How to create an array of instances of generic nested classes?

I try to create an array of instances of inner class objects, which are derived from generic inner classes.

When I do this

delivery.columns = new Delivery.Column[] { delivery.new Number (), delivery.new Date () };

I get the warnings:

<!-- language: none -->

Table.java:58: warning: [rawtypes] found raw type: Table.Column
delivery.columns = new Delivery.Column[] { delivery.new Number (), delivery.new Date () };
^
missing type arguments for generic class Table.Column<V>
where V is a type-variable:
V extends Object declared in class Table.Column
Table.java:58: warning: [unchecked] unchecked conversion
delivery.columns = new Delivery.Column[] { delivery.new Number (), delivery.new Date () };
^
required: Table.Column<Object>[]
found:    Table.Column[]
2 warnings

And if I follow the requirement in the warning and do the following

delivery.columns = new Delivery.Column<Object>[] { delivery.new Number (), delivery.new Date () };

I get the following errors:

<!-- language: none -->

Table.java:58: error: incompatible types: Delivery.Number cannot be converted to Table.Column<Object>
delivery.columns = new Delivery.Column<Object>[] { delivery.new Number (), delivery.new Date () };
^
Table.java:58: error: incompatible types: Delivery.Date cannot be converted to Table.Column<Object>
delivery.columns = new Delivery.Column<Object>[] { delivery.new Number (), delivery.new Date () };
^
Table.java:58: error: generic array creation
delivery.columns = new Delivery.Column<Object>[] { delivery.new Number (), delivery.new Date () };
^
3 errors

How to solve this problem without warning and error?

This is the complete example:

import java.util.stream.Collectors;
import java.util.stream.Stream;
import static java.lang.System.err;
abstract class Table
{
String           name = null;
Column<Object>[] columns = null;
abstract class Column<V>
{
String  name = null;
Integer type = null;
class Value
{
V value;
Value (V value)
{
this.value = value;
}
}
public String toString ()
{
return name + ": " + type.toString();
}
}
public String toString ()
{
return this.name + " ("
+ Stream.of(columns).map (Column<Object>::toString).collect (Collectors.joining (", "))
+ ")";
}
}
class Delivery extends Table
{
{ name = "Delivery"; }
class Number extends Delivery.Column<String>
{
{ name = "Number"; }
}
class Date extends Delivery.Column<String>
{
{ name = "Date"; }
}
public static void main (String[] args)
{
String[] strings;
Delivery delivery = new Delivery ();
delivery.columns = new Delivery.Column<Object>[] { delivery.new Number (), delivery.new Date () };
err.println (delivery);
}
}

I am not sure if it is a proper solution, it's more like a workaround using a List<Column<?>> container (as @Andy Turner suggested in the comments).
Then the list can be converted into array of columns if needed.

    // abstract class Table
    protected List<Column<?>> columns;
    protected Column<?>[] arrColumns = null;

    public Column<?>[] getColumnsAsArray() {
        if (null == columns) {
            return null;
        }
        Column<?>[] arr = (Column<?>[]) Array.newInstance(Column.class, columns.size());
        return columns.toArray(arr);
    }

    public String toString() {
        return this.name 
            + "\nlist: (" + columns.stream().map(Column::toString).collect(Collectors.joining(", ")) + ")"
            + "\narr: (" + Stream.of(arrColumns).map(Column::toString).collect(Collectors.joining(", ")) + ")";
    }

So, the list of columns can be created and converted to array as shown below:

public class Main {

  public static void main(String[] args) {
    Delivery delivery = new Delivery();
    delivery.columns = Arrays.asList(delivery.new Number(), delivery.new Date());

    delivery.arrColumns = delivery.getColumnsAsArray();

    err.println(delivery);

    Arrays.stream(delivery.arrColumns)
          .map(Object::getClass)
          .forEach(System.out::println);
  }
}

class Delivery extends Table {
  { name = "Delivery"; }
 
  class Number extends Table.Column<Number> {
    { name = "Number"; type = 1; }  // define _type_ to prevent NPE in Column<V>::toString
  }
 
  class Date extends Table.Column<String> {
    { name = "Date"; type = 10; } // define _type_ to prevent NPE
  }
}

Output

# stderr
Delivery
list: (Number: 1, Date: 10)
arr: (Number: 1, Date: 10)
# stdout
class Delivery$Number
class Delivery$Date

Online demo (updated)

Verified with compiler option -Xlint:all