Is it possible in java to programmatically run a java program?
For example, having a runnable class loaded and run as a thread?
EDIT
I see that I should have been more precise :)
I've got a .class file that I want to read and run.
The idé is that I have no ide what kind of program it is, only that it is a valid class file. What I want to do is to be able to run the .class file as if I myself had written and compiled it.
Something like this, maybe?
new Thread(new Runnable() {
@Override
public void run() {
MyRunnableClass.main(new String[]{});
}
}).start();
A runnable class is a normal class with a static main method. We can call that method like any other method. If we do that in a Thread, then we'll have something similiar to what the JVM would do when starting an application.
Full version with reflection:
public static void start(final String classname, final String...params) throws Exception { // to keep it simple
final Class<?> clazz = Class.forName(classname);
final Method main = clazz.getMethod("main", String[].class);
new Thread(new Runnable() {
@Override
public void run() {
try {
main.invoke(null, new Object[]{params});
} catch(Exception e) {
throw new AssertionError(e);
}
}
}).start();
}
Use it like
start("com.example.myApp", "param1", "param2");
and it will execute the main method of that class in a new Thread.
Yes, you can do it through reflection if you want to execute the code within your process.
I haven't tested this code, but it should looks something like this:
Class<? extends Runnable> theClass =
Class.forName(fullyQualifiedClassName).asSubclass(Runnable.class);
Runnable instance = theClass.newInstance();
new Thread(instance).start();
I found an interresting artivle on how to do that. See here.
