Dubbo 2.6.x/2.7.x - Spring Framework 升级需求 - Spring framework 4.3.x upgrade to 5.2.x is expected

[Chenjp]

Dubbo 2.6.x - Spring framework upgrade

• Spring framework Lifecycle Policy

According spring official announcement, spring framework 4.3.x is the last feature branch of the 4th generation. It comes with extended maintenance until April 2020 and critical patches even beyond that point. 4.3.x will reach its official ** EOL (end-of-life) on December 31st, 2020 **.

Environment

• Dubbo version: 2.6.x

Expected Result

Spring framework 4.3.x -> 5.2.x is expected after December 31st, 2020.

[Chenjp]

@chickenlj @mercyblitz could add this request to 2.6.10 milestone?