SpringBoot系列(12)：SpringBoot集成log4j2日志配置

最近项目上有使用到log4j2日志模板配置，本文简单总结一下之前的学习笔记，如有纰漏之处，请批评指正。

1. log4j2日志依赖

使用log4j2日志模板时，需要引入相关依赖，下边的两种依赖方式均可。

1.1 使用sl4j依赖时

    <properties>
        <spring-boot.version>2.6.13spring-boot.version>
        <log4j2.version>2.18.0log4j2.version>
    properties>
 
    <dependencies>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
            <version>${spring-boot.version}version>
        dependency>
 
        
        <dependency>
            <groupId>org.slf4jgroupId>
            <artifactId>slf4j-apiartifactId>
            <version>1.7.30version>
        dependency>
        <dependency>
            <groupId>org.apache.logging.log4jgroupId>
            <artifactId>log4j-coreartifactId>
            <version>${log4j2.version}version>
        dependency>
        <dependency>
            <groupId>org.apache.logging.log4jgroupId>
            <artifactId>log4j-apiartifactId>
            <version>${log4j2.version}version>
        dependency>
        <dependency>
            <groupId>org.apache.logging.log4jgroupId>
            <artifactId>log4j-slf4j-implartifactId>
            <version>${log4j2.version}version>
            <exclusions>
                <exclusion>
                    <groupId>org.slf4jgroupId>
                    <artifactId>slf4j-apiartifactId>
                exclusion>
            exclusions>
        dependency>
 
 

• 使用sl4j依赖时，需要在打印日志的类中声明一个日志对象处理

private static  final Logger LOGGER = LoggerFactory.getLogger(xxxxxx.class);
 
// 方法内
LOGGER .info("application started");

 这种方式需要配置很多次，略繁琐。可以类上使用注解@sl4j来代替

1.2 使用lombok依赖时

如果不想像上边那样写一堆sl4f依赖，可以直接使用lombok依赖，作用是相同的。仅仅在需要打印日志的类上配置上注解@sl4j即可。

        <dependency>
            <groupId>org.projectlombokgroupId>
            <artifactId>lombokartifactId>
            <version>1.18.24version>
        dependency>

• 在需要打印日志的方法内直接使用

// 方法内
log.info("application started");

 1.3 小结

上边两种配置方式，原理雷同，看实际项目需要和个人喜好使用即可。

2. log4j2.xml日志模板配置

"1.0" encoding="UTF-8"?>
<configuration status="OFF">
 
    <properties>
        
        <property name="LOG_LEVEL">INFOproperty>
        
        <property name="APP_NAME" value="spring-mvc-log"/>
        
        <property name="LOG_HOME">./logsproperty>
        
        <property name="LOG_MAX_HISTORY" value="10d"/>
        
        <property name="LOG_MAX_FILE_SIZE" value="10 MB"/>
        
        <property name="LOG_TOTAL_NUMBER_DAILY" value="10"/>
        
        <property name="ARCHIVE_FILE_SUFFIX" value="zip"/>
        
        <property name="LOG_FILE_NAME" value="${LOG_HOME}/${APP_NAME}"/>
        <property name="FILE_NAME_PATTERN" value="${LOG_HOME}/${APP_NAME}.%d{yyyy-MM-dd}"/>
 
        
        
        <property name="ENCODER_PATTERN_CONSOLE">%blue{%d{yyyy-MM-dd HH:mm:ss.SSS}} | %highlight{%-5level}{ERROR=Bright RED, WARN=Bright Yellow, INFO=Bright Green, DEBUG=Bright Cyan, TRACE=Bright White} | %yellow{%t} | %cyan{%l} >>>>> %white{%msg%n}property>
        
        <property name="ENCODER_PATTERN">%d{yyyy-MM-dd HH:mm:ss.SSS} | %-5level | %t | %c{1.} >>>>> %msg%nproperty>
    properties>
 
    <Appenders>
        
        <Console name="Console" target="SYSTEM_OUT">
            
            <PatternLayout pattern="${ENCODER_PATTERN_CONSOLE}" />
        Console>
        
        <RollingFile name="RollingFileAll" fileName="${LOG_FILE_NAME}.ALL.log" filePattern="${FILE_NAME_PATTERN}.ALL.%i.log.${ARCHIVE_FILE_SUFFIX}">
            
            <ThresholdFilter level="${LOG_LEVEL}" onMatch="ACCEPT" onMismatch="DENY" />
            
            <PatternLayout pattern="${ENCODER_PATTERN}" />
            <Policies>
                
                <TimeBasedTriggeringPolicy />
                
                <SizeBasedTriggeringPolicy size="${LOG_MAX_FILE_SIZE}" />
            Policies>
            
            <DefaultRolloverStrategy compressionLevel="9" max="${LOG_TOTAL_NUMBER_DAILY}">
                <Delete basePath="${LOG_HOME}" maxDepth="1">
                    <IfFileName glob="${APP_NAME}.*.ALL.*.log.${ARCHIVE_FILE_SUFFIX}" />
                    <IfLastModified age="${LOG_MAX_HISTORY}" />
                Delete>
            DefaultRolloverStrategy>
        RollingFile>
 
        <RollingFile name="RollingFileDebug"
                     fileName="${LOG_FILE_NAME}.DEBUG.log"
                     filePattern="${FILE_NAME_PATTERN}.DEBUG.%i.log.${ARCHIVE_FILE_SUFFIX}">
            <Filters>
                <ThresholdFilter level="DEBUG" />
                <ThresholdFilter level="INFO" onMatch="DENY"
                                 onMismatch="NEUTRAL" />
            Filters>
            <PatternLayout pattern="${ENCODER_PATTERN}" />
            <Policies>
                
                <TimeBasedTriggeringPolicy />
                
                <SizeBasedTriggeringPolicy size="${LOG_MAX_FILE_SIZE}" />
            Policies>
            
            <DefaultRolloverStrategy compressionLevel="9"
                                     max="${LOG_TOTAL_NUMBER_DAILY}">
                <Delete basePath="${LOG_HOME}" maxDepth="1">
                    <IfFileName glob="${APP_NAME}.*.DEBUG.*.log.${ARCHIVE_FILE_SUFFIX}" />
                    <IfLastModified age="${LOG_MAX_HISTORY}" />
                Delete>
            DefaultRolloverStrategy>
        RollingFile>
 
        <RollingFile name="RollingFileWarn" fileName="${LOG_FILE_NAME}.WARN.log"
                     filePattern="${FILE_NAME_PATTERN}.WARN.%i.log.${ARCHIVE_FILE_SUFFIX}">
            <Filters>
                <ThresholdFilter level="WARN" />
                <ThresholdFilter level="ERROR" onMatch="DENY"
                                 onMismatch="NEUTRAL" />
            Filters>
            <PatternLayout pattern="${ENCODER_PATTERN}" />
            <Policies>
                
                <TimeBasedTriggeringPolicy />
                
                <SizeBasedTriggeringPolicy size="${LOG_MAX_FILE_SIZE}" />
            Policies>
            
            <DefaultRolloverStrategy compressionLevel="9"
                                     max="${LOG_TOTAL_NUMBER_DAILY}">
                <Delete basePath="${LOG_HOME}" maxDepth="1">
                    <IfFileName glob="${APP_NAME}.*.WARN.*.log.${ARCHIVE_FILE_SUFFIX}" />
                    <IfLastModified age="${LOG_MAX_HISTORY}" />
                Delete>
            DefaultRolloverStrategy>
        RollingFile>
 
        <RollingFile name="RollingFileError"
                     fileName="${LOG_FILE_NAME}.ERROR.log"
                     filePattern="${FILE_NAME_PATTERN}.ERROR.%i.log.${ARCHIVE_FILE_SUFFIX}">
            <Filters>
                <ThresholdFilter level="ERROR" />
            Filters>
            <PatternLayout pattern="${ENCODER_PATTERN}" />
            <Policies>
                <TimeBasedTriggeringPolicy />
                <SizeBasedTriggeringPolicy size="${LOG_MAX_FILE_SIZE}" />
            Policies>
            <DefaultRolloverStrategy compressionLevel="9"   max="${LOG_TOTAL_NUMBER_DAILY}">
                <Delete basePath="${LOG_HOME}" maxDepth="1">
                    <IfFileName glob="${APP_NAME}.*.ERROR.*.log.${ARCHIVE_FILE_SUFFIX}" />
                    <IfLastModified age="${LOG_MAX_HISTORY}" />
                Delete>
            DefaultRolloverStrategy>
        RollingFile>
    Appenders>
 
    
    <Loggers>
        <root level="${LOG_LEVEL}">
            <appender-ref ref="Console"/>
            <appender-ref ref="RollingFileAll"/>
            <appender-ref ref="RollingFileDebug"/>
            <appender-ref ref="RollingFileWarn"/>
            <appender-ref ref="RollingFileError"/>
        root>
    Loggers>
configuration>

3. 开启Console彩色打印

• 彩色打印配置

IDEA控制台没有打印彩色日志的主要原因在于 Log4j - 2.10 版本以后Log4j2默认关闭了Jansi（一个支持输出ANSI颜色的类库）

修改jvm参数: -Dlog4j.skipJansi=false

• 修改前边pom.xml，添加彩色打印依赖

<dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
            <version>${spring-boot.version}version>
            <exclusions>
                <exclusion>
                    <groupId>org.springframework.bootgroupId>
                    <artifactId>spring-boot-starter-loggingartifactId>
                exclusion>
            exclusions>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-log4j2artifactId>
            <version>${spring-boot.version}version>
        dependency>

4. application.yml中配置

logging:
  config: classpath:log4j2.xml
  level:
    com.hl.magic.mvc: debug

5.常见模板中日志格式配置

• springboot默认的日志格式

%d{yyyy-MM-dd HH:mm:ss.SSS} %5p ${PID:-} [%15.15t] %-40.40logger{39} : %m%n

• logback默认的日志格式

%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n

• lishuoboy推荐日志格式

%d{MM-dd HH:mm:ss.SSS} [%5level] %4line %40.40logger{39}.%-30.30method : %m%n