Execute python scripts in maven projects

Jan 27, 2025

Introduction

This post demonstrates how to execute Python scripts in Maven projects. We will execute a Python script during the build process and generate a file to be packaged in the target JAR.

Environments

Maven 3.x
Python 2.7

The exec-maven-plugin plugin

The exec-maven-plugin allows you to execute scripts during the Maven build lifecycle. There are two goals of this plugin:

exec:exec: Executes programs and Java programs in a separate process.
exec:java: Executes Java programs in the same VM.

We will use the exec:exec goal to execute a Python script.

The pom.xml

<build>
    <plugins>
        <plugin>
            <groupId>org.codehaus.mojo</groupId>
            <artifactId>exec-maven-plugin</artifactId>
            <version>1.6.0</version>
            <executions>
                <execution>
                    <configuration>
                        <executable>python</executable>
                        <workingDirectory>src/main/resources/</workingDirectory>
                        <arguments>
                            <argument>my.py</argument>
                        </arguments>
                    </configuration>
                    <id>python_build</id>
                    <phase>generate-resources</phase>
                    <goals>
                        <goal>exec</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

Explanation

We add a build plugin named exec-maven-plugin to the Maven project.
The plugin is configured to run a Python script named my.py in the src/main/resources directory.
The plugin will be executed during the generate-resources phase of the Maven build process.

The Python script

Create a new Python script named my.py in the src/main/resources directory of the project with the following content:

# coding=UTF-8
import os,io
cur_path = os.getcwd() #should be the src/main/resources
with io.open(cur_path+"/tempfile", mode='w') as the_file:
    the_file.write(u'hello maven')

What the script does:

Retrieves the current path, which should be src/main/resources.
Uses the io.open function to create a new file named tempfile.
Writes the string hello maven into the file.

Run the script

Execute the following command to run the script:

mvn compile

You should see output similar to this:

[INFO] Building test-maven-python 1.0-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- exec-maven-plugin:1.6.0:exec (python-build) @ test-maven-python ---
[INFO]
[INFO] --- maven-resources-plugin:2.5:resources (default-resources) @ test-maven-python ---
[debug] execute contextualize

Check the file and its content:

➜  resources git:(master) ✗ ll tempfile
-rw-r--r--  1 zzz  staff    11B Apr 28 22:19 tempfile
➜  resources git:(master) ✗ cat tempfile
hello maven%

Summary

The exec-maven-plugin allows you to execute Java or system scripts during the Maven build lifecycle. In this demo, we successfully executed a Python script within a Maven project, demonstrating how to integrate Python scripts into your Maven build process.

Final Words + More Resources

My intention with this article was to help others who might be considering solving such a problem. So I hope that’s been the case here. If you still have any questions, don’t hesitate to ask me by email: Email me

Here are also the most important links from this article along with some further resources that will help you in this scope:

👨‍💻 exec-maven-plugin

Oh, and if you found these resources useful, don’t forget to support me by starring the repo on GitHub!