maven的pom.xml用<exclusion>解决版本问题

 用maven管理库依赖，有个好处就是连同库的依赖的全部jar文件一起下载，免去手工添加的麻烦，但同时也带来了同一个jar会被下载了不同版本的问题，好在pom的配置里面允许用<exclusion>来排除一些不需要同时下载的依赖jar 。

 

<!-- Struts2 -->

<dependency>

<groupId>org.apache.struts</groupId>

<artifactId>struts2-core</artifactId>

<version>${struts.version}</version>

<exclusions>

<exclusion>

<groupId>javassist</groupId>

<artifactId>javassist</artifactId>

</exclusion>

<exclusion> <!-- we prefer our explicit version, though it should be the same -->

<groupId>asm</groupId>

<artifactId>asm</artifactId>

</exclusion>

<exclusion> <!-- we prefer our explicit version, though it should be the same -->

<groupId>asm</groupId>

<artifactId>asm-commons</artifactId>

</exclusion>

<exclusion> <!-- we prefer our explicit version, though it should be the same -->

<groupId>org.ow2.asm</groupId>

<artifactId>asm</artifactId>

</exclusion>

<exclusion> <!-- we prefer our explicit version, though it should be the same -->

<groupId>org.ow2.asm</groupId>

<artifactId>asm-commons</artifactId>

</exclusion>

</exclusions>

</dependency>