在Springboot 2中，你可以像这样用环境变量设置根日志级别:

logging.level.root=DEBUG

或者你可以像这样为包设置特定的日志记录:

logging.level.my.package.name=TRACE

in spring boot project we can write logging.level.root=WARN but here problem is, we have to restart again even we added devtools dependency, in property file if we are modified any value will not autodetectable, for this limitation i came to know the solution i,e we can add actuator in pom.xml and pass the logger level as below shown in postman client in url bar http://localhost:8080/loggers/ROOT or http://localhost:8080/loggers/com.mycompany and in the body you can pass the json format like below

{
  "configuredLevel": "WARN"
}

在我当前的配置中，我在应用程序中定义了它。Yaml是这样的:

logging:
  level:
    ROOT: TRACE

我正在使用spring-boot:2.2.0.RELEASE。您可以像这样定义任何应该具有TRACE级别的包。

如果你想设置更多的细节，请添加一个日志配置文件名“logback.xml”或“logback-spring.xml”。

在你的应用中。属性文件，输入如下:

logging.config: classpath:logback-spring.xml

在loback-spring.xml中，像这样输入:

    <?xml version="1.0" encoding="UTF-8"?>
    <configuration>
        <include resource="org/springframework/boot/logging/logback/base.xml"/>

        <appender name="ROOT_APPENDER" class="ch.qos.logback.core.rolling.RollingFileAppender">

            <filter class="ch.qos.logback.classic.filter.LevelFilter">
                <level>INFO</level>
                <onMatch>ACCEPT</onMatch>
                <onMismatch>DENY</onMismatch>
            </filter>

            <file>sys.log</file>

            <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">


                <fileNamePattern>${LOG_DIR}/${SYSTEM_NAME}/system.%d{yyyy-MM-dd}.%i.log</fileNamePattern>

                <timeBasedFileNamingAndTriggeringPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
                    <maxFileSize>500MB</maxFileSize>
                </timeBasedFileNamingAndTriggeringPolicy>
            </rollingPolicy>

            <encoder>
                <pattern>%-20(%d{yyy-MM-dd HH:mm:ss.SSS} [%X{requestId}]) %-5level - %logger{80} - %msg%n
                </pattern>
            </encoder>
        </appender>


        <appender name="BUSINESS_APPENDER" class="ch.qos.logback.core.rolling.RollingFileAppender">
            <filter class="ch.qos.logback.classic.filter.LevelFilter">
                <level>TRACE</level>
                <onMatch>ACCEPT</onMatch>
                <onMismatch>DENY</onMismatch>
            </filter>

            <file>business.log</file>

            <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">

                <fileNamePattern>${LOG_DIR}/${SYSTEM_NAME}/business.%d{yyyy-MM-dd}.%i.log</fileNamePattern>

                <timeBasedFileNamingAndTriggeringPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
                    <maxFileSize>500MB</maxFileSize>
                </timeBasedFileNamingAndTriggeringPolicy>
            </rollingPolicy>

            <encoder>
                <pattern>%-20(%d{yyy-MM-dd HH:mm:ss.SSS} [%X{requestId}]) %-5level - %logger{80} - %msg%n
                </pattern>
            </encoder>
        </appender>


        <logger name="{project-package-name}" level="TRACE">
            <appender-ref ref="BUSINESS_APPENDER" />
        </logger>

        <root level="INFO">
            <appender-ref ref="ROOT_APPENDER" />
        </root>

    </configuration>

假设应用程序的包名为com.company.myproject。然后，您可以在应用程序中为项目中的类设置日志级别，如下所示。属性文件

loging.level.com.company.myproject = DEBUG

loging.level.org.springframework.web = DEBUG和loging.level.org.hibernate = DEBUG将仅为Spring框架web和Hibernate的类设置日志级别。

用于设置日志文件位置使用

伐木。文件= /home/ubuntu/myproject

记录:官方文档，如Spring Boot v1.2.0。RELEASE和Spring v4.1.3 RELEASE:

If the only change you need to make to logging is to set the levels of various loggers then you can do that in application.properties using the "logging.level" prefix, e.g. logging.level.org.springframework.web: DEBUG logging.level.org.hibernate: ERROR You can also set the location of a file to log to (in addition to the console) using "logging.file". To configure the more fine-grained settings of a logging system you need to use the native configuration format supported by the LoggingSystem in question. By default Spring Boot picks up the native configuration from its default location for the system (e.g. classpath:logback.xml for Logback), but you can set the location of the config file using the "logging.config" property.