Resize an Array in Java

Resize an Array in Java

/** * Reallocates an array with a new size, and copies the contents * of the old array to the new array. * @param oldArray  the old array, to be reallocated. * @param newSize   the new array size. * @return          A new array with the same contents. */ private static Object resizeArray (Object oldArray, int newSize) {    int oldSize = java.lang.reflect.Array.getLength(oldArray);    Class elementType = oldArray.getClass().getComponentType();    Object newArray = java.lang.reflect.Array.newInstance(          elementType,newSize);    int preserveLength = Math.min(oldSize,newSize);    if (preserveLength > 0)       System.arraycopy (oldArray,0,newArray,0,preserveLength);    return newArray; }   // Test routine for resizeArray(). public static void main (String[] args) {    int[] a = {1,2,3};    a = (int[])resizeArray(a,5);    a[3] = 4;    a[4] = 5;    for (int i=0; i<a.length; i++)       System.out.println (a[i]); }