Java Trick: Generic Array Converter

I had a problem of increasing size of the array. Of course I have to copy the array. But it is not easy with java Generics, because of the following problem:

public class ArrayUtils<T>{
 public T[] resizeArray(T[] source, int offset){
  int length = source.length+offset;
  Object[] aNew = new Object[length];
  System.arraycopy(source, 0, aNew, 0, source.length);
  return (T[])aNew;
 }
}

Of course you can compile the ArrayUtils class, but you cannot use this method as shown in the following code segment:

 public static void main(String[] args){
  Integer[] ints = new Integer[2];
  ints[0]=0;
  ints[1]=1;
  Integer[] newInts =  new ArrayUtils<integer>().resizeArray(ints, 3);
  System.out.println(newInts.length);
 }

Here the error:

Exception in thread "main" java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to [Ljava.lang.Integer;
 at net.au.abc.abcid.test.ArrayCopyTest.main(ArrayCopyTest.java:9)

the problem, aNew never is possible to cast to the type T because it is created as an Object type. I found a very good answer with help of the book: Core Java: Volume I—Fundamentals, Ninth Edition. It is easy with java reflections as shown in the line# 7 to 9. getClass().getComponentType() return the type of the array elements.

import java.lang.reflect.Array;

public class ArrayUtils<T>{
 public T[] resizeArray(T[] source, int offset){
  int length = source.length+offset;
  
  Class arrayClass =  source.getClass();
  Class elementType =  arrayClass.getComponentType();
  Object aNew = Array.newInstance(elementType, length);
  System.arraycopy(source, 0, aNew, 0, source.length);
  return (T[])aNew;
 }
}

If you need you can make the method static by changing it signature to

public <t> T[] resizeArray(T[] source, int offset){ 

.