Java: how to detect the current java runtime is a JRE or JDK?

Question

I got a Java application, I want to provide user ability to compile Java source code (Using JavaCompiler interface)

If the user run the application on a JRE, my application should tell user that the no JavaCompiler instance aviable.

so how to detect JDK or JRE in java programe?

Ejaculatory

Answer 1

You can request an implementation of JavaCompiler from ToolProvider. If it returns null, there is no implementation of JavaCompiler available:

JavaCompiler c = ToolProvider.getSystemJavaCompiler();
if (c == null) {
    // JRE
}

Glossography

I'm not sure if that works - it seems like the JavaCompiler interface itself is always available, but the distinction of JDK vs. JRE depends on there being an implementation. – Rothman

it works great when the JDK is installed properly, and javac can be found on the classpath. but what if i want to allow a user to run it, even if the javac cannot be reached? all i want to know is if i'm running on JDK or JRE... see this link - it can be solved if the user defines the environment variable. but since i have no need for the javac, i don't want to bother the user with this extra configuration overhead... – Ness

Not working on JDK7x64, are we sure this still works? – Selftaught

Answer 2

Take a look at stackoverflow thread - How to determine if the Java VM is installed on Windows? , How do I detect which kind of JRE is installed — 32bit vs. 64bit and How can I detect the installed Sun JRE on Windows?

You can use System.getProperties()/System.getProperty() method.

Ultimogeniture