Springboot如何使用Logback实现日志配置

概述

默认情况下，SpringBoot内部使用logback作为系统日志实现的框架，将日志输出到控制台，不会写到日志文件。如果在application.properties或application.yml配置，这样只能配置简单的场景，保存路径、日志格式等。复杂的场景（区分 info 和 error 的日志、每天产生一个日志文件等）满足不了，只能自定义配置文件logback-spring.xml或者logback.xml。

logback配置详解

首先我们先了解下logback。

logback 主要分为三个模块：

• logback-core：是其他两个模块的基础模块

• logback-classic：是对 core 模块的扩展，相当于 log4j 的改良版。classic 模块实现了 Slf4j 的 API 因此可以便于和其他日志框架直接切换

• logback-access：与Servlet容器集成，以提供http访问日志功能。

logback配置

1.application .properties

# 日志打印信息配置
logging.config=classpath:logback-spring.xml

2.logback-spring.xml

    logback
    
    
        
        
            %d{HH:mm:ss.SSS} %contextName [%thread] %-5level %logger{36} - %msg%n
        
    
    
        
        ./logs/gf_scanning.log
        
        
            
            ./logs/gf_scanning.%d{yyyy-MM-dd}.%i.log
            
            30
            
                10MB
            
        
        
            %d{HH:mm:ss.SSS} %contextName [%thread] %-5level %logger{36} - %msg%n 
        
    
    
        
        
    

异常情况

遇到个奇怪的问题，按上述配置完成logback的配置后，大多项目可以正常运行并保存日志到文件，但有一个项目启动时报错。java.lang.IllegalStateException: Could not initialize Logback logging from classpath:logback-spring.xml ... Caused by: ch.qos.logback.core.joran.spi.JoranException: Parser configuration error occurred

Logging system failed to initialize using configuration from 'classpath:logback-spring.xml'
java.lang.IllegalStateException: Could not initialize Logback logging from classpath:logback-spring.xml
    at org.springframework.boot.logging.logback.LogbackLoggingSystem.loadConfiguration(LogbackLoggingSystem.java:168)
    at org.springframework.boot.logging.AbstractLoggingSystem.initializeWithSpecificConfig(AbstractLoggingSystem.java:66)
    at org.springframework.boot.logging.AbstractLoggingSystem.initialize(AbstractLoggingSystem.java:57)
    at org.springframework.boot.logging.logback.LogbackLoggingSystem.initialize(LogbackLoggingSystem.java:132)
    at org.springframework.boot.context.logging.LoggingApplicationListener.initializeSystem(LoggingApplicationListener.java:316)
    at org.springframework.boot.context.logging.LoggingApplicationListener.initialize(LoggingApplicationListener.java:282)
    at org.springframework.boot.context.logging.LoggingApplicationListener.onApplicationEnvironmentPreparedEvent(LoggingApplicationListener.java:240)
    at org.springframework.boot.context.logging.LoggingApplicationListener.onApplicationEvent(LoggingApplicationListener.java:216)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:176)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:169)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:143)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:131)
    at org.springframework.boot.context.event.EventPublishingRunListener.environmentPrepared(EventPublishingRunListener.java:85)
    at org.springframework.boot.SpringApplicationRunListeners.lambda$environmentPrepared$2(SpringApplicationRunListeners.java:66)
    at java.util.ArrayList.forEach(ArrayList.java:1257)
    at org.springframework.boot.SpringApplicationRunListeners.doWithListeners(SpringApplicationRunListeners.java:120)
    at org.springframework.boot.SpringApplicationRunListeners.doWithListeners(SpringApplicationRunListeners.java:114)
    at org.springframework.boot.SpringApplicationRunListeners.environmentPrepared(SpringApplicationRunListeners.java:65)
    at org.springframework.boot.SpringApplication.prepareEnvironment(SpringApplication.java:339)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:297)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1312)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1301)
    at cn.piesat.ScanningApplication.main(ScanningApplication.java:18)
Caused by: ch.qos.logback.core.joran.spi.JoranException: Parser configuration error occurred
    at ch.qos.logback.core.joran.event.SaxEventRecorder.buildSaxParser(SaxEventRecorder.java:89)
    at ch.qos.logback.core.joran.event.SaxEventRecorder.recordEvents(SaxEventRecorder.java:57)
    at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:151)
    at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:110)
    at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:53)
    at org.springframework.boot.logging.logback.LogbackLoggingSystem.configureByResourceUrl(LogbackLoggingSystem.java:188)
    at org.springframework.boot.logging.logback.LogbackLoggingSystem.loadConfiguration(LogbackLoggingSystem.java:165)
    ... 22 more
Caused by: org.xml.sax.SAXNotSupportedException: Feature: http://xml.org/sax/features/external-general-entities
    at org.apache.crimson.parser.XMLReaderImpl.setFeature(XMLReaderImpl.java:211)
    at org.apache.crimson.jaxp.SAXParserImpl.setFeatures(SAXParserImpl.java:143)
    at org.apache.crimson.jaxp.SAXParserImpl.(SAXParserImpl.java:126)
    at org.apache.crimson.jaxp.SAXParserFactoryImpl.newSAXParserImpl(SAXParserFactoryImpl.java:113)
    at org.apache.crimson.jaxp.SAXParserFactoryImpl.setFeature(SAXParserFactoryImpl.java:141)
    at ch.qos.logback.core.joran.event.SaxEventRecorder.buildSaxParser(SaxEventRecorder.java:82)
    ... 28 more
Disconnected from the target VM, address: '127.0.0.1:64222', transport: 'socket'

Process finished with exit code 1

可能是由于jar包冲突，在pom文件中单独引入logback-core的依赖后，问题解决。

    ch.qos.logback
    logback-core
    1.1.7


    ch.qos.logback
    logback-classic
    1.1.7
    
        
            ch.qos.logback
            logback-core