maven中的传递依赖和传递依赖的解除

例如创建三个maven工程A B C

pom文件分别为

A

 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
   <modelVersion>4.0.0</modelVersion>

   <groupId>org.lonecloud.A</groupId>
   <artifactId>A</artifactId>
   <version>0.0.1-SNAPSHOT</version>
   <packaging>jar</packaging>

   <name>A</name>
   <url>http://maven.apache.org</url>

   <properties>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
   </properties>

   <dependencies>
     <dependency>
       <groupId>junit</groupId>
       <artifactId>junit</artifactId>
       <version>3.8.1</version>
       <scope>test</scope>
     </dependency>
   </dependencies>
 </project>

B

 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>

     <groupId>org.lonecloud.B</groupId>
     <artifactId>B</artifactId>
     <version>0.0.1-SNAPSHOT</version>
     <packaging>jar</packaging>

     <name>B</name>
     <url>http://maven.apache.org</url>

     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     </properties>

     <dependencies>
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>
             <version>3.8.1</version>
             <scope>test</scope>
         </dependency>
         <!-- B依赖于A -->
         <dependency>
             <groupId>org.lonecloud.A</groupId>
             <artifactId>A</artifactId>
             <version>0.0.1-SNAPSHOT</version>
         </dependency>
     </dependencies>
 </project>

C

 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>

     <groupId>org.lonecloud.C</groupId>
     <artifactId>C</artifactId>
     <version>0.0.1-SNAPSHOT</version>
     <packaging>jar</packaging>

     <name>C</name>
     <url>http://maven.apache.org</url>

     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     </properties>

     <dependencies>
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>
             <version>3.8.1</version>
             <scope>test</scope>
         </dependency>
         <!--C依赖于B但是会将A的依赖传递进来 -->
         <dependency>
             <groupId>org.lonecloud.B</groupId>
             <artifactId>B</artifactId>
             <version>0.0.1-SNAPSHOT</version>
         </dependency>
     </dependencies>
 </project>

当我只需要B的依赖而不需要A的依赖的时候可以使用

            <!-- 此标签的作用是可以将B的传递依赖关系A不传递给C -->
            <exclusions>
                <exclusion>
                    <groupId>org.lonecloud.A</groupId>
                    <artifactId>A</artifactId>
                </exclusion>
            </exclusions>

排除对A的依赖