SpringBoot中使用日志

本篇记录如何使用SpringBoot的默认日志和其他日志

一、使用默认日志logback

方法1：通过配置application.properties（不推荐）

　　日志的默认级别是info，且默认只打印在控制台

　　测试如下，控制台只打印出 info、warn、error，不打印debug

package com.leiyuke.temp;

@SpringBootApplication
public class App {

    private static final Logger logger = LoggerFactory.getLogger(App.class);

    public static void main(String[] args) {
        ConfigurableApplicationContext context=SpringApplication.run(App.class, args);
        logger.debug("debug");
        logger.info("info");
        logger.warn("warn");
        logger.error("error");
        context.close();
    }
}

　　配置application.yml如下，控制台会打印出debug、info、warn、error

logging:
  file: d:/springboottemp/logs/mylog.log
  level:
    root: info
    com:
      leiyuke:
        temp: debug
  pattern:
    console: '%d{yyyy-MM-dd HH:mm:ss} %m%n'
    file: '%d{yyyy-MM-dd} %t %-4r %p %F[%L]: %m%n'

方法2：通过配置logback.xml（推荐）

　　新建文件resources/logback.xml，并删掉application.yml中关于日志的配置

<?xml version="1.0" encoding="UTF-8"?>
<configuration debug="true" scan="true" scanPeriod="60 seconds">
    <contextName>logback</contextName>
    <property name="logFilePath" value="D:/springboottemp/logs"/>
    <property name="logFileName" value="mylog"/>

    <appender name="stdout" class="ch.qos.logback.core.ConsoleAppender">
        <filter class="ch.qos.logback.classic.filter.ThresholdFilter">
            <level>debug</level>
        </filter>
        <encoder>
            <pattern>%d [%thread] %-5level %logger{36} [%file : %line] - %msg%n</pattern>
        </encoder>
    </appender>

    <appender name="file" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <file>${logFilePath}/${logFileName}.log</file>
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <fileNamePattern>${logFilePath}/${logFileName}.%d{yyyy-MM-dd.HH}.log.gz</fileNamePattern>
            <maxHistory>60</maxHistory>
            <totalSizeCap>20GB</totalSizeCap>
        </rollingPolicy>
        <triggeringPolicy class="ch.qos.logback.core.rolling.SizeBasedTriggeringPolicy">
            <maxFileSize>100MB</maxFileSize>
        </triggeringPolicy>
        <encoder>
            <pattern>%d [%thread] %-5level %logger{36} [%file : %line] - %msg%n</pattern>
        </encoder>
    </appender>

    <root level="debug">
        <appender-ref ref="stdout"/>
        <appender-ref ref="file"/>
    </root>

    <logger name="com.leiyuke.temp" level="debug"/>

</configuration>

　　关于logback的具体用法，参考我这篇文章logback介绍和配置详解

二、使用日志log4j2

　　1）首先排除掉默认的logback，然后引入log4j2的依赖

<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>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-log4j2</artifactId>
    <version>2.0.4.RELEASE</version>
</dependency>

　　2）在resources中新建log4j2.xml 去掉application.properties中logback日志的配置

<?xml version="1.0" encoding="UTF-8" ?>
<configuration>
    <appenders>
        <Console name="CONSOLE" target="system_out" follow="true">
            <PatternLayout pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} |-%-5level[%thread] %c [%L] -| %msg%n" />
        </Console>
    </appenders>
    <loggers>
        <root level="warn">
            <appenderref ref="CONSOLE" />
        </root>
    </loggers>
</configuration>

 　　执行一中的main方法，控制台只输出warn和error，配置生效