How do you create an inner class object with reflection? Both Inner and Outer classes have default constructors that take no parameters
Outer class {
Inner class{
}
public void createO() {
Outer.Inner ob = new Inner ();//that works
Inner.class.newInstance(); //<--why does this not compile?
}
}
That means you can never construct an inner class using Class.newInstance; instead, you must use the constructor that takes a single Outer instance. Here's some example code that demonstrates its use:
class Outer {
class Inner {
@Override
public String toString() {
return String.format("#<Inner[%h] outer=%s>", this, Outer.this);
}
}
@Override
public String toString() {
return String.format("#<Outer[%h]>", this);
}
public Inner newInner() {
return new Inner();
}
public Inner newInnerReflect() throws Exception {
return Inner.class.getDeclaredConstructor(Outer.class).newInstance(this);
}
public static void main(String[] args) throws Exception {
Outer outer = new Outer();
System.out.println(outer);
System.out.println(outer.newInner());
System.out.println(outer.newInnerReflect());
System.out.println(outer.new Inner());
System.out.println(Inner.class.getDeclaredConstructor(Outer.class).newInstance(outer));
}
}
(Note that in standard Java terminology, an inner class is always non-static. A static member class is called a nested class.)
