1、工程log4j 配置

 ### set log levels ###
log4j.rootLogger = debug,stdout,R


### 输出到控制台 ###
log4j.appender.stdout = org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target = System.out
log4j.appender.stdout.Threshold = INFO
log4j.appender.stdout.layout = org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss} %p [%t] %c{2} (%M:%L) - %m%n

### 输出etl-web日志到文件 ###
log4j.appender.R = org.apache.log4j.DailyRollingFileAppender
log4j.appender.R.ImmediateFlush=true
log4j.appender.R.Append = true
log4j.appender.R.File =logs/lucene.log
log4j.appender.R.encoding=UTF-8
log4j.appender.R.Threshold = INFO
log4j.appender.R.DatePattern='.'yyyy-MM-dd
log4j.appender.R.layout = org.apache.log4j.PatternLayout
log4j.appender.R.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss} %p [%t] %c{2} (%M:%L) - %m%n


pom.xml添加依赖:

    <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.7.2</version>
        </dependency>

代码中填写

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
 public static final Logger LOG= LoggerFactory.getLogger(QueryIndexInfoByLuceneFileDir.class);
原文地址:https://www.cnblogs.com/yangh2016/p/5888139.html