Maven进阶笔记

适用人群

• 对maven有一些基本的概念，会一些日常的操作
• 希望深入了解maven的概念和机制，解释一些底层的细节

生命周期、阶段、插件、目标

• mvn clean dependency:copy-dependencies package

  • 执行clean生命周期中clean阶段之前(包括)所有的阶段
  • 执行 dependency插件copy-dependencies这个目标
  • 执行default生命周期中package阶段之前(包括)所有的阶段

• clean

  
      pre-clean
      clean
      post-clean
   
  
      
        org.apache.maven.plugins:maven-clean-plugin:2.5:clean
      
  
  

• default

    
      validate
      initialize
      generate-sources
      process-sources
      generate-resources
      process-resources
      compile
      process-classes
      generate-test-sources
      process-test-sources
      generate-test-resources
      process-test-resources
      test-compile
      process-test-classes
      test
      prepare-package
      package
      pre-integration-test
      integration-test
      post-integration-test
      verify
      install
      deploy
  
  

• site

  
      pre-site
      site
      post-site
      site-deploy
  
  
      
        org.apache.maven.plugins:maven-site-plugin:3.3:site
      
      
        org.apache.maven.plugins:maven-site-plugin:3.3:deploy
      
  
  

不同打包类型绑定的阶段、插件和目标

• pom

  
      
        org.apache.maven.plugins:maven-install-plugin:2.4:install
      
      
        org.apache.maven.plugins:maven-deploy-plugin:2.7:deploy
      
  
  

• jar

  
      
        org.apache.maven.plugins:maven-resources-plugin:2.6:resources
      
      
        org.apache.maven.plugins:maven-compiler-plugin:3.1:compile
      
      
        org.apache.maven.plugins:maven-resources-plugin:2.6:testResources
      
      
        org.apache.maven.plugins:maven-compiler-plugin:3.1:testCompile
      
      
        org.apache.maven.plugins:maven-surefire-plugin:2.12.4:test
      
      
        org.apache.maven.plugins:maven-jar-plugin:2.4:jar
      
      
        org.apache.maven.plugins:maven-install-plugin:2.4:install
      
      
        org.apache.maven.plugins:maven-deploy-plugin:2.7:deploy
      
  
  
  

• war

  
      
        org.apache.maven.plugins:maven-resources-plugin:2.6:resources
      
      
        org.apache.maven.plugins:maven-compiler-plugin:3.1:compile
      
      
        org.apache.maven.plugins:maven-resources-plugin:2.6:testResources
      
      
        org.apache.maven.plugins:maven-compiler-plugin:3.1:testCompile
      
      
        org.apache.maven.plugins:maven-surefire-plugin:2.12.4:test
      
      
        org.apache.maven.plugins:maven-war-plugin:2.2:war
      
      
        org.apache.maven.plugins:maven-install-plugin:2.4:install
      
      
        org.apache.maven.plugins:maven-deploy-plugin:2.7:deploy
      
  
  

POM(Project Object Model)

• Super POM

  • 位置 $MAVEN_HOME/lib/maven-model-builder-x.y.z.jar!/org/apache/maven/model/pom-4.0.0.xml

  
  4.0.0
  
  
    
      central
      Central Repository
      http://repo.maven.apache.org/maven2
      default
      
        false
      
    
  
  
  
    
      central
      Central Repository
      http://repo.maven.apache.org/maven2
      default
      
        false
      
      
        never
      
    
  
  
  
    ${project.basedir}/target
    ${project.build.directory}/classes
    ${project.artifactId}-${project.version}
    ${project.build.directory}/test-classes
    ${project.basedir}/src/main/java
    src/main/scripts
    ${project.basedir}/src/test/java
    
      
        ${project.basedir}/src/main/resources
      
    
    
      
        ${project.basedir}/src/test/resources
      
    
    
      
      
      
        
          maven-antrun-plugin
          1.3
        
        
          maven-assembly-plugin
          2.2-beta-5
        
        
          maven-dependency-plugin
          2.1
        
        
          maven-release-plugin
          2.0
        
      
    
  
  
  
    ${project.build.directory}/site
  
  
  
    
    
      release-profile
  
      
        
          performRelease
          true
        
      
  
      
        
          
            true
            maven-source-plugin
            
              
                attach-sources
                
                  jar
                
              
            
          
          
            true
            maven-javadoc-plugin
            
              
                attach-javadocs
                
                  jar
                
              
            
          
          
            true
            maven-deploy-plugin
            
              true
            
          
        
      
    
  
  
  
  

  • 继承和聚合

  
      4.0.0
     
      
            com.mycompany.app
            my-app
            1
      
     
      my-module
  
  

  
      4.0.0
     
      com.mycompany.app
      my-app
      1
      pom
     
      
            my-module
      
  
  

• 内置properties

value	evaluation result	common examples
project.*	POM content(参考 Super POM)	{project.build.finalName} {project.build.directory}
project.basedir	the directory containing the pom.xml file	${project.basedir}
project.baseUri	the directory containing the pom.xml file as URI	${project.baseUri}
build.timestamp maven.build.timestamp	the UTC timestamp of build start, in yyyy-MM-dd'T'HH:mm:ss'Z' default format, which can be overridden with maven.build.timestamp.format POM property	${maven.build.timestamp}
*	user properties, set from CLI with -Dproperty=value	${skipTests}
*	model properties, such as project properties set in the pom	${any.key}
maven.home	The path to the current Maven home.	${maven.home}
maven.version	The version number of the current Maven execution (since 3.0.4). For example, "3.0.5".	${maven.version}
maven.build.version	The full build version of the current Maven execution (since 3.0.4). For example, "Apache Maven 3.2.2 (r01de14724cdef164cd33c7c8c2fe155faf9602da; 2013-02-19T14:51:28+01:00)".	${maven.build.version}
maven.repo.local	The repository on the local machine Maven shall use to store installed and downloaded artifacts (POMs, JARs, etc).	${user.home}/.m2/repository
*	Java system properties(see JDK reference)	{java.home}
env.* *	environment variables	${env.PATH}
settings.*	Local user settings (see settings reference)	${settings.localRepository}

依赖管理

• 解决依赖冲突，最近原则

  • D 1.0 生肖

    A
  ├── B
  │   └── C
  │       └── D 2.0
  └── E
      └── D 1.0
  

  • D 3.0 生效

    A
  ├── B
  │   └── C
  │       └── D 2.0
  ├── E
  │   └── D 1.0
  │
  └── D 3.0    
  │
  └── D 4.0    
  

• scope

  • compile 默认类型 参与所有机制

  • provided 代表由环境提供，不用在打包时包含

  • runtime 只在运行时需要，不参与编译

  • test 只在测试代码中需要

  • system 类似provided 不从maven仓库拿包，从系统路径拿包

  • import 特殊类型，只导入dependencyManagement

  • 不同类型的生效关系

  scope\生效阶段	编译时	测试	运行时	传递依赖
  compile	✓	✓	✓	✓
  provided	✓	✓	✕	✕
  runtime	✕	✓	✓	✓
  test	✕	✓	✕	✕
  system	✓	✓	✕	✕

  • 上层依赖scope与传递依赖冲突时的判定

  上层scope\传递依赖	compile	provided	runtime	test
  compile	compile	-	runtime	-
  provided	provided	-	provided	-
  runtime	runtime	-	runtime	-
  test	test	-	test	-

• type

  • pom
  • jar
  • maven-plugin
  • ebb
  • war
  • ear
  • rar
  • java-source
  • javadoc
  • ejb-client
  • test-jar

• classifier

  • sources
  • javadoc
  • client
  • tests

• 最小粒度依赖 {groupId, artifactId, type, classifier}

• 默认依赖 {groupId, artifactId, 'jar', null}

• 阻止传递依赖

  • 被动: optional B->C(optional) A->B-✕(C)
  • 主动: exclusion

仓库配置

• 仓库加载顺序

  • $maven_home/conf/settings.xml
  • $user_home/.m2/settings.xml
  • local pom
  • parent pom
  • super pom
  • dependency pom

• 镜像，替换某个(某些)仓库

  • 替换中央仓库(mirrorOf)

  
    
      other-mirror
      Other Mirror Repository
      https://other-mirror.repo.other-company.com/maven2
      central