@codemirror/lang-java

What is @codemirror/lang-java?

@codemirror/lang-java is a language support package for the CodeMirror 6 code editor, specifically designed to provide syntax highlighting, code folding, and other language-specific features for Java programming.

What are @codemirror/lang-java's main functionalities?

Syntax Highlighting

This code sets up a CodeMirror editor instance with Java syntax highlighting. The `java` function from `@codemirror/lang-java` is used to enable Java language support.

import { java } from '@codemirror/lang-java';
import { EditorState } from '@codemirror/state';
import { EditorView, basicSetup } from '@codemirror/basic-setup';

const state = EditorState.create({
  doc: 'public class HelloWorld {\n  public static void main(String[] args) {\n    System.out.println("Hello, World!");\n  }\n}',
  extensions: [basicSetup, java()]
});

const view = new EditorView({
  state,
  parent: document.body
});

Code Folding

This code demonstrates how to set up code folding in a CodeMirror editor with Java language support. The `foldGutter` extension is used alongside the `java` language support.

import { java } from '@codemirror/lang-java';
import { foldGutter } from '@codemirror/fold';
import { EditorState } from '@codemirror/state';
import { EditorView, basicSetup } from '@codemirror/basic-setup';

const state = EditorState.create({
  doc: 'public class HelloWorld {\n  public static void main(String[] args) {\n    System.out.println("Hello, World!");\n  }\n}',
  extensions: [basicSetup, java(), foldGutter()]
});

const view = new EditorView({
  state,
  parent: document.body
});

Autocompletion

This code sets up autocompletion in a CodeMirror editor with Java language support. The `autocompletion` extension is used alongside the `java` language support.

import { java } from '@codemirror/lang-java';
import { autocompletion } from '@codemirror/autocomplete';
import { EditorState } from '@codemirror/state';
import { EditorView, basicSetup } from '@codemirror/basic-setup';

const state = EditorState.create({
  doc: 'public class HelloWorld {\n  public static void main(String[] args) {\n    System.out.println("Hello, World!");\n  }\n}',
  extensions: [basicSetup, java(), autocompletion()]
});

const view = new EditorView({
  state,
  parent: document.body
});

Other packages similar to @codemirror/lang-java

@codemirror/lang-javascript

@codemirror/lang-javascript provides similar functionalities for JavaScript, including syntax highlighting, code folding, and autocompletion. It is tailored for JavaScript and TypeScript, making it ideal for web development projects.

monaco-editor

Monaco Editor is the code editor that powers Visual Studio Code. It supports a wide range of languages, including Java, and offers features like syntax highlighting, code folding, and autocompletion. It is more heavyweight compared to CodeMirror but provides a rich set of features.

ace-builds

Ace is a standalone code editor written in JavaScript. It supports syntax highlighting, code folding, and autocompletion for multiple languages, including Java. Ace is known for its performance and ease of integration into web applications.

README

@codemirror/lang-java

[ WEBSITE | ISSUES | FORUM | CHANGELOG ]

This package implements Java language support for the CodeMirror code editor.

The project page has more information, a number of examples and the documentation.

This code is released under an MIT license.

We aim to be an inclusive, welcoming community. To make that explicit, we have a code of conduct that applies to communication around the project.

Usage

import {EditorView, basicSetup} from "codemirror"
import {java} from "@codemirror/lang-java"

const view = new EditorView({
  parent: document.body,
  doc: `public static void main(String[] args) {}`,
  extensions: [basicSetup, java()]
})

API Reference

java() → LanguageSupport

Java language support.

javaLanguage: LRLanguage

A language provider based on the Lezer Java parser, extended with highlighting and indentation information.

Changelog

6.0.2 (2025-06-19)

Bug fixes

Add a .d.cts file to make TypeScript happy.