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>