation out) Overrides io.netty.handler.codec.http.HttpObjectEncoder.encode. Encode from one message to an other.

Inherited from io.netty.handler.codec.http.HttpRequestEncoder:: acceptOutboundMessage encodeInitialLine

Field Detail

upgraded	back to summary
pack-priv boolean upgraded

Constructor Detail

Encoder	back to summary
private Encoder()

Method Detail

encode back to summary

encode	back to summary
protected void encode(ChannelHandlerContext ctx, Object msg, List<Object> out) throws Exception Overrides io.netty.handler.codec.http.HttpObjectEncoder.encode. Doc from io.netty.handler.codec.MessageToMessageEncoder.encode. Encode from one message to an other. This method will be called for each written message that can be handled by this encoder. Parameters ctx:ChannelHandlerContext the `ChannelHandlerContext` which this `MessageToMessageEncoder` belongs to msg:Object the message to encode to an other one out:List<Object> the `List` into which the encoded msg should be added needs to do some kind of aggregation Annotations @Override Exceptions Exception: is thrown if an error occurs

protected void encode(ChannelHandlerContext ctx, Object msg, List<Object> out) throws Exception

Overrides io.netty.handler.codec.http.HttpObjectEncoder.encode.

Doc from io.netty.handler.codec.MessageToMessageEncoder.encode.

Encode from one message to an other. This method will be called for each written message that can be handled by this encoder.

Parameters

ctx:ChannelHandlerContext: the ChannelHandlerContext which this MessageToMessageEncoder belongs to
msg:Object: the message to encode to an other one
out:List<Object>: the List into which the encoded msg should be added needs to do some kind of aggregation

Annotations

@Override

Exceptions

Exception:: is thrown if an error occurs

public final Class HttpClientCodec

Header Validation

Nested and Inner Type Summary

Field Summary

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Method Summary

Field Detail

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Method Detail

private final Class HttpClientCodec.Decoder

Constructor Summary

Method Summary

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Method Detail

private final Class HttpClientCodec.Encoder

Field Summary

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Method Detail