Spring Boot与Log4j2集成之java.lang.IllegalStateException: Logback configuration error detected:

比眉伴天荒 2022-06-08 13:40 162阅读 0赞

引言： 一个问题的分析与解决过程是表与里的过程，是一个大胆猜测与小心求证的过程，spring boot与log4j2的集成过程中，我将描述一下分析这个问题的思路和过程。 我一直强调一点： 重要的不是解决问题的结论，而是解决问题的思路和方法，即使在解决完问题之后，依然需要回过头复盘，在问题分析过程中的走过的弯路。

# 1 项目情况介绍 #

Spring Boot 1.5.7 , JDK 1.8, Log4j2.7  
在这个项目中，希望集成Log4j2作为默认的日志系统输出器。  
Log4j2.xml的定义如下：

"><Configuration status="off">
        <Properties>
            <Property name="LOG_PATH">.</Property>
        </Properties>
        <Appenders>
            
            <Console name="Console" target="SYSTEM_OUT">
                <PatternLayout pattern="%d{HH:mm:ss.SSS} %-5level %logger{36}.%M@%L - %msg%n"/>
                
            </Console>
            
            <RollingRandomAccessFile name="RollingFile" fileName="./aifasion.log" filePattern="${LOG_PATH}/aifasion.log.%d{yyyy-MM-dd-HH}">
                <PatternLayout pattern="%date{yyyy-MM-dd HH:mm:ss.SSS} %-5level %logger{36}.%M@%L - %msg%n"/>
                <Policies>
                    <TimeBasedTriggeringPolicy/>
                </Policies>
                <DefaultRolloverStrategy max="30"/>
            </RollingRandomAccessFile>
       </Appenders>
    
        <Loggers>
            
            <Logger name="org.springframework" level="info"/>
    
            
            <Logger name="org.jd.test" level="debug" additivity="false">
                <AppenderRef ref="Console"/>
                <AppenderRef ref="RollingFile"/>
            </Logger>
    
            
            <Root level="info">
                <AppenderRef ref="Console"/>
                <AppenderRef ref="RollingFile"/>
            </Root >
        </Loggers>
    </Configuration>

application.properties的文件定义如下：

> server.port=8080  
> logging.config=classpath:log4j2.xml  
> debug=true

上述为核心的配置文件信息。  
在pom.xml中，针对spring-boot-web中对于logging的引用进行了排除，配置信息如下：

<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>

# 2 问题描述 #

基于Spring Boot的向导创建基础项目，集成Log4j2，在项目启动过程中，报出如下的错误信息：

> SLF4J: Class path contains multiple SLF4J bindings.  
> SLF4J: Found binding in \[jar:file:/D:/DevSpace/M2Space/ch/qos/logback/logback-classic/1.1.11/logback-classic-1.1.11.jar!/org/slf4j/impl/StaticLoggerBinder.class\]  
> SLF4J: Found binding in \[jar:file:/D:/DevSpace/M2Space/org/apache/logging/log4j/log4j-slf4j-impl/2.7/log4j-slf4j-impl-2.7.jar!/org/slf4j/impl/StaticLoggerBinder.class\]  
> SLF4J: See [http://www.slf4j.org/codes.html\#multiple\_bindings][http_www.slf4j.org_codes.html_multiple_bindings] for an explanation.  
> SLF4J: Actual binding is of type \[ch.qos.logback.classic.util.ContextSelectorStaticBinder\]  
> The Class-Path manifest attribute in D:\\DevSpace\\M2Space\\org\\apache\\derby\\derby\\10.13.1.1\\derby-10.13.1.1.jar referenced one or more files that do not exist: D:\\DevSpace\\M2Space\\org\\apache\\derby\\derby\\10.13.1.1\\derbyLocale\_cs.jar,D:\\DevSpace\\M2Space\\org\\apache\\derby\\derby\\10.13.1.1\\derbyLocale\_de\_DE.jar,D:\\DevSpace\\M2Space\\org\\apache\\derby\\derby\\10.13.1.1\\derbyLocale\_es.jar,D:\\DevSpace\\M2Space\\org\\apache\\derby\\derby\\10.13.1.1\\derbyLocale\_fr.jar,D:\\DevSpace\\M2Space\\org\\apache\\derby\\derby\\10.13.1.1\\derbyLocale\_hu.jar,D:\\DevSpace\\M2Space\\org\\apache\\derby\\derby\\10.13.1.1\\derbyLocale\_it.jar,D:\\DevSpace\\M2Space\\org\\apache\\derby\\derby\\10.13.1.1\\derbyLocale\_ja\_JP.jar,D:\\DevSpace\\M2Space\\org\\apache\\derby\\derby\\10.13.1.1\\derbyLocale\_ko\_KR.jar,D:\\DevSpace\\M2Space\\org\\apache\\derby\\derby\\10.13.1.1\\derbyLocale\_pl.jar,D:\\DevSpace\\M2Space\\org\\apache\\derby\\derby\\10.13.1.1\\derbyLocale\_pt\_BR.jar,D:\\DevSpace\\M2Space\\org\\apache\\derby\\derby\\10.13.1.1\\derbyLocale\_ru.jar,D:\\DevSpace\\M2Space\\org\\apache\\derby\\derby\\10.13.1.1\\derbyLocale\_zh\_CN.jar,D:\\DevSpace\\M2Space\\org\\apache\\derby\\derby\\10.13.1.1\\derbyLocale\_zh\_TW.jar  
> 10:00:46.441 \[main\] DEBUG org.springframework.boot.devtools.settings.DevToolsSettings - Included patterns for restart : \[\]  
> 10:00:46.444 \[main\] DEBUG org.springframework.boot.devtools.settings.DevToolsSettings - Excluded patterns for restart : \[/spring-boot-starter/target/classes/, /spring-boot-autoconfigure/target/classes/, /spring-boot-starter-\[\\w-\]+/, /spring-boot/target/classes/, /spring-boot-actuator/target/classes/, /spring-boot-devtools/target/classes/\]  
> 10:00:46.444 \[main\] DEBUG org.springframework.boot.devtools.restart.ChangeableUrls - Matching URLs for reloading : \[file:/D:/workspace/testdemo/target/classes/\]  
> Logging system failed to initialize using configuration from ‘classpath:log4j2.xml’  
> java.lang.IllegalStateException: Logback configuration error detected:  
> ERROR in ch.qos.logback.core.joran.spi.Interpreter@3:17 - no applicable action for \[Properties\], current ElementPath is \[\[Configuration\]\[Properties\]\]  
> ERROR in ch.qos.logback.core.joran.spi.Interpreter@4:35 - no applicable action for \[Property\], current ElementPath is \[\[Configuration\]\[Properties\]\[Property\]\]  
> ERROR in ch.qos.logback.core.joran.spi.Interpreter@7:16 - no applicable action for \[Appenders\], current ElementPath is \[\[Configuration\]\[Appenders\]\]  
> ERROR in ch.qos.logback.core.joran.spi.Interpreter@9:53 - no applicable action for \[Console\], current ElementPath is \[\[Configuration\]\[Appenders\]\[Console\]\]  
> ERROR in ch.qos.logback.core.joran.spi.Interpreter@10:92 - no applicable action for \[PatternLayout\], current ElementPath is \[\[Configuration\]\[Appenders\]\[Console\]\[PatternLayout\]\]  
> ERROR in ch.qos.logback.core.joran.spi.Interpreter@16:91 - no applicable action for \[RollingRandomAccessFile\], current ElementPath is \[\[Configuration\]\[Appenders\]\[RollingRandomAccessFile\]\]  
> ERROR in ch.qos.logback.core.joran.spi.Interpreter@17:106 - no applicable action for \[PatternLayout\], current ElementPath is \[\[Configuration\]\[Appenders\]\[RollingRandomAccessFile\]\[PatternLayout\]\]  
> ERROR in ch.qos.logback.core.joran.spi.Interpreter@18:23 - no applicable action for \[Policies\], current ElementPath is \[\[Configuration\]\[Appenders\]\[RollingRandomAccessFile\]\[Policies\]\]  
> ERROR in ch.qos.logback.core.joran.spi.Interpreter@19:45 - no applicable action for \[TimeBasedTriggeringPolicy\], current ElementPath is \[\[Configuration\]\[Appenders\]\[RollingRandomAccessFile\]\[Policies\]\[TimeBasedTriggeringPolicy\]\]  
> ERROR in ch.qos.logback.core.joran.spi.Interpreter@21:48 - no applicable action for \[DefaultRolloverStrategy\], current ElementPath is \[\[Configuration\]\[Appenders\]\[RollingRandomAccessFile\]\[DefaultRolloverStrategy\]\]  
> ERROR in ch.qos.logback.core.joran.spi.Interpreter@25:14 - no applicable action for \[Loggers\], current ElementPath is \[\[Configuration\]\[Loggers\]\]  
> ERROR in ch.qos.logback.core.joran.spi.Interpreter@27:59 - no applicable action for \[Logger\], current ElementPath is \[\[Configuration\]\[Loggers\]\[Logger\]\]  
> ERROR in ch.qos.logback.core.joran.spi.Interpreter@30:69 - no applicable action for \[Logger\], current ElementPath is \[\[Configuration\]\[Loggers\]\[Logger\]\]  
> ERROR in ch.qos.logback.core.joran.spi.Interpreter@31:42 - no applicable action for \[AppenderRef\], current ElementPath is \[\[Configuration\]\[Loggers\]\[Logger\]\[AppenderRef\]\]  
> ERROR in ch.qos.logback.core.joran.spi.Interpreter@32:46 - no applicable action for \[AppenderRef\], current ElementPath is \[\[Configuration\]\[Loggers\]\[Logger\]\[AppenderRef\]\]  
> ERROR in ch.qos.logback.core.joran.spi.Interpreter@36:29 - no applicable action for \[Root\], current ElementPath is \[\[Configuration\]\[Loggers\]\[Root\]\]  
> ERROR in ch.qos.logback.core.joran.spi.Interpreter@37:41 - no applicable action for \[AppenderRef\], current ElementPath is \[\[Configuration\]\[Loggers\]\[Root\]\[AppenderRef\]\]  
> ERROR in ch.qos.logback.core.joran.spi.Interpreter@38:45 - no applicable action for \[AppenderRef\], current ElementPath is \[\[Configuration\]\[Loggers\]\[Root\]\[AppenderRef\]\]  
> at org.springframework.boot.logging.logback.LogbackLoggingSystem.loadConfiguration(LogbackLoggingSystem.java:162)  
> at org.springframework.boot.logging.AbstractLoggingSystem.initializeWithSpecificConfig(AbstractLoggingSystem.java:66)  
> at org.springframework.boot.logging.AbstractLoggingSystem.initialize(AbstractLoggingSystem.java:56)  
> at org.springframework.boot.logging.logback.LogbackLoggingSystem.initialize(LogbackLoggingSystem.java:115)  
> at org.springframework.boot.logging.LoggingApplicationListener.initializeSystem(LoggingApplicationListener.java:308)  
> at org.springframework.boot.logging.LoggingApplicationListener.initialize(LoggingApplicationListener.java:276)  
> at org.springframework.boot.logging.LoggingApplicationListener.onApplicationEnvironmentPreparedEvent(LoggingApplicationListener.java:239)  
> at org.springframework.boot.logging.LoggingApplicationListener.onApplicationEvent(LoggingApplicationListener.java:212)  
> at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172)  
> at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165)  
> at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139)  
> at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:122)  
> at org.springframework.boot.context.event.EventPublishingRunListener.environmentPrepared(EventPublishingRunListener.java:74)  
> at org.springframework.boot.SpringApplicationRunListeners.environmentPrepared(SpringApplicationRunListeners.java:54)  
> at org.springframework.boot.SpringApplication.prepareEnvironment(SpringApplication.java:325)  
> at org.springframework.boot.SpringApplication.run(SpringApplication.java:296)  
> at org.springframework.boot.SpringApplication.run(SpringApplication.java:1118)  
> at org.springframework.boot.SpringApplication.run(SpringApplication.java:1107)  
> at org.jd.test.TestdemoApplication.main(TestdemoApplication.java:14)  
> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)  
> at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)  
> at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)  
> at java.lang.reflect.Method.invoke(Unknown Source)  
> at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49)

以上是在系统启动过程中的错误信息，关键错误信息是：

> Logging system failed to initialize using configuration from ‘classpath:log4j2.xml’  
> java.lang.IllegalStateException: Logback configuration error detected:

# 3 问题分析过程 #

## 3.1 配置文件的格式或者定义错误 ##

根据刚才看到的错误信息，第一反应是log4j2.xml中定义的错误信息或者格式信息有误。  
根据这个判断，就直接在Log4j2的官方文档上，重新查阅了一番，结合定义中的内容格式，感觉格式都是完全正确的，没有什么出入问题。  
于是，我就使用排除法，将Log4j2.xml中的内容按照步骤，一部分一部分的进行验证排除，如果哪个部分中存在配置文件的配置错误，则可以定位出来。  
在一番定位之后，发现只要配置文件中存在内容，就会报出类似错误信息。  
结论是，应该不是配置文件的配置错误信息。

## 3.2 下载样例项目进行分析 ##

于是，从网上直接下来了spring-boot中自带的spring-boot-sample-actuator-log4j2项目，进行分析：  
发现其中pom.xml中的不同之处为：  
`<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter</artifactId> <exclusions> <exclusion> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-logging</artifactId> </exclusion> </exclusions> </dependency>`  
而之前的exclusion是在spring-boot-web-starter中排除的，就是这各位置的不同造成的。  
换个角度来分析，可以得出在spring-boot-web-starter中exclude掉的logging并未完全清楚干净，还有其他的类库或者包存在类似的以来。

# 4. 问题的解决 #

将spring-boot-starter-logging的包在spring-boot-starter中直接排除掉，从spring boot整体上进行替换，就可以解决这个问题：

<dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter</artifactId>
                <exclusions>
                    <exclusion>
                        <groupId>org.springframework.boot</groupId>
                        <artifactId>spring-boot-starter-logging</artifactId>
                    </exclusion>
                </exclusions>
            </dependency>

# 5 反思分析过程 #

在这个分析过程中，在看到日志的错误之时，第一反应就是配置文件的配置错误，这个方向从一开始就是错误的。  
在Pom.xml中虽然进行了exclude操作，但是并未真正的彻底排除掉logging；在看到样例程序之后，才感知到时logging的遗漏引用存在导致了问题。  
我又重新查看一遍项目中报出的异常日志，发现了一个我疏忽的细节问题：

在这个提示信息里面，明确了告知logging有多个绑定，logback、log4j2两种实现；目前使用的是logback的绑定，这个提示信息竟然忽略了…….

其实这个提示信息已经明确告知了问题出现的根源，只是当时被无意或者有意的忽略了…..

# 6 总结 #

经过这个问题的分析过程，我们可以得知，异常日志或者错误日志的分析是第一现场，非常的重要，它给了我们大量而丰富的第一手信息，为我们分析和解决问题提示了非常多的方向，需要进行慎重和小心的求证与验证。  
之后是exclude logging的依赖，虽然进行exclude排除操作，却并未完全进行替换掉，这个是在包的依赖中遗漏掉的。

[http_www.slf4j.org_codes.html_multiple_bindings]: http://www.slf4j.org/codes.html#multiple_bindings