Signed-off-by: Eric Zhao <sczyh16@gmail.com>

* Also polish related complete callbacks

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

- which may lead to IllegalMonitorStateException in unlock() when unchecked error occurs during lock()

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

* Improve log info in SpiLoader, improve comment and test case
* Use error level in catch block, init ArrayList with capacity and improve add item to list

* Note that this is only a temporary solution.

* Make slots loaded by SPI, mark all slots with @SpiOrder from -10000 to -1000, improve comment
* Reserve gateway and param slot chain builder (just extends DefaultSlotChainBuilder) and mark them as @Deprecated

* Supplement missing javax.annotation-api to sentinel-cluster-server-envoy-rls and sentinel-demo-zuul2-gateway
* Upgrade mockito-core to 2.28.2 (up to date)

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

* Polish placeholders in logging content to "{}"

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

* 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.

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

- also add demo for Zuul 2.x adapter

* Following discussions in https://github.com/alibaba/Sentinel/issues/1315

* Fix InMemoryMetricsRepository can't keep the last five minutes metrics data problem and Improve read-write performance
* Use TimeUtil.currentTimeMillis() replace System.currentTimeMillis() for better performance

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

* There are two types of logger for command center and common modules specified by  annotation of `LogTarget`
* Add implementing examples in `sentinel-demo/sentinel-demo-log-logback`
* All implementations should support placeholder '{}'

* Better compatibility of the dashboard to legacy and new sentinel-transport-simple-http (on Content-Type header), related to #1207