RedHat OpenJDK might be a bit more popular than Microsoft Visual Studio. We know about 1 link to it since March 2021 and only 1 link to Microsoft Visual Studio. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
While the editor seems to old fashioned there isn't anything particularly wrong in using it for learning. Alternatively you can propose to your teacher about https://visualstudio.microsoft.com/vs/express/ . IMO editor is not a big factor when we are talking about high school learning. Source: almost 4 years ago
Depends on your platform. For RedHat as an example they offer OpenJDK builds that are free with LTS. Source: almost 4 years ago
Xcode - Xcode is Apple’s powerful integrated development environment for creating great apps for Mac, iPhone, and iPad. Xcode 4 includes the Xcode IDE, instruments, iOS Simulator, and the latest Mac OS X and iOS SDKs.
OpenJDK - OpenJDK is the free version of the Java development platform.
IntelliJ IDEA - Capable and Ergonomic IDE for JVM
AdoptOpenJDK - The code for Java is open source and available at OpenJDK™.
VS Code - Build and debug modern web and cloud applications, by Microsoft
Microsoft OpenJDK - The Microsoft Build of OpenJDK is a new no-cost long-term supported distribution and Microsoft’s new way to collaborate and contribute to the Java ecosystem.