SpringBoot报错：Failed to load ApplicationContext( Failed to bind properties under 'logging.level')

引起条件：
SpringBoot2.0下yml文件配置SLF4j日志输出日志级别

logging:
  level: debug

解决方法：

1. 指定系统包路径

   logging:
       root: debug
   

2. 指定自己的包目录

   logging:
       com.tuyrk.test: debug
   

相关资料：
https://docs.spring.io/spring-boot/docs/2.1.1.RELEASE/reference/htmlsingle/#boot-features-custom-log-levels

通过使用logging.level，所有受支持的日志记录系统都可以在Spring环境中(例如，在application.properties中)设置记录器级别。
<logger-name>=<level>其中的Level是跟踪、调试、信息、警告、错误、致命或关闭级别之一。
可以使用logging.level.root配置根记录器。

下面的示例显示了应用程序中潜在的日志记录设置：

logging.level.root=WARN
logging.level.org.springframework.web=DEBUG
logging.level.org.hibernate=ERROR

java.lang.IllegalStateException: Failed to load ApplicationContext

	at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:125)
	at org.springframework.test.context.support.DefaultTestContext.getApplicationContext(DefaultTestContext.java:108)
	at org.springframework.test.context.web.ServletTestExecutionListener.setUpRequestContextIfNecessary(ServletTestExecutionListener.java:190)
	at org.springframework.test.context.web.ServletTestExecutionListener.prepareTestInstance(ServletTestExecutionListener.java:132)
	at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:246)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:227)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:289)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:291)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:246)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:97)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
	at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
	at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:190)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
	at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
	at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
	at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: org.springframework.boot.context.properties.bind.BindException: Failed to bind properties under 'logging.level' to java.util.Map<java.lang.String, java.lang.String>
	at org.springframework.boot.context.properties.bind.Binder.handleBindError(Binder.java:249)
	at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:225)
	at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:208)
	at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:177)
	at org.springframework.boot.context.logging.LoggingApplicationListener.setLogLevels(LoggingApplicationListener.java:338)
	at org.springframework.boot.context.logging.LoggingApplicationListener.initializeFinalLoggingLevels(LoggingApplicationListener.java:319)
	at org.springframework.boot.context.logging.LoggingApplicationListener.initialize(LoggingApplicationListener.java:267)
	at org.springframework.boot.context.logging.LoggingApplicationListener.onApplicationEnvironmentPreparedEvent(LoggingApplicationListener.java:229)
	at org.springframework.boot.context.logging.LoggingApplicationListener.onApplicationEvent(LoggingApplicationListener.java:202)
	at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172)
	at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165)
	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139)
	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:127)
	at org.springframework.boot.context.event.EventPublishingRunListener.environmentPrepared(EventPublishingRunListener.java:75)
	at org.springframework.boot.SpringApplicationRunListeners.environmentPrepared(SpringApplicationRunListeners.java:54)
	at org.springframework.boot.SpringApplication.prepareEnvironment(SpringApplication.java:347)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:306)
	at org.springframework.boot.test.context.SpringBootContextLoader.loadContext(SpringBootContextLoader.java:127)
	at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContextInternal(DefaultCacheAwareContextLoaderDelegate.java:99)
	at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:117)
	... 24 more
Caused by: org.springframework.core.convert.ConverterNotFoundException: No converter found capable of converting from type [java.lang.String] to type [java.util.Map<java.lang.String, java.lang.String>]
	at org.springframework.core.convert.support.GenericConversionService.handleConverterNotFound(GenericConversionService.java:321)
	at org.springframework.core.convert.support.GenericConversionService.convert(GenericConversionService.java:194)
	at org.springframework.boot.context.properties.bind.BindConverter$CompositeConversionService.convert(BindConverter.java:177)
	at org.springframework.boot.context.properties.bind.BindConverter.convert(BindConverter.java:98)
	at org.springframework.boot.context.properties.bind.BindConverter.convert(BindConverter.java:90)
	at org.springframework.boot.context.properties.bind.MapBinder.bindAggregate(MapBinder.java:65)
	at org.springframework.boot.context.properties.bind.AggregateBinder.bind(AggregateBinder.java:58)
	at org.springframework.boot.context.properties.bind.Binder.lambda$bindAggregate$2(Binder.java:304)
	at org.springframework.boot.context.properties.bind.Binder$Context.withIncreasedDepth(Binder.java:448)
	at org.springframework.boot.context.properties.bind.Binder$Context.access$100(Binder.java:388)
	at org.springframework.boot.context.properties.bind.Binder.bindAggregate(Binder.java:303)
	at org.springframework.boot.context.properties.bind.Binder.bindObject(Binder.java:261)
	at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:220)
	... 42 more