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Slf4j + Logback 日志框架

Steven大约 2 分钟java

目前（2024 年 5 月 2 日）主流日志框架之一。

例子：Slf4j 适配 Logback

依赖

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.example</groupId>
        <artifactId>demo-java-log</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>

    <artifactId>demo-usage-slf4j-logback</artifactId>

    <dependencies>
<!--        <dependency>-->
<!--            <groupId>org.slf4j</groupId>-->
<!--            <artifactId>slf4j-api</artifactId>-->
<!--        </dependency>-->
<!--        <dependency>-->
<!--            <groupId>ch.qos.logback</groupId>-->
<!--            <artifactId>logback-core</artifactId>-->
<!--        </dependency>-->
        <!-- 默认依赖 slf4j-api 和 logback-core -->
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
        </dependency>
    </dependencies>
</project>

配置文件

<?xml version="1.0" encoding="UTF-8" ?>
<configuration scan="false">
    <property name="LOG_HOME" value="target/log-demo/logback/" />
    <property name="appName" value="spider" />

    <appender name="stdout" class="ch.qos.logback.core.ConsoleAppender">
        <layout class="ch.qos.logback.classic.PatternLayout">
            <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} %line: %msg %n</pattern>
        </layout>
    </appender>

    <appender name="appLogAppender" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <file>${LOG_HOME}/${appName}.log</file>
        <rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">
            <fileNamePattern>${LOG_HOME}/${appName}-%d{yyyy-MM-dd}-%i.log</fileNamePattern>
            <maxHistory>8</maxHistory>
            <maxFileSize>100MB</maxFileSize>
            <totalSizeCap>1GB</totalSizeCap>
        </rollingPolicy>
        <encoder>
            <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} %line: %msg %n</pattern>
            <charset>UTF-8</charset>
        </encoder>
    </appender>

    <!-- additivity="false" 表示父类日志器不重复输出 -->
    <logger name="org.example" level="debug" additivity="false">
        <appender-ref ref="stdout" />
        <appender-ref ref="appLogAppender" />
    </logger>

    <root level="info">
        <appender-ref ref="stdout" />
    </root>
</configuration>

相关信息

logback 不像 log4j 那样必须要有配置文件，它配置了默认的输出方式。

使用例子

测试代码
package org.example;

import org.junit.jupiter.api.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class InitTest {
    private static final Logger logger = LoggerFactory.getLogger(InitTest.class);
    @Test
    void testInit() {
        logger.trace("trace");
        logger.debug("debug");
        logger.info("info");
        logger.warn("warn");
        logger.error("error");
    }
}

异步日志

<appender class="ch.qos.logback.classic.AsyncAppender" >
    <appender-ref ref="stdout" />
</appender>

例子：Slf4j 桥接 Log4j 到 Logback

统一日志输出框架、日志输出格式

首先按上面步骤配置好 logback

依赖引入
<dependency>
    <groupId>ch.qos.logback</groupId>
    <artifactId>logback-classic</artifactId>
</dependency>

然后引入桥接依赖

<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>log4j-over-slf4j</artifactId>
</dependency>

然后排除三方件中的原日志框架依赖（或者将桥接依赖放在三方依赖前 - maven 优先级）

<!-- 三方件 -->
<dependency>
    <groupId>org.example</groupId>
    <artifactId>demo-usage-log4j-basic</artifactId>
    <version>1.0-SNAPSHOT</version>
    <exclusions>
        <exclusion>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
        </exclusion>
    </exclusions>
</dependency>

使用例子

测试代码
package org.example;

import org.junit.jupiter.api.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class InitTest {
    private static final Logger logger = LoggerFactory.getLogger(InitTest.class);
    @Test
    void testInit() {
        logger.trace("trace");
        logger.debug("debug");
        logger.info("info");
        logger.warn("warn");
        logger.error("error");
    }
}
Copyright © 2024 Steven