3-log4j2之输出日志到文件

一、添加maven依赖

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

二、log4j2.xml配置文件

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN">
    <properties>
        <Property name="console-pattern">%d{yyyy-MM-dd HH:mm:ss.SSS} [%t] [%level] %logger{36} - %msg%n</Property>
        <property name="error-file">log4j2learn.log</property>
    </properties>
    <Appenders>
        <Console name="Console" target="SYSTEM_OUT">
            <PatternLayout pattern="${console-pattern}" />
        </Console>

        <File name="FileAppender" fileName="${error-file}" >
            <PatternLayout pattern="${console-pattern}" />
        </File>

        <Async name="AsyncAppender">
            <AppenderRef ref="FileAppender"/>
        </Async>
    </Appenders>

    <Loggers>
        <Root level="info">
            <AppenderRef ref="Console" />
            <appenderRef ref="AsyncAppender" />
        </Root>
        <Logger name="AsyncFileLogger" level="error" additivity="false">
            <appenderRef ref="AsyncAppender" />
        </Logger>
    </Loggers>

</Configuration>

三、测试代码

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

/**
 * @author : zhangyanqing
 * @time : 2017/12/9
 * @desc : 输出日志到文件
 */
public class FileLoggerTest {
    public static final Logger LOGGER = LogManager.getLogger("AsyncFileLogger");
    public static void main(String[] args){
        LOGGER.trace("trace level");
        LOGGER.debug("debug level");
        LOGGER.info("info level");
        LOGGER.warn("warn level");
        LOGGER.error("error level");
        LOGGER.fatal("fatal level");
    }
}