构造一个在运行时确定类型的对象？

Question

So I'm trying to test the methods on a certain class (with a default constructor), and the test methods can only be public and of type void , and must start with "test".

public static void main(String[] args) throws ClassNotFoundException {
    Class<?> c = null;
    c = Class.forName(args[0]);

    System.out.println(c.getName());
    for (Method m : c.getMethods()) {
        if (m.getName().startsWith("test")
                && m.getReturnType().equals(Void.TYPE)
                && m.getModifiers() == Modifier.PUBLIC) {

            Object o = null;

            try {
                o = c.newInstance();
            } catch (InstantiationException | IllegalAccessException ex) {
                System.out.println(ex.getMessage());
            }

            // ???    
        }
    }
}

So, my checks work, but I do not know how to make a new instance of the class and test the method. How would I do this?

Answer 1

Try with:

m.invoke(o);

This will reflectively invoke your method ´m´, given it doesn't receive any arguments.

One note about checking if the method is public . You'd better perform that check this way:

boolean isPublic = Modifier.isPublic(m.getModifiers());

Unless you want to check that the method is only public and has no other modifier, in which case your code is OK.

Exception handling left as an excersice ;)