[BUG] Claude Code execution environment uses JDK 17, blocking compilation for Java 21+ projects

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Claude Code's shell environment only has JDK 17 available (java -version returns 17.0.12). This means any project targeting Java 21, 25 (LTS), or newer will fail to compile when Claude attempts to run Gradle or Maven build commands.

What Should Happen?

Claude Code's environment should ship with a recent JDK (ideally the current LTS — Java 25) so it can compile, test, and run Java projects without requiring the user to fall back to their local terminal.

Error Messages/Logs

Build fails. Claude cannot verify compilation correctness, catch type errors, or run tests on any project targeting Java > 17.

Steps to Reproduce

1. Open a Java project with sourceCompatibility = JavaVersion.VERSION_25 (or 21+)
2. Ask Claude to compile: ./gradlew build -x test
3. Build fails with: error: invalid source release: 25

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.140

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

IntelliJ IDEA terminal

Additional Information

Environment:

• OS: Windows 11
• Claude Code version: 2.1.140
• Project: Spring Boot 3.3 / Gradle 9.1.0, targeting Java 25