Javaagent Gradle Plugin

Gradle plugin for easy configuration of Java Agents.

Supports:

• Java application running/testing
• Java library testing
• Android application testing
• Android library testing

The problem

From the perspective of the recent improvements in Java runtime security, Java Agents are seen as a possible attack vector. Hence, the implicit attachment of Java Agent is currently discouraged, and in future might get forbidden. At the current moment, developers will see a runtime warning similar to this if a Java Agent is attached dynamically:

Mockito is currently self-attaching to enable the inline-mock-maker. This will no longer work in future releases of the JDK. 
Please add Mockito as an agent to your build as described in Mockito's documentation: https://javadoc.io/doc/org.mockito/mockito-core/latest/org.mockito/org/mockito/Mockito.html#0.3

WARNING: A Java agent has been loaded dynamically (C:\.gradle\caches\modules-2\files-2.1\net.bytebuddy\byte-buddy-agent\1.17.7\fbf3d6d649ed37fc9e9c59480a05be0a26e3c2da\byte-buddy-agent-1.17.7.jar)
WARNING: If a serviceability tool is in use, please run with -XX:+EnableDynamicAgentLoading to hide this warning
WARNING: If a serviceability tool is not in use, please run with -Djdk.instrument.traceUsage for more information
WARNING: Dynamic loading of agents will be disallowed by default in a future release

The solution

The solution is to explicitly specify Java Agent(s) using -javaagent:xxxx command line which exist for this very purpose.

Javaagent Gradle Plugin allows you to easily specify which configurations should have which Java Agent attached. For example, this Mockito test is configured to use Mockito's own Java Agent:

dependencies {
    testImplementation(platform("org.mockito:mockito-bom:$mokito_version"))
    testImplementation("org.mockito:mockito-core")
    testJavaagent("org.mockito:mockito-core")
    ...
}

Setup

Configure the plugin in your settigs.gradle.kts:

pluginManagement {
    repositories {
        gradlePluginPortal()
    }

    plugins {
        id("io.github.neboskreb.javaagent").version("1.2.7")
    }
}

Apply the plugin in your build.gradle.kts and specify the configuration(s) and agent(s):

plugins {
    id("io.github.neboskreb.javaagent")
}

dependencies {
    // Attaching the Byte Buddy to the app:
    javaagent("net.bytebuddy:byte-buddy-agent:1.17.7")
    
    // Letting Mockito to use its agent for dynamic mocking:
    testImplementation(platform("org.mockito:mockito-bom:5.18.0"))
    testImplementation("org.mockito:mockito-core")
    testJavaagent("org.mockito:mockito-core")
}

Android Support

Javaagent Gradle Plugin supports both Application and Library type of Android project. JUnit versions 5 and 6 are supported.

Simply apply plugin io.github.neboskreb.javaagent and add testJavaagent to your JUnit test dependencies:

plugins {
    id("com.android.application")
    id("io.github.neboskreb.javaagent")
}

dependencies {
    testImplementation(platform("org.mockito:mockito-bom:5.18.0"))
    testImplementation("org.mockito:mockito-core")
    testJavaagent("org.mockito:mockito-core")
    
    // Note that Android tests use Mockito-Android which does not require java agent
    androidTestImplementation("org.mockito:mockito-android:5.21.0")
    androidTestImplementation("org.mockito:mockito-junit-jupiter:5.21.0")
}

Note

You don't need to add androidTestJavaagent.

Examples

Feel free to load submodule examples with IntelliJ or Android Studio and poke around.

Contributions

Pull requests are welcome! If you plan to open one, please first create an issue where you describe the problem/gap your contribution closes, and tag the keeper(s) of this repo so they could get back to you with help.

License

Copyright 2025 John Y. Pazekha

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

See also the full License text.