1.pom文件添加

<!-- 集成Log4j2日志 -->
         <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-logging</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-log4j2</artifactId>
        </dependency>

如果你的其他依赖里面依赖了logback-classic，项目会报如下错误，将其依赖的logback-classic排除掉即可。

SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/Users/tongqinyuan/.m2/repository/org/slf4j/slf4j-log4j12/1.7.25/slf4j-log4j12-1.7.25.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/Users/tongqinyuan/.m2/repository/ch/qos/logback/logback-classic/1.2.3/logback-classic-1.2.3.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Actual binding is of type [org.slf4j.impl.Log4jLoggerFactory]
Exception in thread "main" java.lang.IllegalArgumentException: LoggerFactory is not a Logback LoggerContext but Logback is on the classpath. Either remove Logback or the competing implementation (class org.slf4j.impl.Log4jLoggerFactory loaded from file:/Users/tongqinyuan/.m2/repository/org/slf4j/slf4j-log4j12/1.7.25/slf4j-log4j12-1.7.25.jar). If you are using WebLogic you will need to add 'org.slf4j' to prefer-application-packages in WEB-INF/weblogic.xml: org.slf4j.impl.Log4jLoggerFactory

这里推荐在idea里安装maven help 插件，在pom.xml文件下点击dependency Analyzer分析查看冲突的包

help.png

2.application.properties文件添加

logging.config=classpath:log4j2.xml

3.resources文件夹下编辑log4j2.xml文件（与application.properties放在同级目录）

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="INFO">

    <Appenders>
        <Console name="STDOUT" target="SYSTEM_OUT">
            <!-- <PatternLayout pattern="%d %-5p [%t] %C{2} (%F:%L) - %m%n"/> -->
            <PatternLayout pattern=".%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] [%file:%line]
                %-5level %logger{36} - %msg %n"/>
        </Console>

        <RollingFile name="RollingFile" fileName="logs/app.log"
                     filePattern="logs/$${date:yyyy-MM}/app-%d{MM-dd-yyyy}-%i.log">
            <PatternLayout>
                <Pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] [%file:%line] %-5level %logger{35} - %msg %n</Pattern>
            </PatternLayout>
            <Policies>
                <TimeBasedTriggeringPolicy />
                <SizeBasedTriggeringPolicy size="102400KB"/>
            </Policies>
            <DefaultRolloverStrategy fileIndex="max" max="2"/>
        </RollingFile>
    </Appenders>
    <Loggers>

        <Root level="info">
            <AppenderRef ref="STDOUT"/>
            <AppenderRef ref="RollingFile"/>
        </Root>
    </Loggers>

</Configuration>