springboot配置日志输出

springboot默认使用的日志是logback，这就意味着我们不需要引入任何jar包

如果不做任何配置的话，默认的日志只是输出到控制台，这对于生产环境排查问题并不方便。

因此，我们需要对日志的输出做更进一步的配置

一、编写logback-spring.xml文件

这个文件呢，没啥好说的，就是将日志输出分成了两条流：控制台和文件

其中文件又对不同级别的日志info、warn、error分别输出到不同的文件

其中还定义了日志文件的最大大小和保留日期

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




<configuration>
    <property name="logDir" value="logs" />
    <property name="maxHistory" value="30" />

    <appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
        <encoder>
            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%npattern>
        encoder>
    appender>



    
    <appender name="ERROR"
              class="ch.qos.logback.core.rolling.RollingFileAppender">
        <file>${logDir}\error.logfile>
        <filter class="ch.qos.logback.classic.filter.LevelFilter">
            <level>ERRORlevel>
            <onMatch>ACCEPTonMatch>
            <onMismatch>DENYonMismatch>
        filter>
        <rollingPolicy
                class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <fileNamePattern>${logDir}\%d{yyyyMMdd}\error.%i.logfileNamePattern>
            <timeBasedFileNamingAndTriggeringPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
                <maxFileSize>100MBmaxFileSize>
            timeBasedFileNamingAndTriggeringPolicy>
            <maxHistory>${maxHistory}maxHistory>
        rollingPolicy>
        <encoder>
            <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger -
                %msg%npattern>
            <charset class="java.nio.charset.Charset">UTF-8charset>
        encoder>
        <append>falseappend>
        <prudent>falseprudent>
    appender>

    
    <appender name="WARN"
              class="ch.qos.logback.core.rolling.RollingFileAppender">
        <file>${logDir}\warn.logfile>
        <filter class="ch.qos.logback.classic.filter.LevelFilter">
            <level>WARNlevel>
            <onMatch>ACCEPTonMatch>
            <onMismatch>DENYonMismatch>
        filter>
        <rollingPolicy
                class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <fileNamePattern>${logDir}\%d{yyyyMMdd}\warn.%i.logfileNamePattern>
            <timeBasedFileNamingAndTriggeringPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
                <maxFileSize>100MBmaxFileSize>
            timeBasedFileNamingAndTriggeringPolicy>
            <maxHistory>${maxHistory}maxHistory>
        rollingPolicy>
        <encoder>
            <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger-%msg%npattern>
            <charset class="java.nio.charset.Charset">UTF-8charset>
        encoder>
        <append>falseappend>
        <prudent>falseprudent>
    appender>

    
    <appender name="INFO"
              class="ch.qos.logback.core.rolling.RollingFileAppender">
        <file>${logDir}\info.logfile>
        <filter class="ch.qos.logback.classic.filter.LevelFilter">
            <level>INFOlevel>
            <onMatch>ACCEPTonMatch>
            <onMismatch>DENYonMismatch>
        filter>
        <rollingPolicy
                class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <fileNamePattern>${logDir}\%d{yyyyMMdd}\info.%i.logfileNamePattern>
            <timeBasedFileNamingAndTriggeringPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
                <maxFileSize>100MBmaxFileSize>
            timeBasedFileNamingAndTriggeringPolicy>
            <maxHistory>${maxHistory}maxHistory>
        rollingPolicy>
        <encoder>
            <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger-%msg%npattern>
            <charset class="java.nio.charset.Charset">UTF-8charset>
        encoder>
        <append>falseappend>
        <prudent>falseprudent>
    appender>

    <root level="INFO">
        <appender-ref ref="CONSOLE" />
        <appender-ref ref="ERROR" />
        <appender-ref ref="WARN" />
        <appender-ref ref="INFO" />
    root>
configuration>

二、application.properties

#这个好像加不加都可以
logging.config=classpath:logback-spring.xml

大功告成，希望能帮到大家！

参考：

https://www.jianshu.com/p/2e6f7f9db93b