How to use varargs as the parameter of Constructor

问题:

I have a java class like below which I want to create an instance of this class dynamically by using class name.

class Demo {
    public Demo(String... s) {
    //some initialization here.
    }
}

And I want to create an object using following code

Class<?> klass = Class.forName("Demo");

Constructor<?> con = klass.getConstructor("**what should be here**");

Object obj = con.newInstance(param1, param2, ...);

回答1:

String... is just String[] so you can use

Constructor<?> con = klass.getConstructor(String[].class);

Note that you need to invoke the constructor like

Object o = con.newInstance((Object) new String[] {"first", "second", "more"});

with the cast to (Object) for a varargs invocation.