Apache Maven profile详解和资源属性过滤

1. 概述

profile有侧面的含义，项目有很多个运行环境，比如开发环境、测试环境、生产环境，每一个运行环境相当于是项目整体的一个侧面

所以profile可以给不同的运行环境定义不同的pom配置属性，然后根据需要激活一个运行环境

2. 默认profile

pom.xml中，project标签下除了modelVersion和module的坐标标签之外，其它标签都是在设定默认的profile。所以其它标签都可以配置到我们自己定义的profile中

3. profile配置

profile可以在下面两种配置文件中配置：

• settings.xml：全局生效。比如全局配置JDK 1.11
• pom.xml：当前POM生效

语法要求：

• profiles/profile标签

由于profile标签覆盖了pom.xml中的默认配置，所以profiles标签通常是pom.xml中的最后一个标签

• id标签

每个profile都必须有一个id标签，指定该profile的唯一标识。这个id标签的值会在命令行调用profile时被用到。这个命令格式是：-Pprofile id

• 其它允许出现的标签

一个profile可以覆盖项目的最终名称、项目依赖、插件配置等各个方面以影响构建行为

build
    defaultGoal
    finalName
    resources
    testResources
    plugins
reporting
modules
dependencies
dependencyManagement
repositories
pluginRepositories
properties

4. 激活profile 4.1 基于环境信息激活

环境信息包含：JDK 版本、操作系统参数、文件、属性等各个方面。一个profile 一旦被激活，那么它定义的所有配置都会覆盖原来POM中对应层次的元素。可以参考下面的标签结构

  
    
      
      dev

      
      
        
        false
        11
        
          windows 10
          windows
          amd64
          10.0
        
        
          mavenVersion
          3.8.6
        
        
          test1.properties
          test2.properties
        
      

      
      
        
          
            
              maven-resources-plugin
              3.2.0
            
          
        
      
    
  

说明：

• 如果activeByDefault为false，需要activation里面的所有条件都符合，才能激活该profile
• Maven会自动检测当前环境安装的JDK版本，只要JDK版本是以11开头都算符合条件。比如这几个都符合：11.0.1、11.0.15

4.2 命令行激活

列出活动的profile，以及它们在哪里定义

C:\Users\dell\Desktop\maven-learn>mvn help:active-profiles
[INFO] Scanning for projects...
[INFO] 
[INFO] -------------------------< com.hh:maven-learn >-------------------------
[INFO] Building maven-learn 0.1
[INFO] --------------------------------[ jar ]---------------------------------
[INFO]
[INFO] --- maven-help-plugin:3.2.0:active-profiles (default-cli) @ maven-learn ---
[INFO] 
Active Profiles for Project 'com.hh:maven-learn:jar:0.1':

The following profiles are active:

 - jdk-11 (source: external)



[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  0.922 s
[INFO] Finished at: 2022-06-30T21:25:24+08:00
[INFO] ------------------------------------------------------------------------

C:\Users\dell\Desktop\maven-learn>

这是我们在settings.xml中定义了一个id为jdk-11的profile，且默认激活

指定某个具体profile进行激活。这里我们以上面定义的profile为例

C:\Users\dell\Desktop\maven-learn>mvn compile -Pdev
[INFO] Scanning for projects...
[INFO] 
[INFO] -------------------------< com.hh:maven-learn >-------------------------
[INFO] Building maven-learn 0.1
[INFO] --------------------------------[ jar ]---------------------------------
[INFO] 
[INFO] --- maven-resources-plugin:3.2.0:resources (default-resources) @ maven-learn ---
[WARNING] Using platform encoding (GBK actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] Using 'null' encoding to copy filtered properties files.
[INFO] skip non existing resourceDirectory C:\Users\dell\Desktop\maven-learn\src\main\resources
[INFO]
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ maven-learn ---
[INFO] Nothing to compile - all classes are up to date
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  0.973 s
[INFO] Finished at: 2022-06-30T21:32:21+08:00
[INFO] ------------------------------------------------------------------------

C:\Users\dell\Desktop\maven-learn>

如果不激活dev这个profile，默认使用的maven-resources-plugin插件是2.6版本的。激活后使用的maven-resources-plugin插件版本是我们在profile中定义的3.2.0

5. 资源属性过滤

Maven可以通过profile实现各种不同运行环境切换，提供了一种资源属性过滤的机制。通过属性替换实现不同环境使用不同的参数

定义profile如下：

  
    
      devJDBCProfile
      
        com.mysql.cj.jdbc.Driver
        http://localhost:3306/information_schema
        root
        Root_123
      
      
        
          
            
            true
            
            
            ${project.basedir}/src/main/resources
          
        
      
    
  

src/main/resources/jdbcTest.properties文件内容如下：

jdbc.driver=${dev.jdbc.driver}
jdbc.url=${dev.jdbc.url}
jdbc.user=${dev.jdbc.user}
jdbc.password=${dev.jdbc.password}

然后执行资源处理命令

C:\Users\dell\Desktop\maven-learn>mvn clean resources:resources -PdevJDBCProfile
[INFO] Scanning for projects...
[INFO] 
[INFO] -------------------------< com.hh:maven-learn >-------------------------
[INFO] Building maven-learn 0.1
[INFO] --------------------------------[ jar ]---------------------------------
[INFO]
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ maven-learn ---
[INFO] Deleting C:\Users\dell\Desktop\maven-learn\target
[INFO] 
[INFO] --- maven-resources-plugin:2.6:resources (default-cli) @ maven-learn ---
[WARNING] File encoding has not been set, using platform encoding GBK, i.e. build is platform dependent!
[WARNING] Using platform encoding (GBK actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] Copying 1 resource
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  0.633 s
[INFO] Finished at: 2022-06-30T21:50:51+08:00
[INFO] ------------------------------------------------------------------------

C:\Users\dell\Desktop\maven-learn>

生成的target/classes/jdbcTest.properties文件的内容如下：

jdbc.driver=com.mysql.cj.jdbc.Driver
jdbc.url=http://localhost:3306/information_schema
jdbc.user=root
jdbc.password=Root_123

6. 资源文件过滤

可以在resource标签下，使用includes和excludes标签，在resource阶段包含或排除一些资源文件

定义profile如下：

  
    
      devJDBCProfile
      
        
          
            
            true
            
            
            ${project.basedir}/src/main/resources
            
            
              *.txt
            
            
              test2.properties
            
          
        
      
    
  

src/main/resources目录下新建文件test1.txt和test2.properties

然后执行资源处理命令

C:\Users\dell\Desktop\maven-learn>mvn clean resources:resources -PdevJDBCProfile
[INFO] Scanning for projects...
[INFO] 
[INFO] -------------------------< com.hh:maven-learn >-------------------------
[INFO] Building maven-learn 0.1
[INFO] --------------------------------[ jar ]---------------------------------
[INFO]
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ maven-learn ---
[INFO] Deleting C:\Users\dell\Desktop\maven-learn\target
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-cli) @ maven-learn ---
[WARNING] File encoding has not been set, using platform encoding GBK, i.e. build is platform dependent!
[WARNING] Using platform encoding (GBK actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] Copying 1 resource
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  0.563 s
[INFO] Finished at: 2022-06-30T21:59:47+08:00
[INFO] ------------------------------------------------------------------------

C:\Users\dell\Desktop\maven-learn>

在target/classes目录下，只有test1.txt