Apache Maven help插件介绍和pom.xml中进行property属性的定义、引用

1. help插件和目标

详细的使用请参考官网：https://maven.apache.org/plugins/maven-help-plugin

目标说明help:active-profiles列出当前工程已激活的profilehelp:all-profiles列出当前工程所有可用profilehelp:describe描述一个插件和Mojo(Maven Old Java Object，插件的一个执行目标)的属性help:effective-pom以XML格式展示有效POMhelp:effective-settings为当前工程以XML格式展示计算得到的settings配置help:evaluate在交互模式下对Maven表达式进行计算help:system显示平台详细信息列表，如系统属性和环境变量 2. 使用help:evaluate查看属性值 2.1 查看pom.xml定义的property

在pom.xml中定义的property如下

  
    my-value
  

然后交互式的查看属性值

C:\Users\dell\Desktop\maven-learn>mvn help:evaluate
[INFO] Scanning for projects...
[INFO]
[INFO] -------------------------< com.hh:maven-learn >-------------------------
[INFO] Building my-project 0.1
[INFO] --------------------------------[ jar ]---------------------------------
[INFO]
[INFO] --- maven-help-plugin:3.2.0:evaluate (default-cli) @ maven-learn ---
[INFO] No artifact parameter specified, using 'com.hh:maven-learn:jar:0.1' as project.
[INFO] Enter the Maven expression i.e. ${project.groupId} or 0 to exit?:
${my-key}
[INFO]
my-value
[INFO] Enter the Maven expression i.e. ${project.groupId} or 0 to exit?:

2.2 查看系统的属性值

可以获取系统的属性值，也就是Java中的System.getProperties()可以获取到的属性

[INFO] Enter the Maven expression i.e. ${project.groupId} or 0 to exit?:
${java.runtime.version}
[INFO]
11.0.15+10-LTS
[INFO] Enter the Maven expression i.e. ${project.groupId} or 0 to exit?:

2.3 查看系统的环境变量

[INFO] Enter the Maven expression i.e. ${project.groupId} or 0 to exit?:
${env.JAVA_HOME}
[INFO]
d:install_software\java11\zulu11.56.19-ca-jdk11.0.15-win_x64
[INFO] Enter the Maven expression i.e. ${project.groupId} or 0 to exit?:

2.4 查看project的pom.xml中的属性值

使用表达式${project.xxx}可以访问当前pom.xml中的元素值

[INFO] Enter the Maven expression i.e. ${project.groupId} or 0 to exit?:
${project.organization.name}
[INFO]
my-company
[INFO] Enter the Maven expression i.e. ${project.groupId} or 0 to exit?:
${project.licenses[0]}
[INFO]

  Apache License, Version 2.0
  https://www.apache.org/licenses/LICENSE-2.0
  
    55
    14
    
      com.hh:maven-learn:0.1
      C:\Users\dell\Desktop\maven-learn\pom.xml
    
  
  
    56
    13
    
  
  
    57
    12
    
  

[INFO] Enter the Maven expression i.e. ${project.groupId} or 0 to exit?:

2.5 访问maven的settings.xml中的属性值

[INFO] Enter the Maven expression i.e. ${project.groupId} or 0 to exit?:
${settings.localRepository}
[INFO]
D:\install_software\maven\apache-maven-3.8.6\repository
[INFO] Enter the Maven expression i.e. ${project.groupId} or 0 to exit?: