将应用的log4j换成logback

考虑到log4j很久不更新、性能相对弱，以及一些项目本身的原因，经过较为谨慎的考虑，决定改用logback。迁移还是比较顺利的，花了1个小时左右就搞定了，做个简单的笔记。

(1) 首先去掉所有log4j相关的依赖，主要有：

<dependency>  <groupId>log4j</groupId>  <artifactId>log4j</artifactId></dependency>

以及：

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

(2) 为项目添加以下依赖：

<!-- logback日志配置开始 --><dependency>  <groupId>ch.qos.logback</groupId>  <artifactId>logback-core</artifactId></dependency><dependency>  <groupId>ch.qos.logback</groupId>  <artifactId>logback-access</artifactId></dependency><dependency>  <groupId>ch.qos.logback</groupId>  <artifactId>logback-classic</artifactId></dependency><dependency>  <groupId>org.slf4j</groupId>  <artifactId>log4j-over-slf4j</artifactId></dependency><!-- logback日志配置结束 -->

(3) 删除项目/src/main/resources目录下的log4j.properties，并在该目录添加logback.xml文件，logback.xml文件如下：

<?xml version="1.0" encoding="UTF-8"?><configuration>    <appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">        <Target>System.out</Target>        <encoder>            <pattern>%date [%level] [%thread] %logger{80} [%file : %line] %msg%n</pattern>        </encoder>    </appender>    <appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">        <encoder>            <pattern>%date [%level] [%thread] %logger{80} [%file : %line] %msg%n</pattern>        </encoder>        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">            <fileNamePattern>${catalina.home}/logs/yzf/sql%d{yyyy-MM-dd}.log</fileNamePattern>            <!-- 保留 30天数据，默认无限-->            <MaxHistory>30</MaxHistory>        </rollingPolicy>    </appender>    <logger name="org.springframework" level="INFO" />    <logger name="org.apache" level="INFO" />    <logger name="com.itmuch" level="WARN" />    <root level="INFO">        <appender-ref ref="CONSOLE" />        <appender-ref ref="FILE" />    </root></configuration>

TIPS

(1) log4j-over-slf4j与slf4j-log4j12不能共存，可能会引发异常，详见http://www.tuicool.com/articles/INveIf 。

(2) slf4j-api、slf4j-log4j12以及log4j之间的关系http://blog.csdn.net/tengdazhang770960436/article/details/18006127

(3) 参考文档：http://blog.csdn.net/chenminghe271/article/details/38682493