SpringBoot升级报错:Failed to bind properties under 'logging.level'

错误详细信息:

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:) ~[spring-boot-2.0..RELEASE.jar:2.0..RELEASE]
    at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:) ~[spring-boot-2.0..RELEASE.jar:2.0..RELEASE]
    at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:) ~[spring-boot-2.0..RELEASE.jar:2.0..RELEASE]
    at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:) ~[spring-boot-2.0..RELEASE.jar:2.0..RELEASE]
    at org.springframework.boot.context.logging.LoggingApplicationListener.setLogLevels(LoggingApplicationListener.java:) ~[spring-boot-2.0..RELEASE.jar:2.0..RELEASE]
    at org.springframework.boot.context.logging.LoggingApplicationListener.initializeFinalLoggingLevels(LoggingApplicationListener.java:) ~[spring-boot-2.0..RELEASE.jar:2.0..RELEASE]
    at org.springframework.boot.context.logging.LoggingApplicationListener.initialize(LoggingApplicationListener.java:) ~[spring-boot-2.0..RELEASE.jar:2.0..RELEASE]
    at org.springframework.boot.context.logging.LoggingApplicationListener.onApplicationEnvironmentPreparedEvent(LoggingApplicationListener.java:) ~[spring-boot-2.0..RELEASE.jar:2.0..RELEASE]
    at org.springframework.boot.context.logging.LoggingApplicationListener.onApplicationEvent(LoggingApplicationListener.java:) ~[spring-boot-2.0..RELEASE.jar:2.0..RELEASE]
    at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:) ~[spring-context-5.0..RELEASE.jar:5.0..RELEASE]
    at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:) ~[spring-context-5.0..RELEASE.jar:5.0..RELEASE]
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:) ~[spring-context-5.0..RELEASE.jar:5.0..RELEASE]
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:) ~[spring-context-5.0..RELEASE.jar:5.0..RELEASE]
    at org.springframework.boot.context.event.EventPublishingRunListener.environmentPrepared(EventPublishingRunListener.java:) ~[spring-boot-2.0..RELEASE.jar:2.0..RELEASE]
    at org.springframework.boot.SpringApplicationRunListeners.environmentPrepared(SpringApplicationRunListeners.java:) ~[spring-boot-2.0..RELEASE.jar:2.0..RELEASE]
    at org.springframework.boot.SpringApplication.prepareEnvironment(SpringApplication.java:) ~[spring-boot-2.0..RELEASE.jar:2.0..RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:) ~[spring-boot-2.0..RELEASE.jar:2.0..RELEASE]
    at com.acs.springboot.AcsAdminApplication.main(AcsAdminApplication.java:) [classes/:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_152]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:) ~[na:1.8.0_152]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:) ~[na:1.8.0_152]
    at java.lang.reflect.Method.invoke(Method.java:) ~[na:1.8.0_152]
    at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:) [spring-boot-devtools-2.0..RELEASE.jar:2.0..RELEASE]
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:) ~[spring-core-5.0..RELEASE.jar:5.0..RELEASE]
    at org.springframework.core.convert.support.GenericConversionService.convert(GenericConversionService.java:) ~[spring-core-5.0..RELEASE.jar:5.0..RELEASE]
    at org.springframework.boot.context.properties.bind.BindConverter$CompositeConversionService.convert(BindConverter.java:) ~[spring-boot-2.0..RELEASE.jar:2.0..RELEASE]
    at org.springframework.boot.context.properties.bind.BindConverter.convert(BindConverter.java:) ~[spring-boot-2.0..RELEASE.jar:2.0..RELEASE]
    at org.springframework.boot.context.properties.bind.BindConverter.convert(BindConverter.java:) ~[spring-boot-2.0..RELEASE.jar:2.0..RELEASE]
    at org.springframework.boot.context.properties.bind.MapBinder.bindAggregate(MapBinder.java:) ~[spring-boot-2.0..RELEASE.jar:2.0..RELEASE]
    at org.springframework.boot.context.properties.bind.AggregateBinder.bind(AggregateBinder.java:) ~[spring-boot-2.0..RELEASE.jar:2.0..RELEASE]
    at org.springframework.boot.context.properties.bind.Binder.lambda$bindAggregate$(Binder.java:) ~[spring-boot-2.0..RELEASE.jar:2.0..RELEASE]
    at org.springframework.boot.context.properties.bind.Binder$Context.withIncreasedDepth(Binder.java:) ~[spring-boot-2.0..RELEASE.jar:2.0..RELEASE]
    at org.springframework.boot.context.properties.bind.Binder$Context.access$(Binder.java:) ~[spring-boot-2.0..RELEASE.jar:2.0..RELEASE]
    at org.springframework.boot.context.properties.bind.Binder.bindAggregate(Binder.java:) ~[spring-boot-2.0..RELEASE.jar:2.0..RELEASE]
    at org.springframework.boot.context.properties.bind.Binder.bindObject(Binder.java:) ~[spring-boot-2.0..RELEASE.jar:2.0..RELEASE]
    at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:) ~[spring-boot-2.0..RELEASE.jar:2.0..RELEASE]
    ...  common frames omitted

抓住关键信息:

Failed to bind properties under 'logging.level'

错误产生背景：
SpringBoot1.5.9升级为2.0.7版本。

错误原因分析:
是因为SpringBoot2.0以上版本日志需要指定包路径才行。

解决办法(修改application.yml配置文件):

原文件关键内容如下:

logging:
  level: warn

将其改为(指定包路径):

logging:
   com.blog.springboot: WARN

com.blog.springboot是我个人博客的启动类，你们可以将其改为你自己的即可。
最后问题迎刃而解。