Java/SpringBoot + Maven 使用Logback

1.添加依赖

如果是普通Java + Maven项目，需要手动添加如下依赖

    <properties>
        <logback.version>1.2.3</logback.version>
        <slf4j.version>1.7.30</slf4j.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>${slf4j.version}</version>
        </dependency>
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-core</artifactId>
            <version>${logback.version}</version>
        </dependency>
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-access</artifactId>
            <version>${logback.version}</version>
        </dependency>
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <version>${logback.version}</version>
        </dependency>
    </dependencies>

如果是Spring Boot + Maven 项目

可以省略这一步，因为Spring-boot-starter已经包含了这些依赖

2. 在 src/main/resources（source folder）目录下新建logback.xml 配置文件如下:

配置方式1：所有级别的日志都在同一个文件中

可按需修改property的PROJECT_NAME，生成的log文件格式是 projectname.yyyy-MM-dd.i.log，同一天内每10M一个log文件

<?xml version="1.0" encoding="UTF-8"?>
<configuration scan="true" scanPeriod="10 seconds">


    <property name="LOG_HOME" value="./logs" />

    <property name="PROJECT_NAME" value="projectname" />

    <property name="LOG_PATTERN" value="%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} - %msg%n" />

    <!--输出到控制台 -->
    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
        <filter class="ch.qos.logback.classic.filter.ThresholdFilter">
            <level>info</level>
        </filter>
        <encoder>
            <pattern>${LOG_PATTERN}</pattern>
            <charset>UTF-8</charset>
        </encoder>
    </appender>


    <!--输出到文件 -->
    <appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">
            <FileNamePattern>${LOG_HOME}/${PROJECT_NAME}.%d{yyyy-MM-dd}.%i.log</FileNamePattern>
            <MaxHistory>30</MaxHistory>
            <MaxFileSize>10MB</MaxFileSize>
        </rollingPolicy>
        <encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
            <pattern>${LOG_PATTERN}</pattern>
            <charset>UTF-8</charset>
        </encoder>
    </appender>

    <!-- 设置 log 级别 info -->
    <root level="info">
        <appender-ref ref="STDOUT" />
        <appender-ref ref="FILE" />
    </root>



</configuration>

配置方式2：不同级别的log分开存在不同的文件中

可按需修改property的PROJECT_NAME，生成的log文件格式是 projectname.loglever.yyyy-MM-dd.i.log，同一天内每10M一个log文件

<!-- scan 当此属性设置为true时，配置文件如果发生改变，将会被重新加载，默认值为true。 -->
<!-- scanPeriod 设置监测配置文件是否有修改的时间间隔，如果没有给出时间单位，默认单位是毫秒。当scan为true时，此属性生效。默认的时间间隔为1分钟。 -->
<!-- debug 当此属性设置为true时，将打印出logback内部日志信息，实时查看logback运行状态。默认值为false。 -->
<configuration scan="true" scanPeriod="60 seconds" debug="false">

    <!-- 定义日志文件 输出位置 -->
    <property name="LOG_HOME" value="./logs" />
    
    <property name="PROJECT_NAME" value="projectname" />

    <!-- 日志最大的历史 30天 -->
    <property name="maxHistory" value="30" />

    <!-- 日志单文件最大 10MB -->
    <property name="maxSize" value="10MB" />

    <!-- 设置日志输出格式 -->
    <property name="LOG_PATTERN" value="%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} - %msg%n" />


    <!-- ConsoleAppender 控制台输出日志 -->
    <appender name="console" class="ch.qos.logback.core.ConsoleAppender">
        <encoder>
            <pattern>${LOG_PATTERN}</pattern>
            <charset>UTF-8</charset>
        </encoder>
    </appender>

    <!-- ERROR级别日志 -->
    <appender name="ERROR" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <!-- 过滤器，只记录WARN级别的日志 -->
        <filter class="ch.qos.logback.classic.filter.LevelFilter">
            <level>ERROR</level>
            <onMatch>ACCEPT</onMatch>
            <onMismatch>DENY</onMismatch>
        </filter>
        <!-- 滚动策略，它根据时间和日志文件大小来制定滚动策略. -->
        <rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">
            <FileNamePattern>${LOG_HOME}/${PROJECT_NAME}.error.%d{yyyy-MM-dd}.%i.log</FileNamePattern>
            <MaxHistory>${maxHistory}</MaxHistory>
            <MaxFileSize>${maxSize}</MaxFileSize>
        </rollingPolicy>
        <!-- 设置日志输出格式 -->
        <encoder>
            <pattern>${LOG_PATTERN}</pattern>
            <charset>UTF-8</charset>
        </encoder>
    </appender>

    <!-- WARN级别日志 appender -->
    <appender name="WARN" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <filter class="ch.qos.logback.classic.filter.LevelFilter">
            <level>WARN</level>
            <onMatch>ACCEPT</onMatch>
            <onMismatch>DENY</onMismatch>
        </filter>
        <rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">
            <FileNamePattern>${LOG_HOME}/${PROJECT_NAME}.warn.%d{yyyy-MM-dd}.%i.log</FileNamePattern>
            <MaxHistory>${maxHistory}</MaxHistory>
            <MaxFileSize>${maxSize}</MaxFileSize>
        </rollingPolicy>
        <encoder>
            <pattern>${LOG_PATTERN}</pattern>
            <charset>UTF-8</charset>
        </encoder>
    </appender>

    <!-- INFO级别日志 appender -->
    <appender name="INFO" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <filter class="ch.qos.logback.classic.filter.LevelFilter">
            <level>INFO</level>
            <onMatch>ACCEPT</onMatch>
            <onMismatch>DENY</onMismatch>
        </filter>
        <rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">
            <FileNamePattern>${LOG_HOME}/${PROJECT_NAME}.info.%d{yyyy-MM-dd}.%i.log</FileNamePattern>
            <MaxHistory>${maxHistory}</MaxHistory>
            <MaxFileSize>${maxSize}</MaxFileSize>
        </rollingPolicy>
        <encoder>
            <pattern>${LOG_PATTERN}</pattern>
            <charset>UTF-8</charset>
        </encoder>
    </appender>

    <!-- DEBUG级别日志 appender -->
    <appender name="DEBUG" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <filter class="ch.qos.logback.classic.filter.LevelFilter">
            <level>DEBUG</level>
            <onMatch>ACCEPT</onMatch>
            <onMismatch>DENY</onMismatch>
        </filter>
        <rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">
            <FileNamePattern>${LOG_HOME}/${PROJECT_NAME}.debug.%d{yyyy-MM-dd}.%i.log</FileNamePattern>
            <MaxHistory>${maxHistory}</MaxHistory>
            <MaxFileSize>${maxSize}</MaxFileSize>
        </rollingPolicy>
        <encoder>
            <pattern>${LOG_PATTERN}</pattern>
            <charset>UTF-8</charset>
        </encoder>
    </appender>

    <!-- TRACE级别日志 appender -->
    <appender name="TRACE" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <filter class="ch.qos.logback.classic.filter.LevelFilter">
            <level>TRACE</level>
            <onMatch>ACCEPT</onMatch>
            <onMismatch>DENY</onMismatch>
        </filter>
        <rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">
            <FileNamePattern>${LOG_HOME}/${PROJECT_NAME}.trace.%d{yyyy-MM-dd}.%i.log</FileNamePattern>
            <MaxHistory>${maxHistory}</MaxHistory>
            <MaxFileSize>${maxSize}</MaxFileSize>
        </rollingPolicy>
        <encoder>
            <pattern>${LOG_PATTERN}</pattern>
            <charset>UTF-8</charset>
        </encoder>
    </appender>

    <!-- root级别 DEBUG -->
    <root>
        <!-- 打印debug级别日志及以上级别日志 -->
        <level value="debug" />
        <!-- 控制台输出 -->
        <appender-ref ref="console" />
        <!-- 文件输出 -->
        <appender-ref ref="ERROR" />
        <appender-ref ref="INFO" />
        <appender-ref ref="WARN" />
        <appender-ref ref="DEBUG" />
        <appender-ref ref="TRACE" />
    </root>
</configuration>

3.使用

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class LogBack {
    private static Logger logger = LoggerFactory.getLogger(LogBack.class);

    public static void main(String[] args) {
        logger.error("============error====5555");
        logger.warn("============warn====5555");
        logger.info("==========info====5555");
        logger.debug("==========debug====5555");
        logger.trace("==========trace====5555");
    }

}

4. export jar 包时，也会把logback.xml打包

执行java -jar demolog.jar 后logs文件夹和jar包同级目录

参考

maven配置logback

注意：

rollingPolicy =TimeBasedRollingPolicy 是基于时间的，不能和 triggeringPolicy =SizeBasedTriggeringPolicy 一起组合使用，会有冲突

参考记一次logback无法按日生成日志文件

Java/SpringBoot + Maven 使用Logback

推荐阅读