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来源： case-ognl-update-logger-level
案例: 动态更新应用Logger Level
在这个案例里，动态修改应用的Logger Level。
查找UserController的ClassLoader
sc -d com.example.demo.arthas.user.UserController | grep classLoaderHash
$ sc -d com.example.demo.arthas.user.UserController | grep classLoaderHash
classLoaderHash 1be6f5c3
用ognl获取logger
ognl –classLoaderClass org.springframework.boot.loader.LaunchedURLClassLoader ‘@com.example.demo.arthas.user.UserController@logger’
$ ognl --classLoaderClass org.springframework.boot.loader.LaunchedURLClassLoader '@com.example.demo.arthas.user.UserController@logger'
@Logger[
serialVersionUID=@Long[5454405123156820674],
FQCN=@String[ch.qos.logback.classic.Logger],
name=@String[com.example.demo.arthas.user.UserController],
level=null,
effectiveLevelInt=@Integer[20000],
parent=@Logger[Logger[com.example.demo.arthas.user]],
childrenList=null,
aai=null,
additive=@Boolean[true],
loggerContext=@LoggerContext[ch.qos.logback.classic.LoggerContext[default]],
]
可以知道UserController@logger实际使用的是logback。可以看到level=null，则说明实际最终的level是从root logger里来的。
单独设置UserController的logger level
ognl –classLoaderClass org.springframework.boot.loader.LaunchedURLClassLoader ‘@com.example.demo.arthas.user.UserController@logger.setLevel(@ch.qos.logback.classic.Level@DEBUG)’
再次获取UserController@logger，可以发现已经是DEBUG了：
ognl –classLoaderClass org.springframework.boot.loader.LaunchedURLClassLoader ‘@com.example.demo.arthas.user.UserController@logger’
$ ognl --classLoaderClass org.springframework.boot.loader.LaunchedURLClassLoader '@com.example.demo.arthas.user.UserController@logger'
@Logger[
serialVersionUID=@Long[5454405123156820674],
FQCN=@String[ch.qos.logback.classic.Logger],
name=@String[com.example.demo.arthas.user.UserController],
level=@Level[DEBUG],
effectiveLevelInt=@Integer[10000],
parent=@Logger[Logger[com.example.demo.arthas.user]],
childrenList=null,
aai=null,
additive=@Boolean[true],
loggerContext=@LoggerContext[ch.qos.logback.classic.LoggerContext[default]],
]
修改logback的全局logger level
ognl –classLoaderClass org.springframework.boot.loader.LaunchedURLClassLoader ‘@org.slf4j.LoggerFactory@getLogger(“root”).setLevel(@ch.qos.logback.classic.Level@DEBUG)’
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