目前市面中使用的大多数是spring boot项目，下面我说的方案sring也适用。
在这里给你们推荐一套目前 最火的Java后端日志框架方案：
门户日志用：slf4j
日志实现用：log4j2java
具体的配置或者优化以下详情
一、导入依赖
log4j2应尽可能使用同一版本，不然可能出现不兼容的状况web
// log升级配置
compile('org.apache.logging.log4j:log4j-1.2-api:2.9.1')
compile('org.apache.logging.log4j:log4j-web:2.9.1')
compile('org.apache.logging.log4j:log4j-core:2.9.1')
compile('org.apache.logging.log4j:log4j-api:2.9.1')
// log
// compile('log4j:log4j:1.2.17')
compile('org.slf4j:slf4j-api:1.6.6')
compile('org.slf4j:slf4j-log4j12:1.7.21')
二、建立log4j2.properties
（若是有log4j.properties要删除的）
（下面还有一种使用log4j.xml的方法，两种任选其一，如今是倾向于用xml）spring
status = warn
name = MyApp
#指定输出源‘类型’为控制台
appender.console.type = Console
appender.console.name = consoleLogDemo
appender.console.filter.threshold.type = ThresholdFilter
appender.console.filter.threshold.level = debug
appender.console.layout.type = PatternLayout
appender.console.layout.pattern = [%-5p] [%d{yyyy-MM-dd HH:mm:ss}] [%C{1}:%M:%L] %m%n
appender.console.target = System_out
appender.rolling.type = RollingFile
appender.rolling.name = fileLogDemo
appender.rolling.filter.threshold.type = ThresholdFilter
appender.rolling.filter.threshold.level = info
appender.rolling.layout.type = PatternLayout
appender.rolling.layout.pattern = [%-5p] [%d{yyyy-MM-dd HH:mm:ss}] [%C{1}:%M:%L] %m%n
appender.rolling.append = true
appender.rolling.fileName =/data/logs/workflow/web.log
appender.rolling.filePattern=/data/logs/wokflow/web.log.%d{yyyy-MM-dd}
appender.rolling.policies.type = Policies
appender.rolling.policies.time.type = TimeBasedTriggeringPolicy
appender.rolling.policies.time.interval = 2
appender.rolling.policies.time.modulate = true
appender.rolling.policies.size.type = SizeBasedTriggeringPolicy
appender.rolling.policies.size.size=100MB
appender.rolling.strategy.type = DefaultRolloverStrategy
appender.rolling.strategy.max = 5
logger.rolling.name = com.XXX
logger.rolling.level = info
logger.rolling.additivity = false
logger.rolling.appenderRef.rolling.ref = fileLogDemo
#指明根级日志的级别
rootLogger.level = info
#指定哪些appender输出源是根级日志的输出级别
rootLogger.appenderRef.consolelogdemo.ref = consoleLogDemo
rootLogger.appenderRef.filelogdemo.ref = fileLogDemo
三、log4j2.xmlsql
<?xml version="1.0" encoding="UTF-8"?>
<!-- 日志级别按照从低到高为：ALL < TRACE < DEBUG < INFO < WARN < ERROR < FATAL < OFF -->
<!--status="WARN" :用于设置log4j2自身内部日志的信息输出级别，默认是OFF-->
<Configuration status="WARN" monitorInterval="30">
<!--自定义一些常量，以后使用${变量名}引用-->
<properties>
<property name="LOG_PATH">D:/logs</property>
<property name="PATTERN" value="%d{yyyy-MM-dd HH:mm:ss.SSS} [%t] [%l] %p - %m%n%n"/>
<property name="INFO_LOG">info</property>
<property name="DEBUG_LOG">debug</property>
<property name="ERROR_LOG">error</property>
</properties>
<!--appenders:定义输出内容,输出格式,输出方式,日志保存策略等,经常使用其下三种标签[console,File,RollingFile]-->
<Appenders>
<Console name="Console" target="SYSTEM_OUT">
<ThresholdFilter level="DEBUG" onMatch="ACCEPT" onMismatch="DENY"/>
<PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n" />
</Console>
<RollingFile name="DebugAppender" fileName="${LOG_PATH}/${DEBUG_LOG}.log"
filePattern="${LOG_PATH}/$${date:yyyy-MM}/debug-%d{yyyy-MM-dd}-%i.log"
immediateFlush="true">
<!--控制台只输出level及以上级别的信息（onMatch），其余的直接拒绝（onMismatch）-->
<Filters>
<ThresholdFilter level="INFO" onMatch="DENY" onMismatch="NEUTRAL"/>
<ThresholdFilter level="DEBUG" onMatch="ACCEPT" onMismatch="DENY"/>
</Filters>
<PatternLayout pattern="${PATTERN}" />
<Policies>
<TimeBasedTriggeringPolicy />
<SizeBasedTriggeringPolicy size="10 MB" />
</Policies>
<!-- DefaultRolloverStrategy属性如不设置，则默认为最多同一文件夹下7个文件，这里设置了20 -->
<DefaultRolloverStrategy max="20" />
</RollingFile>
<RollingFile name="InfoAppender" fileName="${LOG_PATH}/${INFO_LOG}.log"
filePattern="${LOG_PATH}/$${date:yyyy-MM}/info-%d{yyyy-MM-dd}-%i.log"
immediateFlush="true">
<!--控制台只输出level及以上级别的信息（onMatch），其余的直接拒绝（onMismatch）-->
<Filters>
<ThresholdFilter level="WARN" onMatch="DENY" onMismatch="NEUTRAL" />
<ThresholdFilter level="INFO" onMatch="ACCEPT" onMismatch="DENY"/>
</Filters>
<PatternLayout pattern="${PATTERN}" />
<Policies>
<TimeBasedTriggeringPolicy />
<!-- SizeBasedTriggeringPolicy :文件大小滚动策略-->
<SizeBasedTriggeringPolicy size="10 MB" />
</Policies>
<!-- DefaultRolloverStrategy属性如不设置，则默认为最多同一文件夹下7个文件，这里设置了20 -->
<DefaultRolloverStrategy max="20" />
</RollingFile>
<RollingFile name="ErrorAppender" fileName="${LOG_PATH}/${ERROR_LOG}.log"
filePattern="${LOG_PATH}/$${date:yyyy-MM}/error-%d{yyyy-MM-dd}-%i.log"
immediateFlush="true">
<!--控制台只输出level及以上级别的信息（onMatch），其余的直接拒绝（onMismatch）-->
<Filters>
<ThresholdFilter level="WARN" onMatch="ACCEPT" onMismatch="DENY"/>
</Filters>
<PatternLayout pattern="${PATTERN}" />
<Policies>
<TimeBasedTriggeringPolicy />
<SizeBasedTriggeringPolicy size="10 MB" />
</Policies>
<!-- DefaultRolloverStrategy属性如不设置，则默认为最多同一文件夹下7个文件，这里设置了20 -->
<DefaultRolloverStrategy max="20" />
</RollingFile>
</Appenders>
<!--定义logger，只有定义了logger并引入的appender，appender才会生效-->
<Loggers>
<!--Logger节点用来单独指定日志的形式，name为包路径,好比要为org.springframework包下全部日志指定为ERROR级别等。 -->
<logger name="org.apache.ibatis" additivity="false" level="ERROR" />
<logger name="org.apache.shiro" additivity="false" level="ERROR" />
<logger name="net.sf.ehcache" additivity="false" level="ERROR" />
<logger name="org.apache.commons" additivity="false" level="ERROR" />
<logger name="org.mybatis.spring" additivity="false" level="ERROR" />
<logger name="java.sql" additivity="false" level="ERROR" />
<logger name="org.springframework" additivity="false" level="ERROR" />
<logger name="com.alibaba.druid.filter.stat" additivity="false" level="WARN" />
<logger name="com.alibaba.druid.pool" additivity="false" level="WARN" />
<logger name="druid.sql.Connection" additivity="false" level="WARN" />
<logger name="druid.sql.DataSource" additivity="false" level="WARN" />
<logger name="druid.sql.ResultSet" additivity="false" level="WARN" />
<logger name="druid.sql.Statement" additivity="false" level="WARN" />
<!-- Root节点用来指定项目的根日志，若是没有单独指定Logger，那么就会默认使用该Root日志输出 -->
<Root level="INFO">
<AppenderRef ref="Console" />
<AppenderRef ref="DebugAppender" />
<AppenderRef ref="InfoAppender" />
<AppenderRef ref="ErrorAppender" />
</Root>
</Loggers>
</Configuration>
若是你的项目中使用的是老的框架，使用的是web.xml，那还要去修改
四、修改web.xmlapache
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
version="2.5">
<!--日志升级开始-->
<listener>
<listener-class>org.apache.logging.log4j.web.Log4jServletContextListener</listener-class>
</listener>
<filter>
<filter-name>log4jServletFilter</filter-name>
<filter-class>org.apache.logging.log4j.web.Log4jServletFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>log4jServletFilter</filter-name>
<url-pattern>/*</url-pattern>
<dispatcher>REQUEST</dispatcher>
<dispatcher>FORWARD</dispatcher>
<dispatcher>INCLUDE</dispatcher>
<dispatcher>ERROR</dispatcher>
</filter-mapping>
<context-param>
<param-name>log4jContextName</param-name>
<param-value>myApplication</param-value>
</context-param>
<context-param>
<param-name>log4jConfiguration</param-name>
<param-value>classpath:log4j2.properties</param-value>
</context-param>
<!--日志升级结束-->
在web.xml中移除旧的log4j.property的配置后端
<context-param>
<param-name>log4jConfigLocation</param-name>
<param-value>classpath:log4j.properties</param-value>
</context-param>
五、log4j2测试
使用的LogManager.getLogger(Object.class)方式获取对象api
加入测试类，并运行。如在项目磁盘目录下正常输出日志内容则说明log4j2添加成功mybatis
public class TestLogger {
private static final Logger log = LoggerFactory.getLogger(TestLogger.class);
public static void main(String[] args) {
int num=10;
log.info("8888888888888888Info : numis " + num);
log.warn("8888888888888888Warning : numis " + num);
log.debug("8888888888888888Debug : numis " + num);
log.error("8888888888888888Error : numis " + num);
}
}