Java in Visual Studio Code

Java in Visual Studio Code

Support for Java in Visual Studio Code is provided through a wide range of extensions. Combined with the power of core VS Code, these extensions give you a lightweight and performant code editor that also supports many of the most common Java development techniques.

This article will give you an overview of different capabilities of Visual Studio Code for Java developers. For a quick walkthrough of editing, running, and debugging a Java program with Visual Studio Code, use the button below.

Java Getting Started Tutorial

Overview

VS Code provides essential language features such as code completion, refactoring, linting, formatting, and code snippets along with convenient debugging and unit test support. VS Code also integrates with tooling and frameworks such as Maven, Tomcat, Jetty, and Spring Boot. Leveraging the power of Visual Studio Code, Java developers get an excellent tool for both quick code editing and also the full debugging and testing cycle. It’s a great choice for your Java work if you’re looking for a tool which:

Is fast, lightweight, free, and open source.
Supports many other languages, not just Java.
Helps start your Java journey without installing and learning a complex IDE.
Provides great microservices support including popular frameworks, container tooling, and cloud integration.
Offers team-based collaboration features such as Visual Studio Live Share.
Improves your productivity through IntelliSense and other code-aware editing features.

Install Visual Studio Code for Java

VS Code is a fast editor and ships with great editing features. Before you begin, you must have the Java SE Development Kit (JDK) on your local environment. Visual Studio Code works with all major Java versions from various vendors up to 14.

To help you get started quickly, we created a special Installer of Visual Studio Code for Java developers. The package can be used as a clean install or an update for an existing development environment to add Java or Visual Studio Code. Once downloaded and opened, it automatically detects if you have the fundamental components in your local development environment, including the JDK, Visual Studio Code, and essential Java extensions. During install, it downloads the stable versions of those tools from trusted online sources and installs them on your system.

Download Visual Studio Code Java Pack Installer

Note: The Java Pack Installer is currently only available for Windows. For other OS, don’t worry. Everything still works, you just have to install those components (JDK, VS Code and Java extensions) individually. We’re working on the macOS version, please stay tuned. This documentation will tell you which extensions to install.

Alternatively, you can also add Java language support to VS Code by installing the popular Java extensions by yourself.

Download VS Code - If you haven’t downloaded VS Code yet, quickly install for your platform (Windows, macOS, Linux).

To help set up Java on VS Code, there is a Java Extension Pack, which contains the most popular extensions for most Java developers:

Install the Java Extension Pack

There are also other popular Java extensions you can pick for your own needs, including:

Thanks to the great Java community around VS Code, the list doesn’t end there. You can search for more Java extensions easily within VS Code:

Go to the Extensions view (kb(workbench.view.extensions)).
Filter the extensions list by typing “java”.

This document describes some of the key features included in those Java extensions.

Getting started

NOTE: If you are using VS Code on Windows and want to take advantage of the Windows Subsystem for Linux, see Developing in WSL.

For developers new to Java or new to VS Code, we provide a Getting Started experience. Once you’ve installed the Java Extension Pack, you can open the Getting Started experience from within VS Code with the Java: Getting Started command from the Command Palette. Open the Command Palette (kb(workbench.action.showCommands)) and type “Java: Getting Started”.

Standalone Java source files

You can use VS Code to open any Java source file(s). As a lightweight editor, VS Code can provide you features such as syntax and semantic highlighting and error detection, code navigation, outline as well as Javadoc features with its Syntax Server immediately without resolving the project. Syntax mode makes VS Code an ideal tool for reading and learning any Java code base.

At the same time, a more powerful Java language server will be started in backend to resolve and index your whole project to provide you more advanced features such as code completion. You can switch between Syntax mode and full language server as you need.

Java project support

There are three things you must understand to work with Java in VS Code:

How does VS Code handle Workspaces?
How does VS Code handle Java?
How does VS Code handle Workspaces that contain Java?

VS Code Workspaces

In Visual Studio Code, a “Workspace” means a collection of one or more filesystem folders (and their children) and all of the VS Code configurations that take effect when that “Workspace” is open in VS Code. There are two kinds of “Workspaces” in VS Code, “folder workspaces” and “multi-root workspaces”.

A “folder workspace” is presented by VS Code when you open a filesystem folder (directory) in VS Code.

A “multi-root workspace” can refer to multiple folders (directories) from disparate parts of the file system and VS Code displays the contents of the folder(s) of the workspace together in the File Explorer. To learn more, see Multi-root Workspaces.

Java project in VS Code

In contrast to IDEs such as IntelliJ IDEA, NetBeans, or Eclipse, the concept of a “Java project” is provided entirely by extensions, and is not a core concept in the base VS Code. When working with “Java projects” in VS Code, you must have the necessary extensions installed to work with those project files.

For example, Maven, Eclipse, and Gradle Java projects are supported through Language Support for Java(TM) by Red Hat, by utilizing M2Eclipse, which provides Maven support, and Buildship, which provides Gradle support through the Eclipse JDT Language Server.

With Maven for Java, you can generate projects from Maven Archetypes, browse through all the Maven projects within your workspace, and execute Maven goals easily from an embedded explorer. Projects can also be created and managed with the Java Dependency Viewer extension.

Visual Studio Code also supports working with standalone Java files outside of a Java project, described in the Java Tutorial with VS Code.

VS Code Workspaces that contain Java project

Assuming the necessary Java extensions are installed, opening a VS Code workspace that contains Java artifacts will cause those extensions to understand those artifacts and present options for working with them.

More details about Java project support can be found in Java Project Management in Visual Studio Code and Build Tools.

Editing

Code Navigation

Java in Visual Studio Code also supports source code navigation features such as search for symbol, Peek Definition, and Go to Definition. The Spring Boot Tools extension provides enhanced navigation and code completion support for Spring Boot projects.

One of the key advantages of VS Code is speed. When you open your Java source file or folder, within a few seconds, with the help of Syntax Mode, you will be able to navigate your code base with Outline view as well as commands such as Go to Definition and Go to Reference. This is especially useful when you open a project for the first time.

Code Completion

IntelliSense is a general term for language features, including intelligent code completion (in-context method and variable suggestions) across all your files and for built-in and third-party modules. VS Code supports code completion and IntelliSense for Java through Language Support for Java(TM) by Red Hat. It also provides AI-assisted IntelliSense called IntelliCode by putting what you’re most likely to use at the top of your completion list.

See also in Java Code Navigation and Editing. VS Code also supports a range of Refactoring and Linting features.

Debugging

Debugger for Java is a lightweight Java Debugger based on Java Debug Server. It works with Language Support for Java by Red Hat to allow users to debug Java code within Visual Studio Code.

Starting a debugging session is easy, click on the Run|Debug button available at the CodeLens of your main() function, or press kb(workbench.action.debug.start). The debugger will automatically generate the proper configuration for you.

Although it’s lightweight, the Java debugger supports advanced features such as expression evaluation, conditional breakpoints, and hot code replacement. For more debugging related information, visit Java Debugging.

Testing

With the support from the Java Test Runner extension, you can easily run, debug, and manage your JUnit and TestNG test cases.

For more about testing, read Testing Java.

Spring Boot, Tomcat, and Jetty

To further improve your Java productivity in VS Code, there are extensions for most popular frameworks and tools such as Spring Boot, Tomcat, and Jetty created by the community.

The Tomcat extension includes an explorer to easily navigate and manage your Tomcat servers. You can create, start, debug, stop, and rename your Tomcat server with the extension.

See Application Servers to learn more about support for Tomcat and Jetty as well as other application servers with VS Code.

Spring Boot support is provided by Pivotal. There are also Spring Initializr Java Support and Spring Boot Dashboard extensions available from Microsoft to further improve your experience with Spring Boot in Visual Studio Code.

See Spring Boot with VS Code to learn more about Spring Boot support with VS Code.

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