Java has been around for nearly three decades, and it’s still one of the most-used programming languages in the world. But while the language itself keeps evolving, so does the ecosystem around it. Java has many technologies & tools like build tools, debuggers, IDEs and testing frameworks and to keep a track of them can be difficult.
So in this post, we are going to give you a list of the tools Java developers actually use (we use them too).
Let's dive in.
Build Tools
The Java ecosystem has two main players here , Maven and Gradle, and while both get the job done, each has its strengths.
Maven
Maven has been around for years and is still a very preferable choice by developers. Apache Maven is a build automation and project management tool. It simplifies the process of managing a project's build, dependencies, documentation, and other tasks related to project lifecycle.
Why developers still use it:
Massive community support
Tons of existing plugins
Stable and predictable builds
If you’re working on legacy projects or large enterprise systems, chances are Maven is already in play.
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
Gradle
Gradle also has been around for more than a decade so it’s not newer but it is younger than Maven. Gradle is a modern build automation tool used for developing applications, primarily in Java, Kotlin, Groovy, and Android. It's known for being flexible, high-performance, and developer-friendly, and it has largely become the standard for Android development.
Why developers love it:
Faster builds, especially with large codebases
Easier to customize
Cleaner syntax (especially with Kotlin DSL)
dependencies {
implementation("org.springframework.boot:spring-boot-starter-web")
}
Quick Tip:
If you’re starting a new project and want simplicity, go with Gradle. If you’re joining an older codebase or need strict build reproducibility, Maven is still a solid bet.
IDEs & Code Editors
Every developer has strong opinions about their IDE. These editors is where you debug, refactor, test, and stay in flow. It's obvious that they are important. In Java there are few editors that consistently rise to the top.
1. IntelliJ IDEA
This is the favorite for a reason. IntelliJ feels like it is helping you write code, not just letting you type. It reads your mind sometimes. You start writing a method and it already knows what you want. It catches errors before you run anything. It even suggests cleaner ways to do the same thing.
Where it really helps:
It handles refactoring so well that you start refactoring more often, which makes your code better.
It understands frameworks like Spring. You get smart hints and quick fixes when something is off.
You can work with Git, Docker, and databases without ever leaving the editor.
The Community Edition is free and good enough for most Java work. But if you use Spring Boot, web development tools, or anything enterprise level, the paid version unlocks even more useful features.
2. Eclipse
Eclipse has been around forever, and while it may not feel as modern, it still gets the job done. Some developers even prefer it because it gives you more control.
Why it still works:
You can customize almost everything. The plugin system is deep and flexible.
It is good with large projects and enterprise codebases that are too heavy for smaller editors.
It supports Java EE and other old school but important stacks very well.
It takes more effort to set up, but some developers like that. Once you configure it your way, it feels solid and familiar.
3. VS Code
This one is a bit unexpected. VS Code is not a Java IDE out of the box, but with the right extensions, it turns into a lightweight Java development environment that works surprisingly well.
Why people love it:
It opens fast and feels snappy, even on older machines.
If you work with more than one language like JavaScript or Python, it is nice to have one editor for everything.
The Java extension pack adds all the basics: auto-complete, debugging, Maven support, and even test runners.
It may not be as deep as IntelliJ or Eclipse, but it is fast, clean, and does the job for a lot of modern projects.
Bonus Picks
If you are just starting out, you might also hear about NetBeans. It is simple and has good Java support right from the start. Tools like BlueJ or DrJava are also great for beginners, especially in schools or intro courses.
Testing Tools
Writing code is one thing. Making sure it works the way you expect is another. Testing is not just for catching bugs. It also helps you avoid breaking things when your code changes later. Java has some of the best testing tools out there, and they keep getting better.
Let us look at the most useful ones Java developers use to test their code with confidence.
JUnit
The most popular testing library for Java is called JUnit. The majority of Java projects use it for unit testing, and it has been around for years.
Why developers love it:
It is simple to set up and easy to read
You can run tests directly inside your IDE
Works well with build tools like Maven and Gradle
JUnit is often the first testing tool you learn in Java, and it is powerful enough to use throughout your career. The newer version, JUnit 5, adds more flexibility and cleaner syntax.
Mockito
Writing tests for code that depends on other classes can be tricky. That is where Mockito helps. It lets you create fake versions of objects, so you can test your logic without needing real data or full systems running.
Where it helps most:
When testing service or controller classes that call other layers
When you want to check how your code behaves, not what it returns
When working with external APIs, databases, or slow resources
Mockito works really well with JUnit, and you will often use them together in the same test file.
TestNG
TestNG is like JUnit with more features. It supports things like parallel test execution and better control over test groups and configurations. Some teams use it for larger or more complex testing needs.
You might like TestNG if:
You are testing large systems with many moving parts
You need detailed setup and teardown steps
You want to run different sets of tests under different conditions
It is a bit more advanced than JUnit but worth exploring if you need more flexibility.
AssertJ
Tests are readable because of assertions. With AssertJ, you can create tests that read like plain English rather than just "true or false."
For example:
assertThat(user.getName()).startsWith("J").endsWith("n");
This makes your tests more descriptive and easier to understand later. AssertJ works smoothly with JUnit and Mockito.
In Short
JUnit is the foundation of most Java testing setups.
Mockito makes it easier to test classes in isolation.
TestNG is useful for more complex or structured test suites.
AssertJ makes your tests easier to read and maintain.
Tools for Java Performance Optimization
the thing with performance is that you do not always notice problems until your app is under pressure. A loop that looks fine in testing might freeze under real traffic. A small memory leak might grow over time and crash the whole thing at the worst moment.
That is why Java performance tools exist. They help you see what is really happening under the hood and fix it before things go wrong.
JVisualVM
VisualVM is like a live dashboard for your Java application. It comes with the Java Development Kit, so you probably already have it. You just need to start using it.
With this tool, you can watch your app while it runs. You can see how much memory it is using, what the threads are doing, and whether the CPU is working too hard. If your app is acting weird, JVisualVM lets you take a memory snapshot and explore what is filling it up. This helps you catch memory leaks and slow operations early.
It is lightweight, visual, and surprisingly powerful for something that is built in.
Java Mission Control
JVisualVM functions similarly to a Java application's performance dashboard. It lets you see what's happening while your app is operating. Moreover, You don't need to install anything else because it comes with the Java Development Kit.
This tool is perfect for catching problems early. You can open it while testing your app and watch how memory is being used, how many threads are running, and whether the CPU is working too hard.
What you can do with it:
Track memory usage as your app runs
Monitor how much CPU each thread is using
Take snapshots of the memory heap to find leaks
Watch thread activity to detect blocking or deadlocks
JVisualVM gives you a live view of your app’s health. You can spot slowdowns before they turn into real problems.
Java Mission Control
Java Mission Control works together with Java Flight Recorder to give you a deep look into your app’s behavior over time. Instead of watching things live, you can record a session and explore it later in detail.
What you can do with it:
Record how long different parts of your code take to run
Find patterns in garbage collection that might slow things down
Analyze what threads were doing during slow periods
Explore what changed when the app suddenly started using more CPU or memory
It gives you a detailed report of what your app is doing behind the scenes, which helps a lot when you are debugging strange slowdowns.
YourKit
YourKit is a professional performance profiler that goes much deeper than the free tools. It is often used in large projects and enterprise environments where performance issues can cost time and money.
What makes YourKit powerful is how detailed it gets. It shows you not just that something is slow, but exactly where and why. You can follow memory leaks right to the line of code that caused them. You can see which methods are taking up most of the CPU, and which objects are being created too often.
What you can do with it:
Profile every part of your app’s execution to find slow or expensive code
Detect memory leaks that would be hard to catch by hand
Connect to running applications without restarting them, which is great for production systems
Work with data offline so you can analyze performance after something goes wrong
VisualVM Plugins
VisualVM becomes even more useful when you add plugins. These small add-ons let you customize the tool based on what you are building and what you need to monitor.
For example, if you are working with Spring, there are plugins that let you track how your Spring beans behave. If your app is running on another machine, you can install a plugin that lets you monitor it remotely. And if you want to track something unique to your app, you can even write your own plugin.
What you can do with it:
Add support for specific frameworks like Spring or Tomcat
Enable remote monitoring so you can watch apps running on other servers
Track custom metrics that matter to your business or application logic
Final Thoughts
If you are just getting started, begin with the essentials. Learn your IDE well, get comfortable with basic debugging, and explore performance tools like JVisualVM. As your project grows, your toolbox should grow with it. The right tools do not just make development easier but they do make your code stronger.
And if all this feels overwhelming, that is okay too. Sometimes, the best move is to bring in someone who knows the landscape. If your project needs expert hands, it might be time to hire Java developer who already knows how to use these tools well and can help your team move faster with fewer roadblocks.
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