spring boot 加载日志框架后经常出现 LOG_PATH_IS_UNDEFINED 目录怎么办？

问题：

############################## 日志配置 ######################################
#日志只输出root及以上级别的信息
logging.level.root=debug
logging.config=classpath:logback-spring.xml
logging.path=D:/libdev/log/${spring.application.name}

　　logback-spring.xml

<?xml version="1.0" encoding="UTF-8"?>
<configuration scan="true" scanPeriod="60 seconds">
    <include resource="org/springframework/boot/logging/logback/base.xml"/>

    <springProperty scope="context" name="LOG_PATH" source="log.path"/>

    <appender name="INFO_FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <filter class="ch.qos.logback.classic.filter.ThresholdFilter">
            <level>INFO</level>
        </filter>
        <file>${LOG_PATH}/info.log</file>
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <fileNamePattern>${LOG_PATH}/info-%d{yyyyMMdd}.log.%i</fileNamePattern>
            <timeBasedFileNamingAndTriggeringPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
                <maxFileSize>500MB</maxFileSize>
            </timeBasedFileNamingAndTriggeringPolicy>
            <maxHistory>2</maxHistory>
        </rollingPolicy>
        <layout class="ch.qos.logback.classic.PatternLayout">
            <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{36} -%msg%n</pattern>
        </layout>
    </appender>

    <appender name="WARN_FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <filter class="ch.qos.logback.classic.filter.ThresholdFilter">
            <level>WARN</level>
        </filter>
        <file>${LOG_PATH}/warn.log</file>
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <fileNamePattern>${LOG_PATH}/warn-%d{yyyyMMdd}.log.%i</fileNamePattern>
            <timeBasedFileNamingAndTriggeringPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
                <maxFileSize>100MB</maxFileSize>
            </timeBasedFileNamingAndTriggeringPolicy>
            <maxHistory>2</maxHistory>
        </rollingPolicy>
        <layout class="ch.qos.logback.classic.PatternLayout">
            <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{36} -%msg%n</pattern>
        </layout>
    </appender>

    <appender name="ERROR_FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <filter class="ch.qos.logback.classic.filter.ThresholdFilter">
            <level>ERROR</level>
        </filter>
        <file>${LOG_PATH}/error.log</file>
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <fileNamePattern>${LOG_PATH}/error-%d{yyyyMMdd}.log.%i</fileNamePattern>
            <timeBasedFileNamingAndTriggeringPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
                <maxFileSize>100MB</maxFileSize>
            </timeBasedFileNamingAndTriggeringPolicy>
            <maxHistory>2</maxHistory>
        </rollingPolicy>
        <layout class="ch.qos.logback.classic.PatternLayout">
            <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{36} -%msg%n</pattern>
        </layout>
    </appender>

    <root level="INFO">
        <appender-ref ref="INFO_FILE" />
        <appender-ref ref="WARN_FILE" />
        <appender-ref ref="ERROR_FILE" />
    </root>

</configuration>