Polish logging SPI related code and add general JUL adapter for Logger SPI

[sczyh30]

Signed-off-by: Eric Zhao [email protected]

Describe what this PR does / why we need it

Polish logging SPI related code and add general JUL adapter for Logger SPI.

Does this pull request fix one issue?

Related to #757

Describe how you did it

• Move the legacy JUL methods from LogBase to BaseJulLogger.
• Add a JavaLoggingAdapter as the general JUL adapter for the Logger SPI, which makes it convenient to use (as the default logger).
• Add LoggerSpiProvider to resolve Logger SPI.
• Polish the logback demo.

Describe how to verify it

Run the test cases and demo.

Special notes for reviews

Be careful with circular class dependency and error handling in static block.

[sczyh30]

Some of the log contents have not updated to the universal placeholder {} yet. I'll submit a new PR to do this.

[codecov-io]

Codecov Report

Merging #1338 into master will increase coverage by 0.27%.
The diff coverage is 43.35%.

@@             Coverage Diff              @@
##             master    #1338      +/-   ##
============================================
+ Coverage     42.47%   42.75%   +0.27%     
- Complexity     1639     1647       +8     
============================================
  Files           364      363       -1     
  Lines         10502    10484      -18     
  Branches       1408     1405       -3     
============================================
+ Hits           4461     4482      +21     
+ Misses         5485     5446      -39     
  Partials        556      556

Impacted Files	Coverage Δ	Complexity Δ
...com/alibaba/csp/sentinel/log/jul/CspFormatter.java	100% <ø> (ø)	4 <0> (?)
...ibaba/csp/sentinel/log/jul/DateFileLogHandler.java	57.57% <ø> (ø)	7 <0> (?)
.../alibaba/csp/sentinel/log/jul/FormattingTuple.java	81.81% <ø> (ø)	4 <0> (?)
...n/java/com/alibaba/csp/sentinel/log/jul/Level.java	100% <ø> (ø)	2 <0> (?)
...m/alibaba/csp/sentinel/log/jul/ConsoleHandler.java	45.45% <ø> (ø)	3 <0> (?)
...alibaba/csp/sentinel/log/jul/MessageFormatter.java	20.37% <ø> (ø)	12 <0> (?)
...com/alibaba/csp/sentinel/log/CommandCenterLog.java	0% <0%> (ø)	0 <0> (ø)	⬇️
.../java/com/alibaba/csp/sentinel/util/SpiLoader.java	16.32% <0%> (ø)	4 <0> (ø)	⬇️
...alibaba/csp/sentinel/node/metric/MetricWriter.java	58.57% <100%> (ø)	21 <0> (ø)	⬇️
...om/alibaba/csp/sentinel/log/LoggerSpiProvider.java	31.81% <31.81%> (ø)	3 <3> (?)
... and 11 more

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[cdfive]

The dependency seems not used in demo, is it redundant

[sczyh30]

Actually I'm planning to move the CommandCenterLog to sentinel-transport-common, as it's only used in transport command centers. This will be done in another PR, but the dependency could be reserved :)

[cdfive]

OK, got it. Now LogBase is not a parent class, maybe another class name is better, like LogConfig or sth else. Besides, I found that the config parameter which can be customized by user is scattered in different classes(by global seaching "csp.sentinel." in sentinel-core module), if it is better put them into one config class, to make config clearly and convenient to found. And this may need careful consideration and discussion, and I think we can do it in the future.

[sczyh30]

Good idea. We may improve this later, but be careful of the compatibility. We could create an umbrella issue to discuss it :)

[cdfive]

LGTM! Nice work, good code and continuous polishing, now the log package is more refined and meanwhile easier to read.