最近想尝试在通过Gradle配置Log4j,运行后并未有相关日志输出以及任何报错或警告。找了一圈感觉总少一个步骤，后续尝试配置出来了，感觉主要是配置以及相关java文件路径这块很多教程都未提及。

Gradle 配置添加依赖

dependencies {
    implementation 'org.apache.logging.log4j:log4j-api:2.19.0'  
    implementation 'org.apache.logging.log4j:log4j-core:2.19.0'
}

配置文件

• 路径参考

|--main
|  |--java
|     |--info.emperinter
|        |--main.java
|--resources
|  |--log4j2.xml

• log4j2.xml

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN">
    <Appenders>
        <Console name="console" target="SYSTEM_OUT">
            <PatternLayout pattern="%d{yyyy-MM-dd' 'HH:mm:ss.SSS} [%8t] [%-4level] %-36logger{36} - | %msg%n"/>
        </Console>
        <File name="all_logs_file" fileName="logs/all.log">
            <PatternLayout>
                <pattern>%d %p %c{1.} [%t] %m%n</pattern>
            </PatternLayout>
        </File>
        <File name="important_logs_file" fileName="logs/important.log">
            <Filters>
                <ThresholdFilter level="warn" onMatch="ACCEPT" onMismatch="DENY"/>
            </Filters>
            <PatternLayout>
                <pattern>%d %p %c{1.} [%t] %m%n</pattern>
            </PatternLayout>
        </File>
    </Appenders>
    <Loggers>
        <Root level="debug">
            <AppenderRef ref="console"/>
            <AppenderRef ref="all_logs_file"/>
            <AppenderRef ref="important_logs_file"/>
        </Root>
    </Loggers>
</Configuration>

使用

• main.java

package info.emperinter;  
import org.apache.logging.log4j.LogManager;  
import org.apache.logging.log4j.Logger;  

public class main {  
    static Logger logger = LogManager.getLogger(main.class.getName());  

    public static void main(String[] args) {  
        long start = System.currentTimeMillis();  
        logger.info("log4j start test");  
        logger.info("log4j end test");  
        long end = System.currentTimeMillis();  
        logger.info("main thread cost:" + (end - start) + "ms");  
    }  
}

参考

• https://logging.apache.org/log4j/2.x/