Jar包冲突
NoSuchMethodError ClassNotFoundException


依赖传递
最短路径优先
最先声明优先

mvn dependency:tree -Dverbose



exclude

<exclusions>
    <exclusion>
        <groupId>x.y</groupId>
        <artifactId>z</artifactId>
    </exclusion>
</exclusions>


版本锁定
dependencyManagement

<dependencyManagement>
    <dependency>
        <groupId>x.y</groupId>
        <artifactId>z</artifactId>
        <version>1.0.0</version>
    </dependency>
</dependencyManagement>


在父POM中定义 dependencyManagement
去掉不必要的依赖
mvn dependency:analyze-only       
    Used undeclared dependencies
    Unused declared dependencies

mvn dependency:analyze-duplicate  重复的依赖