merge dubbox core features from dangdang:

[terrymanu]

What is the purpose of the change

merge dubbox core features

Brief changelog

1. rest protocol
2. kryo & fst serialization
3. embed tomcat

[CLAassistant]

All committers have signed the CLA.

[chickenlj]

We have been concerned about the awesome features in dubbox, thanks for making this contribution.
Are you an official partner of dubbox? Maybe we can issue an announcement separately, so both users of dubbo and dubbox can notice this change. We can continue to promote these features on the dubbo project.

[terrymanu]

@chickenlj Hello chickenlj. Yes, I am dubbox's official owner from dangdang. Thanks for alibaba open source dubbo, it is really a wonderful project.
It is a good idea to issue an announcement separately after dubbo merge dubbox.

[zhangruhong]

火钳刘明（Leave a message/comment before it becomes a top/hot tweet.）

[chickenlj]

We decide to merge this part after version 2.5.8, which will be in the next few days.

[linyongfu2013]

so it should be coming soon ? looking forward to it .

[lovepoem]

#764

[kirbylynx]

Really looking forward for 2.5.8.
As far as I know, it would include two exciting features, REST/kryo/FST serialization, and spring boot starter support.

[fanlei1988]

真是个好消息，不过，我还是希望dubbo 同时也可以支持SpringMVC 的Rest实现， 因为我感觉dubbox 和swagger 兼容并不是很好，并且并不支持其他容器吧

[nmyphp]

太好了！作为当当员工，之前一直使用dubbox，得知dubbo重新维护了，第一个问题就是dubbox是否会继续更新，这下好了。会一直关注

[zuohl]

怎么pr还不合并,,还是说准备自己实现一套..

[codecov-io]

Codecov Report

Merging #1001 into master will decrease coverage by 0.26%.
The diff coverage is 20.4%.

@@            Coverage Diff             @@
##           master    #1001      +/-   ##
==========================================
- Coverage   27.68%   27.42%   -0.27%     
==========================================
  Files         789      824      +35     
  Lines       41577    42297     +720     
  Branches     8476     8556      +80     
==========================================
+ Hits        11510    11598      +88     
- Misses      28021    28636     +615     
- Partials     2046     2063      +17

Impacted Files	Coverage Δ
.../main/java/com/alibaba/dubbo/common/Constants.java	88.88% <ø> (ø)	⬆️
...dubbo/rpc/protocol/rest/support/LoggingFilter.java	0% <0%> (ø)
...a/dubbo/remoting/http/tomcat/TomcatHttpServer.java	0% <0%> (ø)
...java/com/alibaba/dubbo/rpc/ServiceClassHolder.java	0% <0%> (ø)
...libaba/dubbo/rpc/protocol/rest/UndertowServer.java	0% <0%> (ø)
...alibaba/dubbo/rpc/protocol/rest/SunHttpServer.java	0% <0%> (ø)
...common/serialize/support/fst/FstSerialization.java	0% <0%> (ø)
...a/dubbo/remoting/exchange/codec/ExchangeCodec.java	66.66% <0%> (-1.3%)	⬇️
...om/alibaba/dubbo/rpc/protocol/rest/TjwsServer.java	0% <0%> (ø)
...rc/main/java/com/alibaba/dubbo/rpc/RpcContext.java	27.04% <0%> (-1.07%)	⬇️
... and 82 more

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[chickenlj]

I decide to merge this PR to the 2.6 branch first, and do some adjust, e.g, upgrade dependency version.

[FredGoo]

持续关注中

[chickenlj]

The core features of this PR have been published in 2.6.0

[Lovelcp]

赞赞赞

[leontius]

关注中。

[PepperYan]

等了这么久终于合并了!

[zhenyajiang]

you should metion about what's the version of kyro and FST dependency. it cause the problem. Caused by: java.lang.NoClassDefFoundError: com/esotericsoftware/kryo/pool/KryoFactory.
anyway, tks a lot for dangdang and alibaba open source.

[superleo-cn]

我在kryo基础上还加入了twitter chill，支持Java的同时，还能比较完美的支持Scala，让Scala童鞋也能享受dubbo直接支持数据类型的快感，如何分享呢？

[luzhzhsoft]

有没有rest 的demo 或者相关的文档介绍呐？按照当当的demo 跑不起来。好像是kryo 版本的问题

[nmyphp]

@luzhzhsoft可以参考一下这篇CSDN博客：https://blog.csdn.net/nmyphp/article/details/79174225

[lovepoem]

我在kryo基础上还加入了twitter chill，支持Java的同时，还能比较完美的支持Scala，让Scala童鞋也能享受dubbo直接支持数据类型的快感，如何分享

@superleo-cn ,can you give your code repository?

[ldcsaa]

@lovepoem 现在的dubbo与当当的dubbox（2.8.4）应该是不兼容的吧？dubbox修改了dubbo的序列化协议。
\dubbo\rpc\protocol\dubbo\DubboCodec.java 对比：

[lovepoem]

\dubbo\rpc\protocol\dubbo\DubboCodec.java 对比：
你用的什么协议？ 如果是默认的hessian协议，还是支持的

[zhangruhong]

这是我的自动回复邮件。 This is an automatic reply of the email system. 您好，你的邮件我己收到，我会尽快处理，谢谢！I have received your E-mail, and I will reply as soon as possible. Thank you!