升级log4j2遇到的那些坑

<slf4j.version>1.7.13</slf4j.version>
<log4j2.version>2.3</log4j2.version>
<disruptor.version>3.3.2</disruptor.version>
<spring.version>3.2.4.RELEASE</spring.version>

<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-api</artifactId>
<version>${log4j2.version}</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-core</artifactId>
<version>${log4j2.version}</version>
</dependency>
<dependency>
<groupId>com.lmax</groupId>
<artifactId>disruptor</artifactId>
<version>${disruptor.version}</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>${slf4j.version}</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-slf4j-impl</artifactId>
<version>${log4j2.version}</version>
</dependency>

<!--这块比较关键，Spring原生应用中需要用到commons-logging，需要把它exclude掉，另外引入jcl-over-slf4j-->
<!--你会发现jcl-over-slf4j 只是改写了commons-logging 去兼容Spring-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<exclusions>
<exclusion>
<artifactId>commons-logging</artifactId>
<groupId>commons-logging</groupId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>jcl-over-slf4j</artifactId>
<version>1.7.13</version>
<scope>runtime</scope>
</dependency>

<!-- 如果代码中依赖的jar包用到了log4j1.2.X,当工程中将log4j1.2.X排除掉了之后，项目启动时会报错不成功的 -->
<!-- 把下面这个jar引入进来就OK了 -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>log4j-over-slf4j</artifactId>
<version>${slf4j.version}</version>
</dependency>