288
votes

What is the simplest way to retrieve version number from maven's pom.xml in code, i.e., programatically?

13

13 Answers

300
votes

Assuming you're using Java, you can:

  1. Create a .properties file in (most commonly) your src/main/resources directory (but in step 4 you could tell it to look elsewhere).

  2. Set the value of some property in your .properties file using the standard Maven property for project version:

    foo.bar=${project.version}
    
  3. 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).

  4. 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>
    

You can also get to other standard properties like project.name, project.description, or even arbitrary properties you put in your pom <properties>, etc. Resource filtering, combined with Maven profiles, can give you variable build behavior at build time. When you specify a profile at runtime with -PmyProfile, that can enable properties that then can show up in your build.

113
votes

The accepted answer may be the best and most stable way to get a version number into an application statically, but does not actually answer the original question: How to retrieve the artifact's version number from pom.xml? Thus, I want to offer an alternative showing how to do it dynamically during runtime:

You can use Maven itself. To be more exact, you can use a Maven library.

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

And then do something like this in Java:

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());
    }
}

The console log is as follows:

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

Update 2017-10-31: In order to answer Simon Sobisch's follow-up question I modified the example like this:

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());
  }
}
79
votes

Packaged artifacts contain a META-INF/maven/${groupId}/${artifactId}/pom.properties file which content looks like:

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

Many applications use this file to read the application/jar version at runtime, there is zero setup required.

The only problem with the above approach is that this file is (currently) generated during the package phase and will thus not be present during tests, etc (there is a Jira issue to change this, see MJAR-76). If this is an issue for you, then the approach described by Alex is the way to go.

54
votes

There is also the method described in Easy way to display your apps version number using Maven:

Add this to pom.xml

<build>
  <plugins>
    <plugin>
      <groupId>org.apache.maven.plugins</groupId>
      <artifactId>maven-jar-plugin</artifactId>
      <configuration>
        <archive>
          <manifest>
            <mainClass>test.App</mainClass>
            <addDefaultImplementationEntries>
              true
            </addDefaultImplementationEntries>
          </manifest>
        </archive>
      </configuration>
    </plugin>
  </plugins>
</build>

Then use this:

App.class.getPackage().getImplementationVersion()

I have found this method to be simpler.

23
votes

If you use mvn packaging such as jar or war, use:

getClass().getPackage().getImplementationVersion()

It reads a property "Implementation-Version" of the generated META-INF/MANIFEST.MF (that is set to the pom.xml's version) in the archive.

22
votes

To complement what @kieste has posted, which I think is the best way to have Maven build informations available in your code if you're using Spring-boot: the documentation at http://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#production-ready-application-info is very useful.

You just need to activate actuators, and add the properties you need in your application.properties or application.yml

Automatic property expansion using Maven

You can automatically expand info properties from the Maven project using resource filtering. If you use the spring-boot-starter-parent you can then refer to your Maven ‘project properties’ via @..@ placeholders, e.g.

project.artifactId=myproject
project.name=Demo
project.version=X.X.X.X
project.description=Demo project for info endpoint
[email protected]@
[email protected]@
[email protected]@
[email protected]@
7
votes

When using spring boot, this link might be useful: https://docs.spring.io/spring-boot/docs/2.3.x/reference/html/howto.html#howto-properties-and-configuration

With spring-boot-starter-parent you just need to add the following to your application config file:

# get values from pom.xml
[email protected]@

After that the value is available like this:

@Value("${pom.version}")
private String pomVersion;
6
votes

Use this Library for the ease of a simple solution. Add to the manifest whatever you need and then query by string.

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

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

6
votes

Sometimes the Maven command line is sufficient when scripting something related to the project version, e.g. for artifact retrieval via URL from a repository:

mvn help:evaluate -Dexpression=project.version -q -DforceStdout

Usage example:

VERSION=$( mvn help:evaluate -Dexpression=project.version -q -DforceStdout )
ARTIFACT_ID=$( mvn help:evaluate -Dexpression=project.artifactId -q -DforceStdout )
GROUP_ID_URL=$( mvn help:evaluate -Dexpression=project.groupId -q -DforceStdout | sed -e 's#\.#/#g' )
curl -f -S -O http://REPO-URL/mvn-repos/${GROUP_ID_URL}/${ARTIFACT_ID}/${VERSION}/${ARTIFACT_ID}-${VERSION}.jar
4
votes
    <build>
            <finalName>${project.artifactId}-${project.version}</finalName>
            <pluginManagement>
                <plugins>
                    <plugin>
                        <groupId>org.apache.maven.plugins</groupId>
                        <artifactId>maven-war-plugin</artifactId>
                        <version>3.2.2</version>
                        <configuration>
                            <failOnMissingWebXml>false</failOnMissingWebXml>
                            <archive>
                                <manifest>
                                    <addDefaultImplementationEntries>true</addDefaultImplementationEntries>
                                    <addDefaultSpecificationEntries>true</addDefaultSpecificationEntries>
                                </manifest>
                            </archive>
                        </configuration>
                    </plugin>
                 </plugins>
            </pluginManagement>
</build>

Get Version using this.getClass().getPackage().getImplementationVersion()

PS Don't forget to add:

<manifest>
    <addDefaultImplementationEntries>true</addDefaultImplementationEntries>
    <addDefaultSpecificationEntries>true</addDefaultSpecificationEntries>
</manifest>
1
votes

Step 1: If you are using Spring Boot, your pom.xml should already contain spring-boot-maven-plugin. You just need to add the following configuration.

<plugin>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-maven-plugin</artifactId>
    <executions>
        <execution>
            <id>build-info</id>
            <goals>
                <goal>build-info</goal>
            </goals>
        </execution>
    </executions>
</plugin>

It instructs the plugin to execute also build-info goal, which is not run by default. This generates build meta-data about your application, which includes artifact version, build time and more.

Step2: Accessing Build Properties with buildProperties bean. In our case we create a restResource to access to this build info in our webapp

@RestController
@RequestMapping("/api")
public class BuildInfoResource {
    @Autowired
    private BuildProperties buildProperties;

    
    @GetMapping("/build-info")
    public ResponseEntity<Map<String, Object>> getBuildInfo() {
        Map<String, String> buildInfo = new HashMap();
        buildInfo.put("appName", buildProperties.getName());
        buildInfo.put("appArtifactId", buildProperties.getArtifact());
        buildInfo.put("appVersion", buildProperties.getVersion());
        buildInfo.put("appBuildDateTime", buildProperties.getTime());
        return ResponseEntity.ok().body(buldInfo);
    }
}

I hope this will help

0
votes

With reference to ketankk's answer:

Unfortunately, adding this messed with how my application dealt with resources:

<build>
  <resources>
    <resource>
      <directory>src/main/resources</directory>
      <filtering>true</filtering>
    </resource>
  </resources>   
</build>

But using this inside maven-assemble-plugin's < manifest > tag did the trick:

<addDefaultImplementationEntries>true</addDefaultImplementationEntries>
<addDefaultSpecificationEntries>true</addDefaultSpecificationEntries>

So I was able to get version using

String version = getClass().getPackage().getImplementationVersion();
0
votes

Preface: Because I remember this often referred-to question after having answered it a few years ago, showing a dynamic version actually accessing Maven POM infos dynamically (e.g. also during tests), today I found a similar question which involved accessing module A's Maven info from another module B.

I thought about it for a moment and spontaneously had the idea to use a special annotation, applying it to a package declaration in package-info.java. I also created a multi-module example project on GitHub. I do not want to repeat the whole answer, so please see solution B in this answer. The Maven setup involves Templating Maven Plugin, but could also be solved in a more verbose way using a combination of resource filtering and adding generated sources directory to the build via Build Helper Maven. I wanted to avoid that, so I simply used Templating Maven.