maven的聚合模块和pom继承使用(六)
转载请注明出处哈:http://yanan0628.iteye.com/blog/2270411
1.什么是maven的聚合模块?
聚合模块为项目目录的最顶层,其他模块作为聚合模块子目录而存在。目的是为一次构建多个项目模块。
1.1 项目结构
我自己化了一个关于项目的关系:
1.2 pom标签配置-module
maven-aggregate作为maven pom项目,需要定义pom.xml的 packaging 为 pom类型
我们还是参照 maven的依赖特性,冲突解决(五) 创建 maven-01 maven-02 maven-03工程,通过maven-aggregate pom工程 对这三个maven项目做一个聚合,配置如下:
<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>com.sohu.train</groupId> <artifactId>maven-aggregate</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>pom</packaging> <!-- 子模块 指定项目pom的位置 ..代表上一级目录--> <modules> <module>../maven-01</module> <module>../maven-02</module> <module>..maven-03</module> </modules> </project>
对 maven-aggregate执行下mvn clean compile
[INFO] Scanning for projects... [WARNING] [WARNING] Some problems were encountered while building the effective model for com.sohu.train:maven-02:jar:1.0-SNAPSHORT [WARNING] 'dependencies.dependency.exclusions.exclusion.groupId' for junit:junit:jar is missing. @ line 38, column 16 [WARNING] 'dependencies.dependency.exclusions.exclusion.artifactId' for junit:junit:jar is missing. @ line 38, column 16 [WARNING] [WARNING] It is highly recommended to fix these problems because they threaten the stability of your build. [WARNING] [WARNING] For this reason, future Maven versions might no longer support building such malformed projects. [WARNING] [INFO] ------------------------------------------------------------------------ [INFO] Reactor Build Order: //构建 maven 的反应堆,执行清理 编译的顺序 [INFO] [INFO] maven-02 [INFO] maven-01 [INFO] maven-03 [INFO] maven-aggregate [INFO] [INFO] ------------------------------------------------------------------------ [INFO] Building maven-02 1.0-SNAPSHORT [INFO] ------------------------------------------------------------------------ [INFO] [INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ maven-02 --- [INFO] Deleting E:\train\test\maven-02\target [INFO] [INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ maven-02 --- [INFO] Using 'UTF-8' encoding to copy filtered resources. [INFO] skip non existing resourceDirectory E:\train\test\maven-02\src\main\resources [INFO] [INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ maven-02 --- [INFO] Changes detected - recompiling the module! [INFO] Compiling 1 source file to E:\train\test\maven-02\target\classes [INFO] [INFO] ------------------------------------------------------------------------ [INFO] Building maven-01 1.0-SNAPSHOT [INFO] ------------------------------------------------------------------------ [INFO] [INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ maven-01 --- [INFO] Deleting E:\train\test\maven-01\target [INFO] [INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ maven-01 --- [INFO] Using 'UTF-8' encoding to copy filtered resources. [INFO] Copying 1 resource [INFO] [INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ maven-01 --- [INFO] Changes detected - recompiling the module! [INFO] Compiling 1 source file to E:\train\test\maven-01\target\classes [INFO] [INFO] ------------------------------------------------------------------------ [INFO] Building maven-03 0.0.1-SNAPSHOT [INFO] ------------------------------------------------------------------------ [INFO] [INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ maven-03 --- [INFO] Deleting E:\train\test\maven-03\target [INFO] [INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ maven-03 --- [INFO] Using 'UTF-8' encoding to copy filtered resources. [INFO] skip non existing resourceDirectory E:\train\test\maven-03\src\main\resources [INFO] [INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ maven-03 --- [INFO] Changes detected - recompiling the module! [INFO] Compiling 1 source file to E:\train\test\maven-03\target\classes [INFO] [INFO] ------------------------------------------------------------------------ [INFO] Building maven-aggregate 0.0.1-SNAPSHOT [INFO] ------------------------------------------------------------------------ [INFO] [INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ maven-aggregate --- [INFO] ------------------------------------------------------------------------ [INFO] Reactor Summary: // 可以看到 对3个maven项目 一起执行编译 [INFO] [INFO] maven-02 ........................................... SUCCESS [ 1.874 s] [INFO] maven-01 ........................................... SUCCESS [ 0.108 s] [INFO] maven-03 ........................................... SUCCESS [ 0.158 s] [INFO] maven-aggregate .................................... SUCCESS [ 0.002 s] [INFO] ------------------------------------------------------------------------ [INFO] BUILD SUCCESS [INFO] ------------------------------------------------------------------------ [INFO] Total time: 2.263 s [INFO] Finished at: 2016-01-15T14:35:41+08:00 [INFO] Final Memory: 14M/227M [INFO] ------------------------------------------------------------------------这样我们就完成 maven对子模块的聚合 ,像我们平常用的dubbo jetty tomcat spring hibernate等等 都是按模块 去开发,一次编译 各个模块都能紧密联系在一起了。我们在平常开发项目也需要适当的去分模块开发,
这是dubbo的子模块,分了很多子模块:
2.什么是pom继承?
pom继承是为了抽出重复配置,通常配置在父模块中,为子模块提供使用,这样可以做到“一处声明,处处使用”。
2.1 继承结构
2.2 pom标签配置-parent,*Management
1.常用的pom被继承的元素
groupId :项目组 ID ,项目坐标的核心元素; version :项目版本,项目坐标的核心元素; description :项目的描述信息; properties :自定义的 Maven 属性; dependencies :项目的依赖配置; dependencyManagement :醒目的依赖管理配置; repositories :项目的仓库配置; build :包括项目的源码目录配置、输出目录配置、插件配置、插件管理配置等;
1.配置maven-aggregate pom文件:
<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>com.sohu.train</groupId> <artifactId>maven-aggregate</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>pom</packaging> <!-- 子模块 --> <modules> <module>../maven-01</module> <module>../maven-02</module> <module>../maven-03</module> </modules> <!-- 统一配置构件的版本号 --> <properties> <junit.version>3.8.1</junit.version> </properties> <!-- 依赖管理 --> <dependencyManagement> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>${junit.version}</version> <scope>test</scope> </dependency> </dependencies> </dependencyManagement> </project>
maven-01,maven-02,maven-03 需要配置parent ,dependencies,同时对junit做一个依赖,3个工程的pom配置如下:
<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> <!-- 指定父pom的坐标及pom位置 --> <parent> <groupId>com.sohu.train</groupId> <artifactId>maven-aggregate</artifactId> <version>0.0.1-SNAPSHOT</version> <relativePath>../maven-aggregate/pom.xml</relativePath> </parent> <artifactId>maven-03</artifactId> <packaging>jar</packaging> <!-- 添加对junit依赖,这样公用配置只需要在maven-aggregate中去配置 --> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> </dependency> </dependencies> </project>
这样就完成pom的继承,讲公用的jar一次配置,就可以实现多处引用了。
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