Motivation:
Since https://github.com/netty/netty/pull/9865 (Netty 4.1.44) the
default behavior of the HttpObjectDecoder has been to reject any HTTP
message that is found to have multiple Content-Length headers when
decoding. This behavior is well-justified as per the risks outlined in
https://github.com/netty/netty/issues/9861, however, we can see from the
cited RFC section that there are multiple possible options offered for
responding to this scenario:
> If a message is received that has multiple Content-Length header
> fields with field-values consisting of the same decimal value, or a
> single Content-Length header field with a field value containing a
> list of identical decimal values (e.g., "Content-Length: 42, 42"),
> indicating that duplicate Content-Length header fields have been
> generated or combined by an upstream message processor, then the
> recipient MUST either reject the message as invalid or replace the
> duplicated field-values with a single valid Content-Length field
> containing that decimal value prior to determining the message body
> length or forwarding the message.
https://tools.ietf.org/html/rfc7230#section-3.3.2
Netty opted for the first option (rejecting as invalid), which seems
like the safest, but the second option (replacing duplicate values with
a single value) is also valid behavior.
Modifications:
* Introduce "allowDuplicateContentLengths" parameter to
HttpObjectDecoder (defaulting to false).
* When set to true, will allow multiple Content-Length headers only if
they are all the same value. The duplicated field-values will be
replaced with a single valid Content-Length field.
* Add new parameterized test class for testing different variations of
multiple Content-Length headers.
Result:
This is a backwards-compatible change with no functional change to the
existing behavior.
Note that the existing logic would result in NumberFormatExceptions
for header values like "Content-Length: 42, 42". The new logic correctly
reports these as IllegalArgumentException with the proper error message.
Additionally note that this behavior is only applied to HTTP/1.1, but I
suspect that we may want to expand that to include HTTP/1.0 as well...
That behavior is not modified here to minimize the scope of this change.
Motivation:
AbstractDiskHttpData may cause a memory leak when a CompositeByteBuf is used. This happened because we may call copy() but actually never release the newly created ByteBuf.
Modifications:
- Remove copy() call and just use ByteBuf.getBytes(...) which will internally handle the writing to the FileChannel without any extra copies that need to be released later on.
- Add unit test
Result:
Fixes https://github.com/netty/netty/issues/10354
Motivation
HttpObjectDecoder and its associated classes make frequent use of
default values for maxInitialLineLength, maxHeaderSize, maxChunkSize,
etc. Today, these defaults are defined in-line in constructors and
duplicated across many classes. This repetition is more prone to error
and inconsistencies.
Furthermore, due to the current lack of builder support, if a user wants
to change just one of these values (e.g., maxHeaderSize), they are also
required to know and repeat the other default values (e.g.,
maxInitialLineLength and maxChunkSize).
The primary motivation for this change is as we are considering adding
another constructor parameter (for multiple content length behavior),
appending this parameter may require some users to have prior knowledge
of the default initialBufferSize, and it would be cleaner to allow them
to reference the default constant.
Modifications
* Consolidate the HttpObjectDecoder default values into public constants
* Reference these constants where possible
Result
No functional change. Additional telescoping constructors will be easier
and safer to write. Users may have an easier experience changing single
parameters.
Motivation:
`containsValue()` will check if there are multiple values defined in the specific header name, we need to use this method instead of `contains()` for the `Transfer-Encoding` header to cover the case that multiple values defined, like: `Transfer-Encoding: gzip, chunked`
Modification:
Change from `contains()` to `containsValue()` in `HttpUtil.isTransferEncodingChunked()` method.
Result:
Fixes#10320
Motivation:
Currently we passing custom websocket handshaker response headers to a `WebSocketServerHandshaker` but they can contain a reserved headers (e.g. Connection, Upgrade, Sec-Websocket-Accept) what lead to duplication because we use response.headers().add(..) instead of response.headers().set(..).
Modification:
In each `WebSocketServerHandshaker00`, ... `WebSocketServerHandshaker13` implementation replace the method add(..) to set(..) for reserved response headers.
Result:
Less error-prone
Motivation:
`FileChannel.read()` may throw an IOException. We must deal with this in case of the occurrence of `I/O` error.
Modification:
Place the `FileChannel.read()` method call in the `try-finally` block.
Result:
Advoid fd leak.
Co-authored-by: Norman Maurer <norman_maurer@apple.com>
Motivations
-----------
HttpPostStandardRequestDecoder was changed in 4.1.50 to provide its own
ByteBuf UrlDecoder. Prior to this change, it was using the decodeComponent
method from QueryStringDecoder which decoded + characters to
whitespaces. This behavior needs to be preserved to maintain backward
compatibility.
Modifications
-------------
Changed HttpPostStandardRequestDecoder to detect + bytes and decode them
toe whitespaces. Added a test.
Results
-------
Addresses issues#10284
Motivation:
We cant reuse the ChannelPromise as it will cause an error when trying to ful-fill it multiple times.
Modifications:
- Use a new promise and chain it with the old one
- Add unit test
Result:
Fixes https://github.com/netty/netty/issues/10240
Motivation:
Handling of `WebSocketCloseFrame` is part of websocket protocol, so it's logical to put it within the `WebSocketProtocolHandler`. Also, removal of `WebSocketCloseFrameHandler` will decrease the channel pipeline.
Modification:
- `WebSocketCloseFrameHandler` code merged into `WebSocketProtocolHandler`. `WebSocketCloseFrameHandler` not added to the pipeline anymore
- Added additional constructor to `WebSocketProtocolHandler`
- `WebSocketProtocolHandler` now implements `ChannelOutboundHandler` and implements basic methods from it
Result:
`WebSocketCloseFrameHandler` is no longer used.
Fixes https://github.com/netty/netty/issues/9944
Motivation:
We should not use Unpooled to allocate buffers if possible to ensure we can make use of pooling etc.
Modifications:
- Only allocate a buffer if really needed
- Use the ByteBufAllocator of the offered ByteBuf
- Ensure we not use buffer.copy() but explicitly allocate a buffer and then copy into it to not hit the limit of maxCapacity()
Result:
Improve allocations
Motivation:
We need to release all ByteBufs that we allocate to prevent leaks. We missed to release the ByteBufs that are used to aggregate in two cases
Modifications:
Add release() calls
Result:
No more memory leak in HttpPostMultipartRequestDecoder
Motivations
-----------
There is no need to copy the "offered" ByteBuf in HttpPostRequestDecoder
when the first HttpContent ByteBuf is also the last (LastHttpContent) as
the full content can immediately be decoded. No extra bookeeping needed.
Modifications
-------------
HttpPostMultipartRequestDecoder
- Retain the first ByteBuf when it is both the first HttpContent offered
to the decoder and is also LastHttpContent.
- Retain slices of the final buffers values
Results
-------
ByteBufs of FullHttpMessage decoded by HttpPostRequestDecoder are no longer
unnecessarily copied. Attributes are extracted as retained slices when
the content is multi-part. Non-multi-part content continues to return
Unpooled buffers.
Partially addresses issue #10200
Motivation:
`AbstractHttpData.checkSize` may throw an IOException if we set the max size limit via `AbstractHttpData.setMaxSize`. However, if this exception happens, the `AbstractDiskHttpData.file` and the `AbstractHttpData.size` are still be modified. In other words, it may break the failure atomicity here.
Modification:
Just move up the size check.
Result:
Keep the failure atomicity even if `AbstractHttpData.checkSize` fails.
Motivation:
An unexpected IOException may be thrown from `FileChannel.force`. If it happens, the `FileChannel.close` may not be invoked.
Modification:
Place the `FileChannel.close` in a finally block.
Result:
Avoid fd leak.
Motivation:
`RandomAccessFile.setLength` may throw an IOException. We must deal with this in case of the occurrence of `I/O` error.
Modification:
Place the `RandomAccessFile.setLength` method call in the `try-finally` block.
Result:
Avoid fd leak.
Motivation:
`FileChannel.force` may throw an IOException. A fd leak may happen here.
Modification:
Close the fileChannel in a finally block.
Result:
Avoid fd leak.
Motivation:
An `IOException` may be thrown from `FileChannel.write` or `FileChannel.force`, and cause the fd leak.
Modification:
Close the file in a finally block.
Result:
Avoid fd leak.
Motivation:
An IOException may be thrown from FileChannel.read, and cause the fd leak.
Modification:
Close the file when IOException occurs.
Result:
Avoid fd leak.
Motivation:
currently (http) disk based attributes or uploads are globally configured in a single directory and can also only globally be deleted on exit or not. it does not fit well multiple cases, in particular the case you have multiple servers in the same JVM.
Modification:
make it configurable per attribute/fileupload.
Result:
This PR duplicates Disk* constructor to add basedir and deleteonexit parameters and wires it in default http daa factory.
Motivation:
An IOException may be thrown from InputStream.read or checkSize method, and cause the ByteBuf leak.
Modification:
Release the ByteBuf when IOException occurs.
Result:
Avoid ByteBuf leak.
Motivation:
At the moment HttpObjectDecoder does not limit the number of controls chars. These should be counted with the initial line and so a limit should be exposed
Modifications:
- Change LineParser to also be used when skipping control chars and so enforce a limit
- Add various tests to ensure that limit is enforced
Result:
Fixes https://github.com/netty/netty/issues/10111
Motivation:
In our WebSocketClientHandshaker* implementations we "hardcode" the version number to use. This is error-prone, we should better use the WebSocketVersion so we dont need to maintain the value multiple times. Beside this we can also use an AsciiString to improve performance
Modifications:
- Use WebSocketVersion.toAsciiString
Result:
Less stuff to maintain and small performance win
Motivation:
The user may need to provide a specific HOST header. We should not override it when specified during handshake.
Modifications:
Check if a custom HOST header is already provided by the user and if so dont override it
Result:
Fixes https://github.com/netty/netty/issues/10101
Motivation:
Netty currently does not support the SameSite attribute for response cookies (see issue #8161 for discussion).
Modifications:
The attribute has been added to the DefaultCookie class as a quick fix since adding new methods to the Cookie interface would be backwards-incompatible.
ServerCookieEncoder and ClientCookieDecoder have been updated accordingly to process this value. No validation for allowed values (Lax, None, Strict) has been implemented.
Result:
Response cookies with the SameSite attribute set can be read or written by Netty.
Co-authored-by: David Latorre <a-dlatorre@hotels.com>
Motivation:
WebSocketClientHandshaker#upgradeUrl doesn't comperly compute relative url when path is empty and produces url such as `?access_token=foo` instead of `/?access_token=foo`.
Modifications:
* fix WebSocketClientHandshaker#upgradeUrl
* add tests for urls without path, with and without query
Result:
WebSocketClientHandshaker properly connects to url without path.
Motivation:
I am receiving a mutlipart/form_data upload from postman. The filename contains Chinese, and so some invalid chars. We should ensure all of these are removed before trying to decode.
Modification:
Ensure all invalid characters are removed
Result:
Fixes#10087
Co-authored-by: liming.zhang <liming.zhang@luckincoffee.com>
Motivation:
At the moment the next / prev references are not set to "null" in the DefaultChannelHandlerContext once the ChannelHandler is removed. This is bad as it basically let users still use the ChannelHandlerContext of a ChannelHandler after it is removed and may produce very suprising behaviour.
Modifications:
- Fail if someone tries to use the ChannelHandlerContext once the ChannelHandler was removed (for outbound operations fail the promise, for inbound fire the error through the ChannelPipeline)
- Fix some handlers to ensure we not use the ChannelHandlerContext after the handler was removed
- Adjust DefaultChannelPipeline / DefaultChannelHandlerContext to fixes races with removal / replacement of handlers
Result:
Cleanup behaviour and make it more predictable for pipeline modifications
Motivation:
Our parsing of the initial line / http headers did treat some characters as separators which should better trigger an exception during parsing.
Modifications:
- Tighten up parsing of the inital line by follow recommentation of RFC7230
- Restrict separators to OWS for http headers
- Add unit test
Result:
Stricter parsing of HTTP1
Motivation:
We did had some System.out.println(...) call in a test which seems to be some left-over from debugging.
Modifications:
Remove System.out.println(...)
Result:
Code cleanup
Motivation
As part of a recent commit for issue
https://github.com/netty/netty/issues/9861 the HttpObjectDecoder was
changed to throw an IllegalArgumentException (and produce a failed
decoder result) when decoding a message with both "Transfer-Encoding:
chunked" and "Content-Length".
While it seems correct for Netty to try to sanitize these types of
messages, the spec explicitly mentions that the Content-Length header
should be *removed* in this scenario.
Both Nginx 1.15.9 and Tomcat 9.0.31 also opt to remove the header:
b693d7c198/java/org/apache/coyote/http11/Http11Processor.java (L747-L755)0ad4393e30/src/http/ngx_http_request.c (L1946-L1953)
Modifications
* Change the default behavior from throwing an IllegalArgumentException
to removing the "Content-Length" header
* Extract the behavior to a new protected method,
handleChunkedEncodingWithContentLength(), that can be overridden to
change this behavior (or capture metrics)
Result
Messages of this nature will now be successfully decoded and have their
"Content-Length" header removed, rather than creating invalid messages
(decoder result failures). Users will be allowed to override and
configure this behavior.
Motivation:
Need tests to ensure that CVE-2020-7238 is fixed.
Modifications:
Added two test cases into HttpRequestDecoderTest which check that
no whitespace is allowed before the Transfer-Encoding header.
Result:
Improved test coverage for #9861
Motivation:
Avoid allocation of default static `WebSocketServerProtocolConfig` and `WebSocketClientProtocolConfig` configs. Prefer compile time constants instead.
Modification:
Static field with config object replaced with constructor with default fields.
Result:
No more default config allocation and static field for it. Compile time variables used instead.
Motivation:
At the moment we add a handler which will respond with 403 forbidden if a websocket handshake is in progress (and after). This makes not much sense as it is unexpected to have a remote peer to send another http request when the handshake was started. In this case it is much better to let the websocket decoder bail out.
Modifications:
Remove usage of forbiddenHttpRequestResponder
Result:
Fixes https://github.com/netty/netty/issues/9913
Motivation:
In next major version of netty users should use ChannelHandler everywhere. We should ensure we do the same
Modifications:
Replace usage of deprecated classes / interfaces with ChannelHandler
Result:
Use non-deprecated code
Motivation:
We should remove WebSocketServerExtensionHandler from pipeline after successful WebSocket upgrade even if the client has not selected any extensions.
Modification:
Remove handler once upgrade is complete and no extensions are used.
Result:
Fixes#9939.
Motivation:
Utf8FrameValidator must release the input buffer if the validation fails to ensure no memory leak happens
Modifications:
- Catch exception, release frame and rethrow
- Adjust unit test
Result:
Fixes https://github.com/netty/netty/issues/9906
Motivation:
Currently, characters are appended to the encoded string char-by-char even when no encoding is needed. We can instead separate out codepath that appends the entire string in one go for better `StringBuilder` allocation performance.
Modification:
Only go into char-by-char loop when finding a character that requires encoding.
Result:
The results aren't so clear with noise on my hot laptop - the biggest impact is on long strings, both to reduce resizes of the buffer and also to reduce complexity of the loop. I don't think there's a significant downside though for the cases that hit the slow path.
After
```
Benchmark Mode Cnt Score Error Units
QueryStringEncoderBenchmark.longAscii thrpt 6 1.406 ± 0.069 ops/us
QueryStringEncoderBenchmark.longAsciiFirst thrpt 6 0.046 ± 0.001 ops/us
QueryStringEncoderBenchmark.longUtf8 thrpt 6 0.046 ± 0.001 ops/us
QueryStringEncoderBenchmark.shortAscii thrpt 6 15.781 ± 0.949 ops/us
QueryStringEncoderBenchmark.shortAsciiFirst thrpt 6 3.171 ± 0.232 ops/us
QueryStringEncoderBenchmark.shortUtf8 thrpt 6 3.900 ± 0.667 ops/us
```
Before
```
Benchmark Mode Cnt Score Error Units
QueryStringEncoderBenchmark.longAscii thrpt 6 0.444 ± 0.072 ops/us
QueryStringEncoderBenchmark.longAsciiFirst thrpt 6 0.043 ± 0.002 ops/us
QueryStringEncoderBenchmark.longUtf8 thrpt 6 0.047 ± 0.001 ops/us
QueryStringEncoderBenchmark.shortAscii thrpt 6 16.503 ± 1.015 ops/us
QueryStringEncoderBenchmark.shortAsciiFirst thrpt 6 3.316 ± 0.154 ops/us
QueryStringEncoderBenchmark.shortUtf8 thrpt 6 3.776 ± 0.956 ops/us
```
Motivation:
https://github.com/netty/netty/pull/9883 added a bug-fix for the Comparator in ClientCookieEncoder but did not add a testcase.
Modifications:
- Add testcase
- Simplify code
Result:
Include a test to ensure we not regress.
Motivation:
The current implementation causes IllegalArgumetExceptions to be thrown on Java 11.
The current implementation would violate comparison contract for two cookies C1 and C2 with same path length, since C1 < C2 and C2 < C1. Returning 0 (equality) does not since C1 == C2 and C2 == C1. See #9881
Modification:
Return equality instead of less than on same path length.
Result:
Fixes#9881.
Motivation:
In Java, it is almost always at least slower to use `ByteBuffer` than `byte[]` without pooling or I/O. `QueryStringDecoder` can use `byte[]` with arguably simpler code.
Modification:
Replace `ByteBuffer` / `CharsetDecoder` with `byte[]` and `new String`
Result:
After
```
Benchmark Mode Cnt Score Error Units
QueryStringDecoderBenchmark.noDecoding thrpt 6 5.612 ± 2.639 ops/us
QueryStringDecoderBenchmark.onlyDecoding thrpt 6 1.393 ± 0.067 ops/us
QueryStringDecoderBenchmark.mixedDecoding thrpt 6 1.223 ± 0.048 ops/us
```
Before
```
Benchmark Mode Cnt Score Error Units
QueryStringDecoderBenchmark.noDecoding thrpt 6 6.123 ± 0.250 ops/us
QueryStringDecoderBenchmark.onlyDecoding thrpt 6 0.922 ± 0.159 ops/us
QueryStringDecoderBenchmark.mixedDecoding thrpt 6 1.032 ± 0.178 ops/us
```
I notice #6781 switched from an array to `ByteBuffer` but I can't find any motivation for that in the PR. Unit tests pass fine with an array and we get a reasonable speed bump.
Motivation:
ByteToMessageDecoder requires using an intermediate List to put results into. This intermediate list adds overhead (memory/CPU) which grows as the number of objects increases. This overhead can be avoided by directly propagating events through the ChannelPipeline via ctx.fireChannelRead(...). This also makes the semantics more clear and allows us to keep track if we need to call ctx.read() in all cases.
Modifications:
- Remove List from the method signature of ByteToMessageDecoder.decode(...) and decodeLast(...)
- Adjust all sub-classes
- Adjust unit tests
- Fix javadocs.
Result:
Adjust ByteToMessageDecoder as noted in https://github.com/netty/netty/issues/8525.
Motivation:
RFC7230 states that we should not accept multiple content-length headers and also should not accept a content-length header in combination with transfer-encoding: chunked
Modifications:
- Check for multiple content-length headers and if found mark message as invalid
- Check if we found a content-length header and also a transfer-encoding: chunked and if so mark the message as invalid
- Add unit test
Result:
Fixes https://github.com/netty/netty/issues/9861
Motivation:
Technical speaking its valid to have http headers with no values so we should support it. That said we need to detect if these are "generated" because of an "invalid" fold.
Modifications:
- Detect if a colon is missing when parsing headers.
- Add unit test
Result:
Fixes https://github.com/netty/netty/issues/9866
Motivation:
Client can split data into different numbers of fragments and sometimes the last frame may contain trash data that doesn't affect decompression process.
Modification:
Added check if last frame is `ContinuationWebSocketFrame` and decompression data is empty
then don't throw an exception.
Result:
Fixes#9770
Motivation:
Multiple cookie values can be present in a single header.
Modification:
Add `decodeAll` overload which returns all cookies
Result:
Fixes#7210
Note:
This change is not as perscriptive as the ideas brought up in the linked issue. Changing the Set implementation or the equals/compareTo definition is likely a breaking change, so they are practical.
Motivation:
We should use Objects.requireNonNull(...) as we require java8
Modifications:
Replace ObjectUtil.checkNonNull(...) with Objects.requireNonNull(...)
Result:
Code cleanup
Motivation:
HttpPostStandardRequestDecoder may throw multiple different exceptions in the constructor which could lead to memory leaks. We need to guard against this by explicit catch all of them and rethrow after we released any allocated memory.
Modifications:
- Catch, destroy and rethrow in any case
- Ensure we correctly wrap IllegalArgumentExceptions
- Add unit tests
Result:
Fixes https://github.com/netty/netty/issues/9829
Those who need 'Origin' or 'Sec-WebSocket-Origin' headers should provide them explicitly, like it is stated in WebSocket specs.
E.g. through custom headers:
HttpHeaders customHeaders = new DefaultHttpHeaders()
.add(HttpHeaderNames.ORIGIN, "http://localhost:8080");
new WebSocketClientProtocolHandler(
new URI("ws://localhost:1234/test"), WebSocketVersion.V13, subprotocol,
allowExtensions, customHeaders, maxFramePayloadLength, handshakeTimeoutMillis)
* Remove enforced origin headers.
* Update tests
Fixes#9673: Origin header is always sent from WebSocket client
Motivation:
7ff8cde66f introduced some tests which needs some small adjustments for master.
Modifications:
Add explicit casts
Result:
master builds again without test failures
Motivation:
By default CloseWebSocketFrames are handled automatically.
However I need manually manage their sending both on client- and on server-sides.
Modification:
Send close frame on channel close automatically, when it was not send before explicitly.
Result:
No more messages like "Connection closed by remote peer" for normal close flows.
Motivation
Per javadoc in 4.1.x SimpleChannelInboundHandler:
"Please keep in mind that channelRead0(ChannelHandlerContext, I) will be
renamed to messageReceived(ChannelHandlerContext, I) in 5.0."
Modifications
Rename aforementioned method and all references/overrides.
Result
Method is renamed.
### Motivation:
Introduction of `WebSocketDecoderConfig` made our server-side code more elegant and simpler for support.
However there is still some problem with maintenance and new features development for WebSocket codecs (`WebSocketServerProtocolHandler`, `WebSocketServerProtocolHandler`).
Particularly, it makes me ~~crying with blood~~ extremely sad to add new parameter and yet another one constructor into these handlers, when I want to contribute new feature.
### Modification:
I've extracted all parameters for client and server WebSocket handlers into config/builder structures, like it was made for decoders in PR #9116.
### Result:
* Fixes#9698: Simplify WebSocket handlers constructor arguments hell
* Unblock further development in this module (configurable close frame handling on server-side; automatic close-frame sending, when missed; memory leaks on protocol violations; etc...)
Bonuses:
* All defaults are gathered in one place and could be easily found/reused.
* New API greatly simplifies usage, but does NOT allow inheritance or modification.
* New API would simplify long-term maintenance of WebSockets module.
### Example
WebSocketClientProtocolConfig config = WebSocketClientProtocolConfig.newBuilder()
.webSocketUri("wss://localhost:8443/fx-spot")
.subprotocol("trading")
.handshakeTimeoutMillis(15000L)
.build();
ctx.pipeline().addLast(new WebSocketClientProtocolHandler(config));
Motivation:
At the moment we miss to poll the method queue when we see an Informational response code. This can lead to out-of-sync of request / response pairs when later try to compare these.
Modifications:
Always poll the queue correctly
Result:
Always compare the correct request / response pairs
Motivation:
HTTP 102 (WebDAV) is not correctly treated as an informational response
Modification:
Delegate all `1XX` status codes to superclass, not just `100` and `101`.
Result:
Supports WebDAV response.
Removes a huge maintenance [headache](https://github.com/line/armeria/pull/2210) in Armeria which has forked the class for these features
Motivation:
HttpPostRequestDecoder.splitHeaderContentType() throws a StringIndexOutOfBoundsException when it parses a Content-Type header that starts with a semicolon ;. We should skip the execution for incorrect multipart form data.
Modification:
Avoid invocation of HttpPostRequestDecoder#splitHeaderContentType(...) for incorrect multipart form data content-type.
Result:
Fixes#8554
### Motivation:
I've now found two libraries that use Netty to be vulnerable to [CWE-113: Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Response Splitting')](https://cwe.mitre.org/data/definitions/113.html) due to using `new DefaultHttpHeaders(false)`.
Some part of me hopes that this warning will help dissuade library authors from disabling this important security check.
### Modification:
Add documentation to `DefaultHttpHeaders(boolean)` to warn about the implications of `false`.
### Result:
This improves the documentation on `DefaultHttpHeaders`.
Motivation:
Optimize the QueryStringEncoder for lower memory overhead and higher encode speed.
Modification:
Encode the space to + directly, and reuse the uriStringBuilder rather then create a new one.
Result:
Improved performance
Motivation:
When parsing HTTP headers special care needs to be taken when a whitespace is detected in the header name.
Modifications:
- Ignore whitespace when decoding response (just like before)
- Throw exception when whitespace is detected during parsing
- Add unit tests
Result:
Fixes https://github.com/netty/netty/issues/9571
Motivation:
At the current moment HttpContentEncoder handle only first value of multiple accept-encoding headers.
Modification:
Join multiple accept-encoding headers to one separated by comma.
Result:
Fixes#9553
Motivation:
At the moment it is quite easy to hit reentrance issues when you have multiple handlers in the pipeline and each of the handlers does not correctly protect against these. To make it easier for the user we should try to protect from these. The issue is usually if and inbound event will trigger and outbound event and this outbound event then against triggeres an inbound event. This may result in having methods in a ChannelHandler re-enter some method and so state can be corrupted or messages be re-ordered.
Modifications:
- Keep track of inbound / outbound operations in DefaultChannelHandlerContext and if reentrancy is detected break it by scheduling the action on the EventLoop. This will then be picked up once the method returns and so the reentrancy is broken up.
- Adjust tests which made strange assumptions about execution order
Result:
No more reentrancy of handlers possible.
Motivation:
Currently when HttpPostStandardRequestDecoder throws a ErrorDataDecoderException during construction we leak memory. We need to ensure all is released correctly.
Modifications:
- Call destroy() if parseBody() throws and rethrow the ErrorDataDecoderException
- Add unit test
Result:
Fixes https://github.com/netty/netty/issues/9513.
Motivation:
We did not correctly pass all supplied parameters to the called constructor and so did not apply the timeout.
Modification:
Correctly pass on the parameters.
Result:
Use timeout
Motivation:
Some of the links in javadoc point to the obsolete drafts of HTTP/2
specifications. We should point them to the latest RFC 7540 or 7541.
Modifications:
Update links from `draft-ietf-httpbis-*` to the `rfc7540` and `rfc7541`.
Result:
Correct links in javadoc.
Motivation:
`HttpObjectDecoder` pre-checks that it doesn't request characters
outside of the `AppendableCharSequence`'s length. `0` is always allowed
because the minimal length of `AppendableCharSequence` is `1`. We can
legally skip index check by using
`AppendableCharSequence.charAtUnsafe(int)` in all existing cases in
`HttpObjectDecoder`.
Modifications:
- Use `AppendableCharSequence.charAtUnsafe(int)` instead of
`AppendableCharSequence.charAt(int)` in `HttpObjectDecoder`.
Result:
No unnecessary index checks in `HttpObjectDecoder`.
Motivation:
Http post request may be encoded as 'multipart/form-data' without any files and consist mixed attributes only.
Modifications:
- Do not double release attributes
- Add unit test
Result:
Code does not throw an IllegalReferenceCountException.
Motivation:
We need to ensure we replace WebSocketServerProtocolHandshakeHandler before doing the actual handshake as the handshake itself may complete directly and so forward pending bytes through the pipeline.
Modifications:
Replace the handler before doing the actual handshake.
Result:
Fixes https://github.com/netty/netty/issues/9471.
Motivation:
If all we need is the FileChannel we should better use RandomAccessFile as FileInputStream and FileOutputStream use a finalizer.
Modifications:
Replace FileInputStream and FileOutputStream with RandomAccessFile when possible.
Result:
Fixes https://github.com/netty/netty/issues/8078.
Motivation:
It was possible to produce a NPE when we for examples received more responses as requests as we did not check if the queue did not contain a method before trying to compare method names.
Modifications:
- Add extra null check
- Add unit tet
Result:
Fixes https://github.com/netty/netty/issues/9459
Motivation:
We did not correctly pass the mask parameters in all cases.
Modifications:
Correctly pass on parameters
Result:
Fixes https://github.com/netty/netty/issues/9463.
Motivation:
Allow to set the ORIGIN header value from custom headers in WebSocketClientHandshaker
Modification:
Only override header if not present already
Result:
More flexible handshaker usage
Motivation:
If the HttpUtil.getCharset method is called with an illegal charset like
"charset=!illegal!" it throws an IllegalCharsetNameException. But the javadoc
states, that defaultCharset is returned if incorrect header value. Since the
client sending the request sets the header value this should not crash.
Modification:
HttpUtil.getCharset catches the IllegalCharsetNameException and returns the
defualt value.
Result:
HttpUtil.getCharset does not throw IllegalCharsetNameException any more.
…ryWebSocketFrames
Motivation:
`Utf8FrameValidator` is always created and added to the pipeline in `WebSocketServerProtocolHandler.handlerAdded` method. However, for websocket connection with only `BinaryWebSocketFrame`'s UTF8 validator is unnecessary overhead. Adding of `Utf8FrameValidator` could be easily avoided by extending of `WebSocketDecoderConfig` with additional property.
Specification requires UTF-8 validation only for `TextWebSocketFrame`.
Modification:
Added `boolean WebSocketDecoderConfig.withUTF8Validator` that allows to avoid adding of `Utf8FrameValidator` during pipeline initialization.
Result:
Less overhead when using only `BinaryWebSocketFrame`within web socket.
Motivation:
Our QA servers are spammed with this messages:
13:57:51.560 DEBUG- Decoding WebSocket Frame opCode=1
13:57:51.560 DEBUG- Decoding WebSocket Frame length=4
I think this is too much info for debug level. It is better to move it to trace level.
Modification:
logger.debug changed to logger.trace for WebSocketFrameEncoder/Decoder
Result:
Less messages in Debug mode.
Motivation:
In many places Netty uses Unpooled.buffer(0) while should use EMPTY_BUFFER. We can't change this due to back compatibility in the constructors but can use Unpooled.EMPTY_BUFFER in some cases to ensure we not allocate at all. In others we can directly use the allocator either from the Channel / ChannelHandlerContext or the request / response.
Modification:
- Use Unpooled.EMPTY_BUFFER where possible
- Use allocator where possible
Result:
Fixes#9345 for websockets and http package
Motivation:
We need to ensure we place the encoder before the decoder when doing the websockets upgrade as the decoder may produce a close frame when protocol violations are detected.
Modifications:
- Correctly place encoder before decoder
- Add unit test
Result:
Fixes https://github.com/netty/netty/issues/9300
Motivation:
If the encoded value of a form element happens to exactly hit
the chunk limit (8096 bytes), the post request encoder will
throw a NullPointerException.
Modifications:
Catch the null case and return.
Result:
No NPE.
Motivation:
While fixing #9359 found few places that could be patched / improved separately.
Modification:
On handshake response generation - throw exception before allocating response objects if request is invalid.
Result:
No more leaks when exception is thrown.
Motivation:
Based on https://tools.ietf.org/html/rfc6455#section-1.3 - for non-browser
clients, Origin header field may be sent if it makes sense in the context of those clients.
Modification:
Replace Sec-WebSocket-Origin to Origin
Result:
Fixes#9134 .
Motivation:
Netty homepage(netty.io) serves both "http" and "https".
It's recommended to use https than http.
Modification:
I changed from "http://netty.io" to "https://netty.io"
Result:
No effects.
Motivation:
There are is some unnecessary code (like toString() calls) which can be cleaned up.
Modifications:
- Remove not needed toString() calls
- Simplify subString(...) calls
- Remove some explicit casts when not needed.
Result:
Cleaner code
Motivation:
asList should only be used if there are multiple elements.
Modification:
Call to asList with only one argument could be replaced with singletonList
Result:
Cleaner code and a bit of memory savings
Motivation:
The HttpPostRequestEncoder overwrites the original filename of file uploads sharing the same name encoded in mixed mode when it rewrites the multipart body header of the previous file. The original filename should be preserved instead.
Modifications:
Change the HttpPostRequestEncoder to reuse the correct filename when the encoder switches to mixed mode. The original test is incorrect and has been modified too, in addition it tests with an extra file upload since the current test was not testing the continuation of a mixed mode.
Result:
The HttpPostRequestEncoder will preserve the original filename of the first fileupload when switching to mixed mode
Motivation:
I need to control WebSockets inbound flow manually, when autoRead=false
Modification:
Add missed ctx.read() call into WebSocketProtocolHandler, where read request has been swallowed.
Result:
Fixes#9257
Motivation:
Incorrect WebSockets closure affects our production system.
Enforced 'close socket on any protocol violation' prevents our custom termination sequence from execution.
Huge number of parameters is a nightmare both in usage and in support (decoders configuration).
Modification:
- Fix violations handling - send proper response codes.
- Fix for messages leak.
- Introduce decoder's option to disable default behavior (send close frame) on protocol violations.
- Encapsulate WebSocket response codes - WebSocketCloseStatus.
- Encapsulate decoder's configuration into a separate class - WebSocketDecoderConfig.
Result:
Fixes#8295.
Motivation:
When connecting through an HTTP proxy over clear HTTP, user agents must send requests with an absolute url. This hold true for WebSocket Upgrade request.
WebSocketClientHandshaker and subclasses currently always send requests with a relative url, which causes proxies to crash as request is malformed.
Modification:
Introduce a new parameter `absoluteUpgradeUrl` and expose it in constructors and WebSocketClientHandshakerFactory.
Result:
It's now possible to configure WebSocketClientHandshaker so it works properly with HTTP proxies over clear HTTP.
delete Other "Content-" MIME Header Fields exception
Motivation:
RFC7578 4.8. Other "Content-" Header Fields
The multipart/form-data media type does not support any MIME header
fields in parts other than Content-Type, Content-Disposition, and (in
limited circumstances) Content-Transfer-Encoding. Other header
fields MUST NOT be included and MUST be ignored.
Modification:
Ignore other Content types.
Result:
Other "Content-" Header Fields should be ignored no exception
Motivation:
f17bfd0f64 removed the usage of static exception instances to reduce the risk of OOME due addSupressed calls. We should do the same for exceptions used to signal handshake timeouts.
Modifications:
Do not use static instances
Result:
No risk of OOME due addSuppressed calls
Motivation:
The first final version of GraalVM was released which deprecated some flags. We should use the new ones.
Modifications:
Removes the use of deprecated GraalVM native-image flags
Adds a flag to initialize netty at build time.
Result:
Do not use deprecated flags
Motivation:
Support handshake timeout option in websocket handlers. It makes sense to limit the time we need to move from `HANDSHAKE_ISSUED` to `HANDSHAKE_COMPLETE` states when upgrading to WebSockets
Modification:
- Add `handshakeTimeoutMillis` option in `WebSocketClientProtocolHandshakeHandler` and `WebSocketServerProtocolHandshakeHandler`.
- Schedule a timeout task, the task will trigger user event `HANDSHAKE_TIMEOUT` if the handshake timed out.
Result:
Fixes issue https://github.com/netty/netty/issues/8841
Motivation
Pipeline handlers are free to "take control" of input buffers if they have singular refcount - in particular to mutate their raw data if non-readonly via discarding of read bytes, etc.
However there are various places (primarily unit tests) where a wrapped byte-array buffer is passed in and the wrapped array is assumed not to change (used after the wrapped buffer is passed to EmbeddedChannel.writeInbound()). This invalid assumption could result in unexpected errors, such as those exposed by #8931.
Modifications
Anywhere that the data passed to writeInbound() might be used again, ensure that either:
- A copy is used rather than wrapping a shared byte array, or
- The buffer is otherwise protected from modification by making it read-only
For the tests, copying is preferred since it still allows the "mutating" optimizations to be exercised.
Results
Avoid possible errors when pipeline assumes it has full control of input buffer.
Motivation:
OOME is occurred by increasing suppressedExceptions because other libraries call Throwable#addSuppressed. As we have no control over what other libraries do we need to ensure this can not lead to OOME.
Modifications:
Only use static instances of the Exceptions if we can either dissable addSuppressed or we run on java6.
Result:
Not possible to OOME because of addSuppressed. Fixes https://github.com/netty/netty/issues/9151.
Motivation:
GraalVM native images are a new way to deliver java applications. Netty is one of the most popular libraries however there are a few limitations that make it impossible to use with native images out of the box. Adding a few metadata (in specific modules will allow the compilation to success and produce working binaries)
Modification:
Added properties files in `META-INF` and substitutions classes (under `internal.svm`) will solve the compilation issues. The substitutions classes are not visible and do not have a public constructor so they are not visible to end users.
Result:
Fixes#8959
This fix is very conservative as it applies the minimum config required to build:
* pure netty servers
* vert.x applications
* grpc applications
The build is having trouble due to checkstyle which does not seem to be able to find the copyright notice on property files.
Motivation:
RFC 6455 defines that, generally, a WebSocket client should not close a TCP
connection as far as a server is the one who's responsible for doing that.
In practice tho', it's not always possible to control the server. Server's
misbehavior may lead to connections being leaked (if the server does not
comply with the RFC).
RFC 6455 #7.1.1 says
> In abnormal cases (such as not having received a TCP Close from the server
after a reasonable amount of time) a client MAY initiate the TCP Close.
Modifications:
* WebSocket client handshaker additional param `forceCloseAfterMillis`
* Use 10 seconds as default
Result:
WebSocket client handshaker to comply with RFC. Fixes#8883.
Motivation:
We did manually call HttpObjectDecoder.reset() in HttpObjectAggregator.handleOversizedMessage(...) which is incorrect and will prevent correct parsing of the next message.
Modifications:
- Remove call to HttpObjectDecoder.reset()
- Add unit test
Result:
Verify that we can correctly parse the next request after we rejected a request.
Motivation:
32563bfcc1 introduced a regression in which we did now not longer discard the messages after we handled an oversized message.
Modifications:
- Do not set aggregating to false after handleOversizedMessage is called
- Adjust unit tests to verify the behaviour is correct again.
Result:
Fixes https://github.com/netty/netty/issues/9007.
Motivation:
In 42742e233f we already added default methods to Channel*Handler and deprecated the Adapter classes to simplify the class hierarchy. With this change we go even further and merge everything into just ChannelHandler. This simplifies things even more in terms of class-hierarchy.
Modifications:
- Merge ChannelInboundHandler | ChannelOutboundHandler into ChannelHandler
- Adjust code to just use ChannelHandler
- Deprecate old interfaces.
Result:
Cleaner and simpler code in terms of class-hierarchy.
Motivation:
Add user possibility to skip the evaluation of certain web socket extension,
for example we can skip compression extension for messages that already compressed or very small and etc.
Modification:
This pull request is related with #5669
Result:
User can set to WebSocketClientExtensionHandshaker or WebSocketServerExtensionHandshaker a filter to skip the evaluation of certain extension.
Motivation:
According to the specification, the "Connection" header's syntax is:
"
The Connection header field's value has the following grammar:
Connection = 1#connection-option
connection-option = token
Connection options are case-insensitive.
"
https://tools.ietf.org/html/rfc7230#section-6.1
This means that Connection's value can have at least one element or
a comma separated list with elements
When calculating whether the connection can remain open,
HttpUtil.isKeepAlive(HttpMessage) should take this into account.
Modifications:
- Check for "close" and "keep-alive" in a comma separated list
- Add unit test
Result:
HttpUtil.isKeepAlive(HttpMessage) works correctly when "Connection: Upgrade, close"
Motivation:
As we now us java8 as minimum java version we can deprecate ChannelInboundHandlerAdapter / ChannelOutboundHandlerAdapter and just move the default implementations into the interfaces. This makes things a bit more flexible for the end-user and also simplifies the class-hierarchy.
Modifications:
- Mark ChannelInboundHandlerAdapter and ChannelOutboundHandlerAdapter as deprecated
- Add default implementations to ChannelInboundHandler / ChannelOutboundHandler
- Refactor our code to not use ChannelInboundHandlerAdapter / ChannelOutboundHandlerAdapter anymore
Result:
Cleanup class-hierarchy and make things a bit more flexible.
Motivation:
When HttpContentDecoder (and so HttpContentDecompressor) does not produce any message we need to make sure it calls ctx.read() if auto read is false to not stale.
Modifications:
- Keep track if we need to call ctx.read() or not
- Add unit test
Result:
Fixes https://github.com/netty/netty/issues/8915.
Motivation:
Netty is very widely used which can lead to a lot of pain when we break API / ABI. We should make use japicmp-maven-plugin during the build to verify we do not introduce breakage by mistake.
Modifications:
- Add japicmp-maven-plugin to the build process
- Fix a method signature change in HttpProxyHandler that was flagged as a possible problem.
Result:
Ensure no API/ABI breakage accour between releases.
Motivation:
WebSocketVersion can be simplified by directly store the string representation in the enum.
Modification:
Pass in the string representation when creating the enum.
Result:
Cleaner code.
Motivation:
We should not depend on the implementation detail of Unpooled.buffer(int) to allocate the exact size of backing byte[] as depending on the implementation it may return a buffer with a bigger backing array.
Modifications:
Explicit allocate the byte[] and wrap it in the ByteBuf. This way we are sure that ByteBuf.array() returns an byte[] which has the exact length and content we expect.
Result:
More correct and safe usage of ByteBuf.array()
Motivation:
Gracefully respond on bad client request.
We have a set of errors produced by Android 7.1.1/7.1.2 clients where both headers `HttpHeaderNames.SEC_WEBSOCKET_VERSION` and `HttpHeaderNames.ORIGIN` are not present. Absence of the first headers leads to WebSocketServerHandshaker00 be applied as a handshaker. However, null 2nd header causes
```
java.lang.NullPointerException: value
io.netty.util.internal.ObjectUtil.checkNotNull(ObjectUtil.java:33)
io.netty.handler.codec.DefaultHeaders.addObject(DefaultHeaders.java:327)
io.netty.handler.codec.http.DefaultHttpHeaders.add(DefaultHttpHeaders.java:123)
io.netty.handler.codec.http.websocketx.WebSocketServerHandshaker00.newHandshakeResponse(WebSocketServerHandshaker00.java:162)
```
Which causes connection close with unclear reason.
Modification:
Added null-check, and in case of null an appropriate WebSocketHandshakeException is thrown.
Result:
In case of null `HttpHeaderNames.ORIGIN` header a WebSocketHandshakeException is caught by WebSocketServerProtocolHandler which sends a graceful `BAD_REQUEST`.
Motivation:
Since Java 8, JDK has `java.util.Base64` that could replace custom netty implementation. It is faster (3x for this particular PR) and simpler.
Modifications:
Use Base64 directly.
Result:
```
Benchmark Mode Cnt Score Error Units
Base64Benchmark.base64New thrpt 6 7739181.025 ± 114230.467 ops/s
Base64Benchmark.base64Old thrpt 6 2689783.304 ± 454710.641 ops/s
```
Motivation:
When more than one connection header is present in h2c upgrade request, upgrade fails. This is to fix that.
Modification:
In HttpServerUpgradeHandler's upgrade() method, check whether any of the connection header value is upgrade, not just the first header value which might return a different value other than upgrade.
Result:
Fixes#8846.
With this PR, now when multiple connection headers are sent with the upgrade request, upgrade will not fail.
Motivation:
SPDY has been superseded by HTTP/2. Chrome has dropped support in 2016 and GFE no longer negociate it.
Modifications:
* drop codec
* drop examples
* drop constants from `ApplicationProtocolNames`
Result:
SPDY support dropped from Netty 5
Motivation:
We can replace some "hand-rolled" integer checks with our own static utility method to simplify the code.
Modifications:
Use methods provided by `ObjectUtil`.
Result:
Cleaner code and less duplication
Motivation:
We can use ThreadLocalRandom.current().nextInt() directly .
Motivation:
Use ThreadLocalRandom.current().nextInt() directly instead of (int) ThreadLocalRandom.current().nextDouble()
Result:
Less custom code to maintain
Motivation:
We can just use Objects.requireNonNull(...) as a replacement for ObjectUtil.checkNotNull(....)
Modifications:
- Use Objects.requireNonNull(...)
Result:
Less code to maintain.
Motivation
Implementations of MessageAggregator (HttpObjectAggregator in particular) may wish to
selectively aggrerage requests and responses on a case-by-case basis such as for example
only POST requests or only responses of a certain content-type.
Modifications
Adding a flag to MessageAggregator that toggles between true/false depending on if aggregation
is desired for the current message or not.
Result
Fixes#8772
Motivation:
We can re-use Files.readAllBytes(....) and so can remove our own implementation.
Modification:
Replaced custom readAllBytes with Files.readAllBytes
Result:
Less custom code.
Motivation:
We currently include two different cookie implementations, one is deprecated and one is not. We should remove the deprecated implentation.
Modifications:
Remove deprecated cookies classes.
Result:
Less code to maintain.
* HttpObjectDecoder ignores HTTP trailer header when empty line is received in seperate ByteBuf
Motivation:
When the empty line that termines the trailers was sent in a seperate ByteBuf we did ignore the previous parsed trailers and just returned none.
Modifications:
- Correct respect previous parsed trailers.
- Add unit test.
Result:
Fixes https://github.com/netty/netty/issues/8736
Motivation:
HttpHeaderDateFormat was replaced with DateFormatter many days ago and now can be easily removed.
Modification:
Remove deprecated class and related test / benchmark
Result:
Less code to maintain
Motivation:
In most cases, HttpMethod instance is built from the factory method and the same instance is taken for known Http Methods. So we can implement fast path for equals().
Modification:
Replace == checks with HttpMethod.equals;
Use this == o within HttpMethod.equals;
Replaced known new HttpMethod with HttpMethod.valueOf;
Result:
Comparisons should be a bit faster in some cases.
Motivation:
We can use lambdas now as we use Java8.
Modification:
use lambda function for all package, #8751 only migrate transport package.
Result:
Code cleanup.
Motivation:
As netty 4.x supported Java 6 we had various if statements to check for java versions < 8. We can remove these now.
Modification:
Remove unnecessary if statements that check for java versions < 8.
Result:
Cleanup code.
Motivation:
We need to update to a new checkstyle plugin to allow the usage of lambdas.
Modifications:
- Update to new plugin version.
- Fix checkstyle problems.
Result:
Be able to use checkstyle plugin which supports new Java syntax.
* Decouble EventLoop details from the IO handling for each transport to allow easy re-use of code and customization
Motiviation:
As today extending EventLoop implementations to add custom logic / metrics / instrumentations is only possible in a very limited way if at all. This is due the fact that most implementations are final or even package-private. That said even if these would be public there are the ability to do something useful with these is very limited as the IO processing and task processing are very tightly coupled. All of the mentioned things are a big pain point in netty 4.x and need improvement.
Modifications:
This changeset decoubled the IO processing logic from the task processing logic for the main transport (NIO, Epoll, KQueue) by introducing the concept of an IoHandler. The IoHandler itself is responsible to wait for IO readiness and process these IO events. The execution of the IoHandler itself is done by the SingleThreadEventLoop as part of its EventLoop processing. This allows to use the same EventLoopGroup (MultiThreadEventLoupGroup) for all the mentioned transports by just specify a different IoHandlerFactory during construction.
Beside this core API change this changeset also allows to easily extend SingleThreadEventExecutor / SingleThreadEventLoop to add custom logic to it which then can be reused by all the transports. The ideas are very similar to what is provided by ScheduledThreadPoolExecutor (that is part of the JDK). This allows for example things like:
* Adding instrumentation / metrics:
* how many Channels are registered on an SingleThreadEventLoop
* how many Channels were handled during the IO processing in an EventLoop run
* how many task were handled during the last EventLoop / EventExecutor run
* how many outstanding tasks we have
...
...
* Implementing custom strategies for choosing the next EventExecutor / EventLoop to use based on these metrics.
* Use different Promise / Future / ScheduledFuture implementations
* decorate Runnable / Callables when submitted to the EventExecutor / EventLoop
As a lot of functionalities are folded into the MultiThreadEventLoopGroup and SingleThreadEventLoopGroup this changeset also removes:
* AbstractEventLoop
* AbstractEventLoopGroup
* EventExecutorChooser
* EventExecutorChooserFactory
* DefaultEventLoopGroup
* DefaultEventExecutor
* DefaultEventExecutorGroup
Result:
Fixes https://github.com/netty/netty/issues/8514 .
Motivation:
Custom Netty ThreadLocalRandom and ThreadLocalRandomProvider classes are no longer needed and can be removed.
Modification:
Remove own ThreadLocalRandom
Result:
Less code to maintain
Motivation:
PlatformDependent.newConcurrentHashMap() is no longer needed so it could be easily removed and new ConcurrentHashMap<>() inlined instead of invoking PlatformDependent.newConcurrentHashMap().
Modification:
Use ConcurrentHashMap provided by the JDK directly.
Result:
Less code to maintain.
Motivation:
No need to initialize charsets from the string. We can take already allocated charset from StandardCharsets class.
Modification:
Replace Charset.forName("US-ASCII") with StandardCharsets.US_ASCII.
Removed Charset[] values() method and internal static variable as it was used only in tests.
Result:
Reuse what the JDK provides
Motivation:
We can use the diamond operator these days.
Modification:
Use diamond operator whenever possible.
Result:
More modern code and less boiler-plate.
Motivation:
Replace "if else" conditions with string switch. It is easier to read the code, for large "if else" constructions switch also could be faster.
Modification:
Replaced "if else" with a string switch.
Result:
Use new language features
Motivation:
Since Java 7 we can automatically close resources in try () construction.
Modification:
Changed all try catches in the code with autoclose try (resource)
Result:
Less boiler-plate
