在代码中从maven的pom.xml中检索版本号的最简单方法是什么,即以编程方式?


当前回答

公认的答案可能是将版本号静态地放入应用程序的最佳和最稳定的方法,但实际上并没有回答最初的问题:如何从pom.xml检索工件的版本号?因此,我想提供一个替代方案,展示如何在运行时动态地做这件事:

您可以使用Maven本身。更确切地说,您可以使用Maven库。

<dependency>
  <groupId>org.apache.maven</groupId>
  <artifactId>maven-model</artifactId>
  <version>3.3.9</version>
</dependency>

然后在Java中这样做:

package de.scrum_master.app;

import org.apache.maven.model.Model;
import org.apache.maven.model.io.xpp3.MavenXpp3Reader;
import org.codehaus.plexus.util.xml.pull.XmlPullParserException;

import java.io.FileReader;
import java.io.IOException;

public class Application {
    public static void main(String[] args) throws IOException, XmlPullParserException {
        MavenXpp3Reader reader = new MavenXpp3Reader();
        Model model = reader.read(new FileReader("pom.xml"));
        System.out.println(model.getId());
        System.out.println(model.getGroupId());
        System.out.println(model.getArtifactId());
        System.out.println(model.getVersion());
    }
}

控制台日志如下:

de.scrum-master.stackoverflow:my-artifact:jar:1.0-SNAPSHOT
de.scrum-master.stackoverflow
my-artifact
1.0-SNAPSHOT

更新2017-10-31:为了回答Simon Sobisch的后续问题,我修改了这个例子:

package de.scrum_master.app;

import org.apache.maven.model.Model;
import org.apache.maven.model.io.xpp3.MavenXpp3Reader;
import org.codehaus.plexus.util.xml.pull.XmlPullParserException;

import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Application {
  public static void main(String[] args) throws IOException, XmlPullParserException {
    MavenXpp3Reader reader = new MavenXpp3Reader();
    Model model;
    if ((new File("pom.xml")).exists())
      model = reader.read(new FileReader("pom.xml"));
    else
      model = reader.read(
        new InputStreamReader(
          Application.class.getResourceAsStream(
            "/META-INF/maven/de.scrum-master.stackoverflow/aspectj-introduce-method/pom.xml"
          )
        )
      );
    System.out.println(model.getId());
    System.out.println(model.getGroupId());
    System.out.println(model.getArtifactId());
    System.out.println(model.getVersion());
  }
}

其他回答

假设你正在使用Java,你可以:

Create a .properties file in (most commonly) your src/main/resources directory (but in step 4 you could tell it to look elsewhere). Set the value of some property in your .properties file using the standard Maven property for project version: foo.bar=${project.version} In your Java code, load the value from the properties file as a resource from the classpath (google for copious examples of how to do this, but here's an example for starters). In Maven, enable resource filtering. This will cause Maven to copy that file into your output classes and translate the resource during that copy, interpreting the property. You can find some info here but you mostly just do this in your pom: <build> <resources> <resource> <directory>src/main/resources</directory> <filtering>true</filtering> </resource> </resources> </build>

你还可以获取其他标准属性,如project.name, project.description,甚至是你放在pom <properties>中的任意属性,等等。资源过滤与Maven概要文件相结合,可以在构建时为您提供可变的构建行为。当您在运行时使用-PmyProfile指定配置文件时,可以启用属性,然后可以在构建中显示这些属性。

在使用spring引导时,这个链接可能有用:https://docs.spring.io/spring-boot/docs/2.3.x/reference/html/howto.html#howto-properties-and-configuration

使用spring-boot-starter-parent,你只需要在你的应用配置文件中添加以下内容:

# get values from pom.xml
pom.version=@project.version@

之后的值是这样的:

@Value("${pom.version}")
private String pomVersion;

使用这个库可以获得简单的解决方案。向清单中添加您需要的任何内容,然后按字符串查询。

 System.out.println("JAR was created by " + Manifests.read("Created-By"));

http://manifests.jcabi.com/index.html

打包的工件包含META-INF/maven/${groupId}/${artifactId}/pom。属性文件,内容如下:

#Generated by Maven
#Sun Feb 21 23:38:24 GMT 2010
version=2.5
groupId=commons-lang
artifactId=commons-lang

许多应用程序使用这个文件在运行时读取应用程序/jar版本,不需要任何设置。

上述方法的唯一问题是,该文件(目前)是在包阶段生成的,因此在测试期间不会出现(有一个Jira问题可以改变这一点,请参阅MJAR-76)。如果这对您来说是一个问题,那么Alex描述的方法就是正确的方法。

公认的答案可能是将版本号静态地放入应用程序的最佳和最稳定的方法,但实际上并没有回答最初的问题:如何从pom.xml检索工件的版本号?因此,我想提供一个替代方案,展示如何在运行时动态地做这件事:

您可以使用Maven本身。更确切地说,您可以使用Maven库。

<dependency>
  <groupId>org.apache.maven</groupId>
  <artifactId>maven-model</artifactId>
  <version>3.3.9</version>
</dependency>

然后在Java中这样做:

package de.scrum_master.app;

import org.apache.maven.model.Model;
import org.apache.maven.model.io.xpp3.MavenXpp3Reader;
import org.codehaus.plexus.util.xml.pull.XmlPullParserException;

import java.io.FileReader;
import java.io.IOException;

public class Application {
    public static void main(String[] args) throws IOException, XmlPullParserException {
        MavenXpp3Reader reader = new MavenXpp3Reader();
        Model model = reader.read(new FileReader("pom.xml"));
        System.out.println(model.getId());
        System.out.println(model.getGroupId());
        System.out.println(model.getArtifactId());
        System.out.println(model.getVersion());
    }
}

控制台日志如下:

de.scrum-master.stackoverflow:my-artifact:jar:1.0-SNAPSHOT
de.scrum-master.stackoverflow
my-artifact
1.0-SNAPSHOT

更新2017-10-31:为了回答Simon Sobisch的后续问题,我修改了这个例子:

package de.scrum_master.app;

import org.apache.maven.model.Model;
import org.apache.maven.model.io.xpp3.MavenXpp3Reader;
import org.codehaus.plexus.util.xml.pull.XmlPullParserException;

import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Application {
  public static void main(String[] args) throws IOException, XmlPullParserException {
    MavenXpp3Reader reader = new MavenXpp3Reader();
    Model model;
    if ((new File("pom.xml")).exists())
      model = reader.read(new FileReader("pom.xml"));
    else
      model = reader.read(
        new InputStreamReader(
          Application.class.getResourceAsStream(
            "/META-INF/maven/de.scrum-master.stackoverflow/aspectj-introduce-method/pom.xml"
          )
        )
      );
    System.out.println(model.getId());
    System.out.println(model.getGroupId());
    System.out.println(model.getArtifactId());
    System.out.println(model.getVersion());
  }
}