都知道 Maven 在出现依赖版本冲突问题时,会用最短路径原则和第一声明原则来解决冲突。但在自己电脑上引入如下依赖,却产生了与期望违背的效果:
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.6</version>
</dependency>
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.4</version>
</dependency>
按照两个原则的话,最终引入的应该是版本为 2.6 的包,但实际却引入了版本为 2.4 的包。分析如下:
> mvn dependency:tree
[INFO] ------------------------------------------------------------------------
[INFO] Building mvn-test 1.0.0
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-dependency-plugin:2.8:tree (default-cli) @ mvn-yilaitest ---
[INFO] com.ariclee:mvn-yilaitest:jar:1.0.0
[INFO] \- commons-io:commons-io:jar:2.4:compile
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.068 s
[INFO] Finished at: 2019-05-11T16:45:38+08:00
[INFO] Final Memory: 12M/245M
[INFO] ------------------------------------------------------------------------
为什么依赖后声明的却被引入了,这不是违背了第一声明原则吗?