Support for JDK 21 String Templates/Template processors (STR, RAW)

[jackytank]

Issue

In my VSCode, I had installed the extension Language Support for Java(TM) by Red Hat pre-release version, and my Spring Boot project is using Java 21 so in one of my business logic code I want to use String Templates to concatenate Strings together

in the above image in VSCode it show syntax error when using Template processor STR.

Description

Here is my PC environment info:

• Java: Temurin-21.0.5+11 (build 21.0.5+11-LTS)

• Maven: Apache Maven 3.9.9

• PC:

• VSCode extension version
  Language Support for Java(TM) by Red Hat v1.39.2025011708 (pre-release)

[rgrunber]

See eclipse-jdt/eclipse.jdt.core#2353, https://bugs.openjdk.org/browse/JDK-8329949 . String Templates were a preview feature in Java 21, 22, and it was removed in Java 23.

Each version of vscode-java can only support the latest set of preview feature. For example, if we support the language preview features for Java 23 (if any), while you can certainly set your target to Java 21, or even 22, you can't also enabled preview features from those releases. Only from the latest one. Normally that would be fine because the feature would be finalized in a later release, but in this case it has been removed, so the result is it's no longer supported.

If you really wanted to work with string templates, you could try vscode-java 1.34.0 as that was the last version to still support Java 22 preview features, which would have included String Templates.

[jackytank]

See eclipse-jdt/eclipse.jdt.core#2353, https://bugs.openjdk.org/browse/JDK-8329949 . String Templates were a preview feature in Java 21, 22, and it was removed in Java 23.

Each version of vscode-java can only support the latest set of preview feature. For example, if we support the language preview features for Java 23 (if any), while you can certainly set your target to Java 21, or even 22, you can't also enabled preview features from those releases. Only from the latest one. Normally that would be fine because the feature would be finalized in a later release, but in this case it has been removed, so the result is it's no longer supported.

If you really wanted to work with string templates, you could try vscode-java 1.34.0 as that was the last version to still support Java 22 preview features, which would have included String Templates.

ohh sad to hear Java removed it, hope it will comeback soon