Red Hat has released version 1.0 of Language support for Java on Visual Studio Code with new features that include: support for Java 17; improvement in performance by deferring some computations based on new features of the LSP specification; tuning the various JVM options; optimization in the responsiveness of the language server; and the ability to display the Type hierarchy. The source lookup feature has been improved and now supports unmanaged projects, without Maven or Gradle, and is able to display sources of any library available on Maven central. This release also contains new code actions, to increase developer productivity, for example, to add a missing method. Lastly, support for Gradle files written in Kotlin (.kts) was introduced.
The Language support for Java extension is activated when a Java file is opened. Maven, Gradle and standalone Java projects are supported, and the build tool is automatically detected. Common IDE features are supported, such as code completion, refactoring, compile errors, Javadoc, code navigation, code formatting, call hierarchies and type hierarchies.
The Language support for Java extension may be downloaded separately or via the Extension Pack for Java which also contains the Language Support for Java plugin together with plugins for debugging, running tests, Maven, project manager and Intellicode. VSCode supports various Java frameworks and tools with separate plugins for Spring Boot, Microprofile, Quarkus, Docker, Kubernetes, Tomcat, Jetty, SonarLint and Checkstyle.
JDK 11 or higher is required to run the extension and can be configured with the java.home field in the VS Code settings. If not specified, the extension tries to detect the JDK in the following order: JDK_HOME environment variable, JAVA_HOME environment variable, or via the system path. The user settings may be used to compile the application against multiple configured JDKs:
"java.configuration.runtimes": [
{
"name": "JavaSE-1.8",
"path": "/path/to/jdk-8",
},
{
"name": "JavaSE-17",
"path": "/path/to/jdk-17",
"default": true
},
]
Language support for Java uses the Eclipse JDT Language Server, which in turn makes use of Eclipse JDT, M2Eclipse and Buildship.
Red Hat introduced version 0.0.1 of the Language support for Java Plugin for VSCode on September 12th, 2016. Since then, Red Hat has released new versions about once or twice a month, and after slightly more than five years, version 1.0.0 was released on October 19th, 2021.
Fred Bricon, principal software engineer at Red Hat, explains that they opted to name the release 1.0 as it had all the features they originally wanted. Nonetheless, Red Hat and other organizations are still working on improving the support for Java in VSCode. For instance, Microsoft, who recently announced the release of the extension, is working on the fact that Eclipse metadata files are created in the folder, which is not always desirable.
Plans outlined in the future roadmap include embedding a Java runtime to make it easier to get started, improving the startup and general performance, extending the code actions and auto-completion, and improving the configuration of code formatting and compiler errors/warnings.