SpringBoot 引入 Log4j2

一、引入依赖

SpringBoot默认使用logback的日志框架，所以需要排除logback，否则会有依赖冲突

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

<!-- log4j2 -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-log4j2</artifactId>
</dependency>
<!-- yml转xml -->
<dependency>
    <groupId>com.fasterxml.jackson.dataformat</groupId>
    <artifactId>jackson-dataformat-yaml</artifactId>
</dependency>

二、配置application.yml

logging:
  config: classpath:log4j2.yml

三、配置log4j2.yml

# 共有8个级别，按照从低到高为：ALL < TRACE < DEBUG < INFO < WARN < ERROR < FATAL < OFF。
# intLevel值依次为0,100,200,300,400,500,600,700
# intLevel 值越小，级别越高
Configuration:
  # 日志框架本身的输出日志级别
  status: WARN
  # 自动加载配置文件的间隔时间，不低于5秒
  monitorInterval: 5

  Properties: # 定义全局变量
    Property: 
      # 缺省配置（用于开发环境）。其他环境需要在VM参数中指定，如下：
      # 测试：-Dlog.level.console=warn -Dlog.level.xxx=trace
      # 生产：-Dlog.level.console=warn -Dlog.level.xxx=info
      - name: log.level.console
        value: info
      - name: log.path
        value: ./${project.name}_log
      - name: project.name
        value: your_project_name
      - name: log.pattern
        value: "%d{yyyy-MM-dd HH:mm:ss.SSS} -%5p ${PID:-} [%15.15t] %-30.30C{1.} : %m%n"

  Appenders:
    Console:  # 输出到控制台
      name: CONSOLE
      target: SYSTEM_OUT
      PatternLayout:   # 日志消息格式
        pattern: ${log.pattern}
    # 滚动日志
    RollingFile:
      - name: ROLLING_FILE
        fileName: ${log.path}/daily/${project.name}.log        # 输出文件的地址
        filePattern: "${log.path}/daily/$${date:yyyy-MM-dd}/${project.name}-%d{yyyy-MM-dd}-%i.log.gz"   # 文件生成规则
        PatternLayout:
          pattern: ${log.pattern}
        Filters:
          # 一定要先去除不接受的日志级别，然后获取需要接受的日志级别
          ThresholdFilter:   # 日志级别过滤器
            - level: error   # 日志级别
              onMatch: DENY  # 高于的拒绝
              onMismatch: NEUTRAL  # 低于的交给下一过滤器
            - level: info
              onMatch: ACCEPT
              onMismatch: DENY
        Policies:
          SizeBasedTriggeringPolicy: # 日志拆分规则
            size: "10MB"
          TimeBasedTriggeringPolicy:  # 按天分类
            modulate: true
            interval: 1
        DefaultRolloverStrategy:     # 单目录下，文件最多20个，超过会删除最早之前的
          max: 20
      # 错误日志
      - name: EXCEPTION_ROLLING_FILE
        ignoreExceptions: false
        fileName: ${log.path}/exception/${project.name}_exception.log
        filePattern: "${log.path}/exception/$${date:yyyy-MM-dd}/${project.name}-%d{yyyy-MM-dd}-%i.log.gz"
        ThresholdFilter:
          level: error
          # onMatch="ACCEPT" 匹配该级别及以上
          # onMatch="DENY"  不匹配该级别及以上
          # onMismatch="ACCEPT"  表示匹配该级别以下的级别
          # onMismatch="DENY"  不表示匹配该级别以下的级别
          onMatch: ACCEPT
          onMismatch: DENY
        PatternLayout:
          pattern: ${log.pattern}
        Policies:
          SizeBasedTriggeringPolicy: # 日志拆分规则
            size: "10MB"
          TimeBasedTriggeringPolicy:  # 按天分类
            modulate: true
            interval: 1
        DefaultRolloverStrategy:     # 文件最多100个
          max: 100
      # 警告日志
      - name: WARN_ROLLING_FILE
        ignoreExceptions: false
        fileName: ${log.path}/warn/${project.name}_warn.log
        filePattern: "${log.path}/warn/$${date:yyyy-MM-dd-dd}/${project.name}-%d{yyyy-MM-dd}-%i.log.gz"
        ThresholdFilter:
          level: warn
          # onMatch="ACCEPT" 匹配该级别及以上
          # onMatch="DENY"  不匹配该级别及以上
          # onMismatch="ACCEPT"  表示匹配该级别以下的级别
          # onMismatch="DENY"  不表示匹配该级别以下的级别
          onMatch: ACCEPT
          onMismatch: DENY
        PatternLayout:
          pattern: ${log.pattern}
        Policies:
          SizeBasedTriggeringPolicy: # 日志拆分规则
            size: "10MB"
          TimeBasedTriggeringPolicy:  # 按天分类
            modulate: true
            interval: 1
        DefaultRolloverStrategy:     # 文件最多100个
          max: 20
     # 用户行为日志
      - name: ROLLING_FILE_USER
        fileName: ${log.path}/user/user-${project.name}.log
        filePattern: "${log.path}/user/$${date:yyyy-MM-dd}/user-${project.name}-%d{yyyy-MM-dd}-%i.log.gz"
        PatternLayout:
          pattern: ${log.pattern}
        Filters:
          #        一定要先去除不接受的日志级别，然后获取需要接受的日志级别
          ThresholdFilter:
            - level: error
              onMatch: DENY
              onMismatch: NEUTRAL
            - level: info
              onMatch: ACCEPT
              onMismatch: DENY
        Policies:
          SizeBasedTriggeringPolicy: # 日志拆分规则
            size: "10MB"
          TimeBasedTriggeringPolicy:  # 按天分类
            modulate: true
            interval: 1
        DefaultRolloverStrategy:     # 文件最多100个
          max: 100

  Loggers:
    Root:
      # 共有8个级别，按照从低到高为：ALL < TRACE < DEBUG < INFO < WARN < ERROR < FATAL < OFF  选择all则输出全部的日志
      level: info
      AppenderRef:
        - ref: CONSOLE
        - ref: ROLLING_FILE
        - ref: EXCEPTION_ROLLING_FILE
        - ref: WARN_ROLLING_FILE
    Logger:
      - name: exception
        level: debug
        additivity: true  #追加
        AppenderRef:
          - ref: EXCEPTION_ROLLING_FILE

    #监听具体包下面的日志
    # Logger: 为com.example.aspect包配置特殊的Log级别，方便调试
      - name: com.example.aspect
        additivity: false
        level: info
        AppenderRef:
          - ref: CONSOLE
          - ref: ROLLING_FILE_USER

四、使用log4j2

@Slf4j
public class Log4j2TestController {
    public void test() {
        log.debug("debug");
        log.info("info");
        log.warn("warn");
        log.error("error");
    }
}