Java offers a wide range of automation testing tools that are widely used for testing Java applications as well as applications built with other technologies.

Here are some popular Java automation testing tools:

1. JUnit: JUnit is a widely used unit testing framework for Java. It provides a simple and straightforward API for writing and executing unit tests. JUnit allows you to define test cases, setup and teardown methods, assertions, and test suites. It integrates well with build automation tools and IDEs.

2. TestNG: TestNG is a testing framework that extends JUnit and offers additional features. It supports various testing types, including unit testing, functional testing, and integration testing. TestNG provides advanced features such as parameterized tests, data-driven testing, test dependencies, parallel test execution, and test configuration through XML files.

3. Selenium: Selenium is a popular automation testing framework for web applications. It provides a suite of tools and libraries for browser automation, allowing you to simulate user interactions, perform actions, and validate web application behavior. Selenium supports multiple programming languages, including Java, and integrates well with testing frameworks like JUnit and TestNG.

4. Cucumber: Cucumber is a behavior-driven development (BDD) testing framework that promotes collaboration between stakeholders and developers. It allows you to write test scenarios in a human-readable format using Gherkin language. Cucumber supports Java and integrates with testing frameworks like JUnit and TestNG. It enables the execution of automated acceptance tests and facilitates clear communication between business stakeholders and technical team members.

5. Appium: Appium is an open-source automation framework for mobile applications. It allows you to automate testing of native, hybrid, and mobile web applications on Android and iOS platforms. Appium provides APIs for interacting with mobile elements, simulating gestures, and validating mobile app behavior. It supports multiple programming languages, including Java, and integrates with testing frameworks like JUnit and TestNG.

6. JMeter: Apache JMeter is a popular performance testing tool. It enables load testing, stress testing, and measuring the performance of web applications. JMeter allows you to simulate high user loads, measure response times, monitor system resources, and generate performance reports. It supports scripting and can be integrated with Java-based testing frameworks.

These are just a few examples of Java automation testing tools. Depending on your specific requirements, you may explore other tools and frameworks like Mockito for mocking dependencies, RestAssured for API testing, or WireMock for simulating HTTP services. The choice of tool depends on factors such as the type of application, testing objectives, project requirements, and personal preferences.