java dynamic classloader

Question

how can I dynamically load a class in Java with two parameters which are the absolute filepath of the class file and the name of the method I wish to call?

eg path: c:\foo.class method: print()

I am just interested in the basics as a simple cmd line tool. A code example would b appreciated.

cheers hoax

Answer 1

Check out this example:

// Create a File object on the root of the directory containing the class file
File file = new File("c:\\myclasses\\");

try {
    // Convert File to a URL
    URL url = file.toURL();          // file:/c:/myclasses/
    URL[] urls = new URL[]{url};

    // Create a new class loader with the directory
    ClassLoader cl = new URLClassLoader(urls);

    // Load in the class; MyClass.class should be located in
    // the directory file:/c:/myclasses/com/mycompany
    Class cls = cl.loadClass("com.mycompany.MyClass");
} catch (MalformedURLException e) {
} catch (ClassNotFoundException e) {
}

After this, you could do something like this to first create a new instace using the default constructor and invoking the method "print" without arguments:

Object object = cls.newInstance();
cls.getMethod("print").invoke(object);