无法使用log4j2创建日志文件

Question

I am relatively new to log4j2. I am trying to create a log file using log4j2 but it is not getting created. Any help is appreciated. Thanks in advance.

log4j.xml Configuration File(below):

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE project>
<Configuration xmlns="http://logging.apache.org/log4j/2.0/config">
    <Properties>
        <Property name="basePath">../resources/logs</Property>
    </Properties>
    <Appenders>
        <!-- File Appender -->
        <File name="FILE" fileName="${basePath}/logfile.log" append="true">
            <PatternLayout
                pattern="[%-5p][%d{dd-MMM-yyyy HH:mm:ss a}] %C{0}.%M:(%L) - %m%n" />
        </File>
        <!-- Console Appender -->
        <Console name="STDOUT" target="SYSTEM_OUT">
            <PatternLayout
                pattern="[%-5p][%d{dd-MMM-yyyy HH:mm:ss a}] %C{0}.%M:(%L) - %m%n" />
        </Console>
    </Appenders>
    <Loggers>
        <Logger name="log" level="all" />
        <Root level="all">
            <AppenderRef ref="FILE" level="all" />
            <AppenderRef ref="STDOUT" level="all" />
        </Root>
    </Loggers>
</Configuration>

Project Folder Structure(below):

My Java Code(below):

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

public class Demo {

    public static Logger log;

    public static void main(String[] args) {
        System.err.println("Start");

        System.setProperty("log4j.configurationFile", "./resources/config/logger/log4j2.xml");
        log = LogManager.getLogger(Demo.class.getName());

        System.err.println("Initialisied Logger");
        log.trace("TRACE");
        log.debug("DEBUG");
        log.info("INFO");
        log.warn("WARN");
        log.error("ERROR");
        log.fatal("FATAL");

        System.err.println("END");
    }

}

Maven Dependency(below):

<dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-api</artifactId>
    <version>2.10.0</version>
</dependency>
<dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-core</artifactId>
    <version>2.10.0</version>
</dependency>

Console Outout(below):

Start
Initialisied Logger
[TRACE][28-Feb-2018 14:45:11 PM] Demo.main:(17) - TRACE
[DEBUG][28-Feb-2018 14:45:11 PM] Demo.main:(18) - DEBUG
[INFO ][28-Feb-2018 14:45:11 PM] Demo.main:(19) - INFO
[WARN ][28-Feb-2018 14:45:11 PM] Demo.main:(20) - WARN
[ERROR][28-Feb-2018 14:45:11 PM] Demo.main:(21) - ERROR
[FATAL][28-Feb-2018 14:45:11 PM] Demo.main:(22) - FATAL
END

Answer 1

Had similar issues. It would be easier to just show you a working code, I'll give you mine below ;)

pom.xml

<dependencies>
    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-api</artifactId>
        <version>2.10.0</version>
    </dependency>
    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-core</artifactId>
        <version>2.10.0</version>
    </dependency>
</dependencies>

    <resources>

        <resource>
            <directory>src/main/resources</directory>
            <targetPath>${project.build.directory}</targetPath>
            <includes>
                <include>log4j2.xml</include>
            </includes>
        </resource>

    </resources>

Demo.java

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

public class Demo {

    public static Logger log;

    public static void main(String[] args) {
        System.err.println("Start");

private static final Logger log = LogManager.getLogger(Demo.class);

        System.err.println("Initialisied Logger");
        log.trace("TRACE");
        log.debug("DEBUG");
        log.info("INFO");
        log.warn("WARN");
        log.error("ERROR");
        log.fatal("FATAL");

        System.err.println("END");
    }

}

It is better if you would copy your xml log file inside src/main/resources . log4j 2 - configuration issue

(i just took a random question about log4j2, because there are thousands, this would have helped you solved but i believe the code i posted here would help you too).

UPDATE: I forgot to paste a working log4j2.xml file.

<?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} [%t] %-5p %c{1}:%L - %msg%n" />


        <RollingFile name="RollingFile" filename="/var/log/mylog.log"
            filepattern="${logPath}/%d{YYYYMMddHHmmss}-fargo.log">
            <PatternLayout pattern="%d{YYYY-MM-dd HH:mm:ss} [%t] %-5p %c{1}:%L - %msg%n" />
            <Policies>
                <SizeBasedTriggeringPolicy size="10 MB" />
            </Policies>
            <DefaultRolloverStrategy max="20" />
        </RollingFile>

    </Appenders>
    <Loggers>
        <Root level="info">
            <AppenderRef ref="Console" />
            <AppenderRef ref="RollingFile" />
        </Root>
    </Loggers>
</Configuration>

UPDATE 2: And, since everybody love screenshots, you'd have this folder structure. Netbeans, Eclipse ... Names could change, but src/main/resources and pom.xml are the same across all IDE.

Answer 2

Solved it by replacing the two dots to one dot ie ../resources to ./resources I know it is a silly mistake. :-)

<Properties>
        <Property name="basePath">../resources/logs</Property>
</Properties>

Credit to @vikingsteve for pointing it out in the comments.