1. pom.xml中springboot版本依赖
<!--Spring-boot中去掉logback的依赖-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<exclusions>
<exclusion>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-logging</artifactId>
</exclusion>
</exclusions>
</dependency>

<!--日志-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-log4j2</artifactId>
</dependency>

<!--数据库连接池-->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
<version>1.1.6</version>
</dependency>

<!--其他依赖-->

2. log4j2.xml文件中的日志配置(完整，可直接拷贝使用)
<?xml version="1.0" encoding="UTF-8"?>
<configuration status="OFF">
<appenders>

<Console name="Console" target="SYSTEM_OUT">
<!--只接受程序中DEBUG级别的日志进行处理-->
<ThresholdFilter level="DEBUG" onMatch="ACCEPT" onMismatch="DENY"/>
<PatternLayout pattern="[%d{HH:mm:ss.SSS}] %-5level %class{36} %L %M - %msg%xEx%n"/>
</Console>

<!--处理DEBUG级别的日志，并把该日志放到logs/debug.log文件中-->
<!--打印出DEBUG级别日志，每次大小超过size，则这size大小的日志会自动存入按年份-月份建立的文件夹下面并进行压缩，作为存档-->
<RollingFile name="RollingFileDebug" fileName="./logs/debug.log"
filePattern="logs/$${date:yyyy-MM}/debug-%d{yyyy-MM-dd}-%i.log.gz">
<Filters>
<ThresholdFilter level="DEBUG"/>
<ThresholdFilter level="INFO" onMatch="DENY" onMismatch="NEUTRAL"/>
</Filters>
<PatternLayout
pattern="[%d{yyyy-MM-dd HH:mm:ss}] %-5level %class{36} %L %M - %msg%xEx%n"/>
<Policies>
<SizeBasedTriggeringPolicy size="500 MB"/>
<TimeBasedTriggeringPolicy/>
</Policies>
</RollingFile>

<!--处理INFO级别的日志，并把该日志放到logs/info.log文件中-->
<RollingFile name="RollingFileInfo" fileName="./logs/info.log"
filePattern="logs/$${date:yyyy-MM}/info-%d{yyyy-MM-dd}-%i.log.gz">
<Filters>
<!--只接受INFO级别的日志，其余的全部拒绝处理-->
<ThresholdFilter level="INFO"/>
<ThresholdFilter level="WARN" onMatch="DENY" onMismatch="NEUTRAL"/>
</Filters>
<PatternLayout
pattern="[%d{yyyy-MM-dd HH:mm:ss}] %-5level %class{36} %L %M - %msg%xEx%n"/>
<Policies>
<SizeBasedTriggeringPolicy size="500 MB"/>
<TimeBasedTriggeringPolicy/>
</Policies>
</RollingFile>

<!--处理WARN级别的日志，并把该日志放到logs/warn.log文件中-->
<RollingFile name="RollingFileWarn" fileName="./logs/warn.log"
filePattern="logs/$${date:yyyy-MM}/warn-%d{yyyy-MM-dd}-%i.log.gz">
<Filters>
<ThresholdFilter level="WARN"/>
<ThresholdFilter level="ERROR" onMatch="DENY" onMismatch="NEUTRAL"/>
</Filters>
<PatternLayout
pattern="[%d{yyyy-MM-dd HH:mm:ss}] %-5level %class{36} %L %M - %msg%xEx%n"/>
<Policies>
<SizeBasedTriggeringPolicy size="500 MB"/>
<TimeBasedTriggeringPolicy/>
</Policies>
</RollingFile>

<!--处理error级别的日志，并把该日志放到logs/error.log文件中-->
<RollingFile name="RollingFileError" fileName="./logs/error.log"
filePattern="logs/$${date:yyyy-MM}/error-%d{yyyy-MM-dd}-%i.log.gz">
<ThresholdFilter level="ERROR"/>
<PatternLayout
pattern="[%d{yyyy-MM-dd HH:mm:ss}] %-5level %class{36} %L %M - %msg%xEx%n"/>
<Policies>
<SizeBasedTriggeringPolicy size="500 MB"/>
<TimeBasedTriggeringPolicy/>
</Policies>
</RollingFile>

<!--druid的日志记录追加器-->
<RollingFile name="druidSqlRollingFile" fileName="./logs/druid-sql.log"
filePattern="logs/$${date:yyyy-MM}/api-%d{yyyy-MM-dd}-%i.log.gz">
<PatternLayout pattern="[%d{yyyy-MM-dd HH:mm:ss}] %-5level %L %M - %msg%xEx%n"/>
<Policies>
<SizeBasedTriggeringPolicy size="500 MB"/>
<TimeBasedTriggeringPolicy/>
</Policies>
</RollingFile>
</appenders>

<loggers>
<root level="DEBUG">
<appender-ref ref="Console"/>
<appender-ref ref="RollingFileInfo"/>
<appender-ref ref="RollingFileWarn"/>
<appender-ref ref="RollingFileError"/>
<appender-ref ref="RollingFileDebug"/>
</root>

<!--记录druid-sql的记录-->
<logger name="druid.sql.Statement" level="debug" additivity="false">
<appender-ref ref="druidSqlRollingFile"/>
</logger>
<logger name="druid.sql.Statement" level="debug" additivity="false">
<appender-ref ref="druidSqlRollingFile"/>
</logger>

<!--log4j2 自带过滤日志-->
<Logger name="org.apache.catalina.startup.DigesterFactory" level="error" />
<Logger name="org.apache.catalina.util.LifecycleBase" level="error" />
<Logger name="org.apache.coyote.http11.Http11NioProtocol" level="warn" />
<logger name="org.apache.sshd.common.util.SecurityUtils" level="warn"/>
<Logger name="org.apache.tomcat.util.net.NioSelectorPool" level="warn" />
<Logger name="org.crsh.plugin" level="warn" />
<logger name="org.crsh.ssh" level="warn"/>
<Logger name="org.eclipse.jetty.util.component.AbstractLifeCycle" level="error" />
<Logger name="org.hibernate.validator.internal.util.Version" level="warn" />
<logger name="org.springframework.boot.actuate.autoconfigure.CrshAutoConfiguration" level="warn"/>
<logger name="org.springframework.boot.actuate.endpoint.jmx" level="warn"/>
<logger name="org.thymeleaf" level="warn"/>
</loggers>
</configuration>

3. 配置application.properties
# 配置日志输出
spring.datasource.druid.filter.slf4j.enabled=true
spring.datasource.druid.filter.slf4j.statement-create-after-log-enabled=false
spring.datasource.druid.filter.slf4j.statement-close-after-log-enabled=false
spring.datasource.druid.filter.slf4j.result-set-open-after-log-enabled=false
spring.datasource.druid.filter.slf4j.result-set-close-after-log-enabled=false

4. 输出日志于druid-sql.log
[2018-02-07 14:15:50] DEBUG 134 statementLog - {conn-10001, pstmt-20000} created. INSERT INTO city ( id,name,state ) VALUES( ?,?,? )
[2018-02-07 14:15:50] DEBUG 134 statementLog - {conn-10001, pstmt-20000} Parameters : [null, b2ffa7bd-6b53-4392-aa39-fdf8e172ddf9, a9eb5f01-f6e6-414a-bde3-865f72097550]
[2018-02-07 14:15:50] DEBUG 134 statementLog - {conn-10001, pstmt-20000} Types : [OTHER, VARCHAR, VARCHAR]
[2018-02-07 14:15:50] DEBUG 134 statementLog - {conn-10001, pstmt-20000} executed. 5.113815 millis. INSERT INTO city ( id,name,state ) VALUES( ?,?,? )
[2018-02-07 14:15:50] DEBUG 134 statementLog - {conn-10001, stmt-20001} executed. 0.874903 millis. SELECT LAST_INSERT_ID()
[2018-02-07 14:15:52] DEBUG 134 statementLog - {conn-10001, stmt-20002, rs-50001} query executed. 0.622665 millis. SELECT 1