Need help with objenesis?
Click the “chat” button below for chat support from the developer who created it, or find similar developers for support.

About the developer

486 Stars 82 Forks Apache License 2.0 692 Commits 9 Opened issues


Okay, it's pretty easy to instantiate objects in Java through standard reflection. However there are many cases where you need to go beyond what reflection provides. For example, if there's no public constructor, you want to bypass the constructor code, or set final fields. There are numerous clever (but fiddly) approaches to getting around this and this library provides a simple way to get at them. You will find the official site here.

Services available


Need anything else?

Contributors list


Objenesis is a library dedicated to bypass the constructor when creating an object. On any JVM there is.

You can find the website and user documentation at

Developer information

Project status

Build Status Maven Central

Environment setup

I'm using: - Maven 3.6.3 - IntelliJ Ultimate 2021.1 (thanks to JetBrains for the license) (it should also work with Eclipse)

To configure your local workspace: - Import the Maven parent project to Eclipse or IntelliJ - Import the Eclipse formatting file

(usable in Eclipse or IntelliJ)

To build with Maven

There are two different levels of build.

Build without any active profile

It is a basic compilation of the application.

mvn install

Full build

This build will create the source and javadoc jars and run spotbugs.

mvn install -Pfull

To run special builds

Run the Android TCK

  • Install the Android SDK (
    brew cask install android-sdk
  • Install
    using the sdkmanager (
    sdkmanager "platform-tools" "build-tools"
  • Add an
    to target the Android SDK (
    export ANDROID_HOME=$(realpath $(echo "$(dirname $(readlink $(which sdkmanager)))/../.."))
  • Configure a device (real or simulated) and launch it (use API 26, after that it asks for a signature, that isn't supported yet)
  • Activate the debug mode if it's a real device
  • mvn package -Pandroid

Run the benchmarks

mvn package -Pbenchmark
cd benchmark

Generate the website

mvn package -Pwebsite

To update the versions

  • mvn versions:set -DnewVersion=X.Y -Pall
  • mvn versions:commit -Pall
    if everything is ok,
    mvn versions:revert -Pall

Configure to deploy to the Sonatype maven repository

  • You will first need to add something like this to your settings.xml
  • Then follow the instructions from the site below to create your key to sign the deployed items

To check dependencies and plugins versions

mvn versions:display-dependency-updates versions:display-plugin-updates -Pall

To upgrade the Maven wrapper

mvn -N io.takari:maven:wrapper -Dmaven=3.6.3

To update the license

mvn validate license:format -Pall

To release

  • Add the release notes in
    You use this code to generate it
# Get the milestone matching the version
version=(mvn help:evaluate -Dexpression=project.version -q -DforceStdout | cut -d'-' -f1)
milestone=$(curl -s "" | jq ".[] | select(.title==\"$version\") | .number")
echo "

Version $version ($(date '+%Y-%m-%d'))

" echo echo "
    " curl -s "${milestone}&state=all" | jq -r '.[] | "
  • " + .title + " (#" + (.number|tostring) + ")
  • "' echo "
  • Launch an Android device (virtual or physical)
  • Launch
  • Answer the questions (normally, just acknowledge the proposed default)
  • Follow the instructions

If something fails, and you need to rollback a bit, the following commands might help:

mvn release:rollback -Pall
git tag -d $version
git push origin :refs/tags/$version
git reset --hard HEAD~2

If you find something went wrong you can drop the staging repository with

mvn nexus-staging:drop

Deploy the website

  • Make sure the pom is at the version you want to release
  • Launch

We use cookies. If you continue to browse the site, you agree to the use of cookies. For more information on our use of cookies please see our Privacy Policy.