Why didn't this array transposed? Code is not an error, it is not transposed,

 public class ShuZuJiCheng {
Public static void main (String args []) {
/* 
* validation: 
*/
//instantiate the object, and through constructing method is passed the length of the array 
ArrayTransposition ar=new ArrayTransposition (8); 
//call the assign method for each element of the array assignment 
Ar. Assign (66); 
Ar. Assign (22); 
Ar. Assign (55); 
Ar. Assign (33); 
Ar. Assign (99); 
Ar. Assign (11); 
Ar. Assign (88); 
Ar. Assign (77); 
//to call the add method expanded scope of array 
Ar. The add (2); 
Ar. Assign (44); 
Ar. Assign (100); 
//call getArr method after the assignment of array 
For (int I=0; iSystem. Out. Print (ar) getArr () [I] + ", "); 
} 
} 
} 
//define an Array class, let the object can be obtained through dynamic expansion of an Array 
The class Array {
//declare an array 
Private int arr []; 
//declare an int variable index, said access to the array index, cannot use a for loop, because access to the array index of object method calls will repeat visit 
//if set for loops, and each object when this method is called, are cycle, so will only assign objects to the last call when the value of the 
Private int index; 
//using the constructor gives the length of the array and the value of each element 
Public Array (int len) {
//require incoming length cannot be less than 0 
If (len<0 {
This. Arr=new int [1]. 
} 
This. Arr=new int [len]; 
} 
/method/set each element of the array, the parameters for each object call assignment number 
Public void the assign (int num) {
//requirement index after the + + operation can not be greater than or equal to the array length 
If (index & lt; This. Arr. Length) {
This. Arr [index++]=num; 
} 
} 
//if you want to extend the length of the array and the elements, you can define the following method 
Public void the add (int) plus {
The int data []=new int [this. Arr. Length + plus]; 
System. Arraycopy (this. Arr, 0, data, 0, enclosing arr. Length); 
This. Arr=data; 
} 
//set up a method to get each element of the array 
Public int [] getArr () {
Return this. Arr; 
} 
} 
//define a subclass of Array class Array has the function of transposed 
The class ArrayTransposition extends Array {
//because subclass instantiation objects before will call the superclass constructor instantiate the superclass object, and as the superclass constructor parameters, is must clearly with super () method 
//call the superclass constructor 
Public ArrayTransposition (int len) {
Super (len); 
} 
//need a method to transpose arrays, and can be transposed after the value of the array is an array by the values of the parent class getArr method already can do 
//so can take override this method to extend this method, because the method override a function is the function of the extension method 
Public int [] getArr () {
Int time=super. GetArr (.) length/2; 
Int head=0; 
Int tail=super. GetArr (.) length - 1. 
For (int I=0; iInt middle=super. GetArr () [head]; 
Super. GetArr () [head]=super. GetArr () (tail); 
Super. GetArr () [tail]=middle; 
The head + +; 
Tail -; 
} 
Return super. GetArr (); 
} 
} 

The output is: