spring boot初探（二）——springboot配置log4j

spring-boot-starter中默认依赖了spring-boot-starter-logging而他实现的日志组件是Lockback。
事实上官方文档已经讲的非常清楚了，并且提供了两种日志实现的配置Logback和Log4j。具体的官方地址请看:http://docs.spring.io/spring-boot/docs/current/reference/html/howto-logging.html

我们这里主要讲一下如何配置log4j
1、根据官方的方法要想使用log4j，首先得讲默认的log依赖给去除，然后再引入log4j的jar包，pom文件如下:

<dependency>    <groupId>org.springframework.boot</groupId>    <artifactId>spring-boot-starter-web</artifactId></dependency><!-- exclude默认logging依赖 --><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><!-- 添加log4j2的依赖 --><dependency>    <groupId>org.springframework.boot</groupId>    <artifactId>spring-boot-starter-log4j2</artifactId></dependency>

注意：如果你想以yml或者json的方式编写配置文件的话（例如：log4j2.yml或者log4j2.json)官方给出了相应的依赖关系

Format Dependencies File names YAML com.fasterxml.jackson.core:jackson-databind
com.fasterxml.jackson.dataformat:jackson-dataformat-yaml log4j2.yaml
log4j2.yml JSON com.fasterxml.jackson.core:jackson-databind log4j2.json
log4j2.jsn

所以如果我们想和application.yml配置 文件保持一致的格式的话还需要添加两个依赖:

<dependency>    <groupId>com.fasterxml.jackson.core</groupId>      <artifactId>jackson-databind</artifactId>  </dependency>  <dependency>    <groupId>com.fasterxml.jackson.dataformat</groupId>      <artifactId>jackson-dataformat-yaml</artifactId>  </dependency>  

添加如上所示的依赖后我们就可以用log4j2.yml去配置了，接下来就直接贴配置详情了

Configuration:    status: warn    Properties: # 定义变量      Property:               - name: log.path          value: d:\\tmp\\logs        - name: project.name          value: spring-boot-log    Appenders:      Console:  #输出到控制台        name: CONSOLE        target: SYSTEM_OUT        ThresholdFilter:          level: trace        onMatch: ACCEPT          onMismatch: DENY        PatternLayout:          pattern: "%d{yyyy-MM-dd HH:mm:ss,SSS}:%4p %t (%F:%L) - %m%n"      # 输出到文件，超过128MB归档    RollingFile:         - name: ROLLING_FILE          ignoreExceptions: false          fileName: ${log.path}/${project.name}.log          filePattern: "${log.path}/$${date:yyyy-MM}/${project.name}-%d{yyyy-MM-dd}-%i.log.gz"          PatternLayout:            pattern: "%d{yyyy-MM-dd HH:mm:ss,SSS}:%4p %t (%F:%L) - %m%n"          Policies:            SizeBasedTriggeringPolicy:              size: "128 MB"          DefaultRolloverStrategy:            max: 1000    Loggers:      Root:        level: info        AppenderRef:          - ref: CONSOLE          - ref: ROLLING_FILE      Logger: # 为com.xjj包配置特殊的Log级别，方便调试        - name: com.test.dao          additivity: false          level: debug          AppenderRef:            - ref: CONSOLE            - ref: ROLLING_FILE

到这基本上你的log4j2就配置好了。