方法的字符串（调用）将引发异常

Question

I want to call a method, given a String. I mean, I have a String which is the name of the method I want to call.

I've seen that the reflection is the way to meet the target but, when I try to get the method (before invoking it), I get an exception.

That's what I have done:

        Method method = Object.class.getMethod("functionToCall", String.class);

Why is this command throwing an exception? What can I do in order to get the method which is going to be invoked?

Thank you very much in advance!

Answer 1

What you are trying in your example is to get the functionToCall method which takes a String as parameter from java.lang.Object class. It won't happen.

However you can use getMethod() and the invoke() combination like this:

The class to work with:

public class MyClass {
    public void myMethod(final String pString) {
        System.out.println("Hello "+pString);
    }
}

And to actually invoke the method

// We get the method myMethod which takes a String.
Method method = MyClass.class.getMethod("myMethod", String.class);
// We call it on a new MyClass instance with "Test" as parameter.
method.invoke(new MyClass(), "Test");