在SpringBoot配置logging时，报：APP_NAME_IS_UNDEFINED问题。

yml配置如下：

logging:
  config: classpath:logback-spring.xml

logback-spring.xml配置文件：

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <contextName>{APP_NAME}</contextName>
    <!--重要的是这里-->
    <springProperty name="APP_NAME" scope="context" source="spring.application.name"/>
    <springProperty name="LOG_FILE" scope="context" source="logging.file" defaultValue="./logs/${APP_NAME}"/>
    <springProperty name="LOG_POINT_FILE" scope="context" source="logging.file" defaultValue="./logs/point"/>
    <springProperty name="LOG_MAXFILESIZE" scope="context" source="logback.filesize" defaultValue="50MB"/>
    <springProperty name="LOG_FILEMAXDAY" scope="context" source="logback.filemaxday" defaultValue="7"/>
    <springProperty name="ServerIP" scope="context" source="spring.cloud.client.ip-address" defaultValue="0.0.0.0"/>
    <springProperty name="ServerPort" scope="context" source="server.port" defaultValue="0000"/>

    <!-- 彩色日志 -->
    <!-- 彩色日志依赖的渲染类 -->
    <conversionRule conversionWord="clr" converterClass="org.springframework.boot.logging.logback.ColorConverter"/>
    <conversionRule conversionWord="wex"
                    converterClass="org.springframework.boot.logging.logback.WhitespaceThrowableProxyConverter"/>
    <conversionRule conversionWord="wEx"
                    converterClass="org.springframework.boot.logging.logback.ExtendedWhitespaceThrowableProxyConverter"/>

    <!-- 彩色日志格式 -->
    <property name="CONSOLE_LOG_PATTERN"
              value="[${APP_NAME}:${ServerIP}:${ServerPort}] [%clr(%X{traceid}){yellow},%clr(%X{X-B3-TraceId}){yellow}] %clr(%d{yyyy-MM-dd HH:mm:ss.SSS}){faint} %clr(%level){blue} %clr(${PID}){magenta} %clr([%thread]){orange} %clr(%logger){cyan} %m%n${LOG_EXCEPTION_CONVERSION_WORD:-%wEx}"/>
    <property name="CONSOLE_LOG_PATTERN_NO_COLOR"
              value="[${APP_NAME}:${ServerIP}:${ServerPort}] [%X{traceid},%X{X-B3-TraceId}] %d{yyyy-MM-dd HH:mm:ss.SSS} %level ${PID} [%thread] %logger %m%n${LOG_EXCEPTION_CONVERSION_WORD:-%wEx}"/>


    <!-- 控制台日志 -->
    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
        <withJansi>true</withJansi>
        <encoder>
            <pattern>${CONSOLE_LOG_PATTERN}</pattern>
            <charset>UTF-8</charset>
        </encoder>
    </appender>

    <!-- 按照每天生成常规日志文件 -->
    <appender name="ERROR" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <file>${LOG_FILE}/${APP_NAME}-error.log</file>
        <!-- 基于时间的分包策略 -->
        <rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">
            <fileNamePattern>${LOG_FILE}/${APP_NAME}-error.%d{yyyy-MM-dd}.%i.log</fileNamePattern>
            <maxFileSize>100MB</maxFileSize>
            <!--保留时间,单位:天-->
            <maxHistory>60</maxHistory>
        </rollingPolicy>
        <encoder>
            <pattern>${CONSOLE_LOG_PATTERN_NO_COLOR}</pattern>
            <charset>UTF-8</charset>
        </encoder>
        <triggeringPolicy class="ch.qos.logback.core.rolling.SizeBasedTriggeringPolicy">
            <MaxFileSize>100MB</MaxFileSize>
        </triggeringPolicy>
        <filter class="ch.qos.logback.classic.filter.LevelFilter"><!-- 只打印错误日志 -->
            <level>ERROR</level>
            <onMatch>ACCEPT</onMatch>
            <onMismatch>DENY</onMismatch>
        </filter>
    </appender>

    <!-- 按照每天生成常规日志文件 -->
    <appender name="INFO" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <file>${LOG_FILE}/${APP_NAME}-info.log</file>
        <!-- 基于时间的分包策略 -->
        <rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">
            <fileNamePattern>${LOG_FILE}/${APP_NAME}-info.%d{yyyy-MM-dd}.%i.log</fileNamePattern>
            <maxFileSize>100MB</maxFileSize>
            <!--保留时间,单位:天-->
            <maxHistory>60</maxHistory>
        </rollingPolicy>
        <encoder>
            <pattern>${CONSOLE_LOG_PATTERN_NO_COLOR}</pattern>
            <charset>UTF-8</charset>
        </encoder>
        <filter class="ch.qos.logback.classic.filter.LevelFilter">
            <level>INFO</level>
            <onMatch>ACCEPT</onMatch>
            <onMismatch>DENY</onMismatch>
        </filter>
    </appender>

    <root level="INFO">
        <appender-ref ref="STDOUT"/>
        <appender-ref ref="ERROR"/>
        <appender-ref ref="INFO"/>
    </root>

</configuration>

    <!--重要的是这一行-->
    <springProperty name="APP_NAME" scope="context" source="spring.application.name"/>

改为：

<springProperty name="APP_NAME" scope="context" source="spring.application.name" defaultValue="1111"/>

添加一个defaultValue属性，需要给一个默认值：defaultValue="你的日志名称"

原文件夹日志名称：

改后：