maven 是用来构建项目结构的，是一种主流的项目构建工具，项目中使用到的第三方jar包，用maven来管理是非常方便的，本篇文章主要来讲解<dependencyManagement> 和 <dependencies> 在管理jar包方面的不同之处，对于maven的基础信息和其他的一些方面不再做介绍。
现在的项目基本上都是使用多module来管理的，这就涉及到一个问题，多module之间如何使用共同的第三方jar,或者说如何减少相同的jar导入的配置。
1. 首先介绍<dependencies>
我们是这里引入了一个jar包之后，这里如果没有加上version版本号的话，那么maven就会去<dependencyManagement>里找对应groupId和artifactId的jar,如果有就继承他，如果没有就会报错，这时候其实在我们配置的本地仓库中会真实的下载对应的jar包，这时候所有的子module都会默认继承这里面所有声明的jar
2. <dependencyManagement>
这里其实是起到管理依赖jar版本号的作用，一般只会在项目的最顶层的pom.xml中使用到，所有子module如果想要使用到这里面声明的jar，只需要在子module中添加相应的groupId和artifactId即可，并不需要声明版本号，需要注意的是这里面只是声明一个依赖，并不是真实的下载jar，只有在子module中使用到，才会去下载依赖。
<properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <druid.version>1.0.1</druid.version> <mysql.version>5.1.26</mysql.version> <spring.version>4.3.12.RELEASE</spring.version> <mybatis.version>3.4.5</mybatis.version> <mybatis-spring.version>1.3.0</mybatis-spring.version> <pagehelper.version>4.1.6</pagehelper.version> <gson.version>2.2.4</gson.version> <guava.version>15.0</guava.version> <dubbo.version>2.5.3</dubbo.version> <zookeeper.version>3.4.8</zookeeper.version> <zkclient.version>0.8</zkclient.version> <commons-lang.version>2.6</commons-lang.version> <shiro.version>1.2.3</shiro.version> <freemarker.version>2.3.22</freemarker.version> <commons-beanutils.version>1.9.2</commons-beanutils.version> <junit.version>4.12</junit.version> <mockito.version>1.10.19</mockito.version> <commons-collections4.version>4.1</commons-collections4.version> <httpclient.version>4.5.5</httpclient.version> <fastjson.version>1.2.37</fastjson.version> <jedis.version>2.9.0</jedis.version> <redis.version>1.8.8.RELEASE</redis.version> <jdk.version>1.8</jdk.version> <commons-logging.version>1.1</commons-logging.version> <log4j.version>1.2.17</log4j.version> <javax.servlet.version>2.5</javax.servlet.version> <activemq-core.version>5.7.0</activemq-core.version> <activemq-pool.version>5.12.1</activemq-pool.version> <spring.jms.version>5.0.6.RELEASE</spring.jms.version> <aspectj.version>1.8.0</aspectj.version> <jms.version>2.0.1</jms.version> <cglig.version>3.2.4</cglig.version> <!-- 设置默认编码 --> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <center.project.name>${project.artifactId}</center.project.name> <profiles.dir>src/profiles</profiles.dir> </properties>
<dependencyManagement> <dependencies> <!-- Aspectj --> <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjweaver</artifactId> <version>${aspectj.version}</version> </dependency> <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjrt</artifactId> <version>${aspectj.version}</version> </dependency> <dependency> <groupId>cglib</groupId> <artifactId>cglib</artifactId> <version>${cglig.version}</version> </dependency> <!-- activemq --> <dependency> <groupId>org.apache.activemq</groupId> <artifactId>activemq-core</artifactId> <version>${activemq-core.version}</version> </dependency> <dependency> <groupId>org.apache.activemq</groupId> <artifactId>activemq-pool</artifactId> <version>${activemq-pool.version}</version> </dependency> <dependency> <groupId>javax.jms</groupId> <artifactId>javax.jms-api</artifactId> <version>${jms.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jms</artifactId> <version>${spring.jms.version}</version> </dependency> <!-- activemq --> <dependency> <groupId>javax.servlet</groupId> <artifactId>servlet-api</artifactId> <version>${javax.servlet.version}</version> </dependency> <dependency> <groupId>commons-logging</groupId> <artifactId>commons-logging</artifactId> <version>${commons-logging.version}</version> </dependency> <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>${log4j.version}</version> </dependency> <!-- spring --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-beans</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aop</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-web</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context-support</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-oxm</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-tx</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-test</artifactId> <version>${spring.version}</version> </dependency> <!-- spring --> <!-- db --> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> <version>${druid.version}</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>${mysql.version}</version> </dependency> <!-- db --> <!-- mybatis --> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>${mybatis.version}</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> <version>${mybatis-spring.version}</version> </dependency> <dependency> <groupId>com.github.pagehelper</groupId> <artifactId>pagehelper</artifactId> <version>${pagehelper.version}</version> </dependency> <!-- mybatis --> <!-- apache --> <dependency> <groupId>commons-lang</groupId> <artifactId>commons-lang</artifactId> <version>${commons-lang.version}</version> </dependency> <!-- apache --> <!-- commons-beanutils --> <dependency> <groupId>commons-beanutils</groupId> <artifactId>commons-beanutils</artifactId> <version>${commons-beanutils.version}</version> <exclusions> <exclusion> <groupId>commons-logging</groupId> <artifactId>commons-logging</artifactId> </exclusion> </exclusions> </dependency> <!-- commons-beanutils --> <!-- dubbo --> <dependency> <groupId>com.alibaba</groupId> <artifactId>dubbo</artifactId> <version>${dubbo.version}</version> <exclusions> <exclusion> <artifactId>spring</artifactId> <groupId>org.springframework</groupId> </exclusion> <exclusion> <artifactId>netty</artifactId> <groupId>org.jboss.netty</groupId> </exclusion> </exclusions> </dependency> <!-- dubbo --> <!-- zookeeper --> <dependency> <groupId>org.apache.zookeeper</groupId> <artifactId>zookeeper</artifactId> <version>${zookeeper.version}</version> </dependency> <dependency> <groupId>com.101tec</groupId> <artifactId>zkclient</artifactId> <version>${zkclient.version}</version> </dependency> <!-- zookeeper --> <!-- jedis--> <dependency> <groupId>redis.clients</groupId> <artifactId>jedis</artifactId> <version>${jedis.version}</version> </dependency> <dependency> <groupId>org.springframework.data</groupId> <artifactId>spring-data-redis</artifactId> <version>${redis.version}</version> </dependency> <!-- test start --> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>${junit.version}</version> <scope>test</scope> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-test</artifactId> <version>${spring.version}</version> <scope>test</scope> </dependency> <dependency> <groupId>org.mockito</groupId> <artifactId>mockito-core</artifactId> <version>${mockito.version}</version> <scope>test</scope> </dependency> <!-- test end --> <!-- google --> <dependency> <groupId>com.google.code.gson</groupId> <artifactId>gson</artifactId> <version>${gson.version}</version> </dependency> <!-- fastjson--> <dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>${fastjson.version}</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> <version>${druid.version}</version> </dependency> <dependency> <groupId>com.google.guava</groupId> <artifactId>guava</artifactId> <version>${guava.version}</version> </dependency> <!-- google --> <dependency> <groupId>org.apache.commons</groupId> <artifactId>commons-collections4</artifactId> <version>${commons-collections4.version}</version> </dependency> <dependency> <groupId>org.apache.httpcomponents</groupId> <artifactId>httpclient</artifactId> <version>${httpclient.version}</version> <exclusions> <exclusion> <groupId>commons-logging</groupId> <artifactId>commons-logging</artifactId> </exclusion> </exclusions> </dependency> </dependencies> </dependencyManagement>
<dependencies> <!-- Aspectj --> <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjweaver</artifactId> <version>${aspectj.version}</version> </dependency> <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjrt</artifactId> <version>${aspectj.version}</version> </dependency></dependencies>
关于去除某个dependency中某个依赖项
可以使用如下的方式
<dependency> <groupId>org.apache.httpcomponents</groupId> <artifactId>httpclient</artifactId> <version>${httpclient.version}</version> <exclusions> <exclusion> <groupId>commons-logging</groupId> <artifactId>commons-logging</artifactId> </exclusion> </exclusions> </dependency>