java list内部构造

看代码吧，如下：

package com.Core.datastructure;

import java.lang.reflect.Array;

import java.util.Collection;

import junit.framework.TestCase;

public class ListDemo<T> {

private int capacity;

private int size = 0;

private Object[] elementData;

public ListDemo(int capcity) {

this.capacity = capcity;

elementData = new Object[capacity];

}

public ListDemo() {

this(10);

}

public void growCapacity(int growRank) {

Object newArr = Array.newInstance(elementData.getClass().getComponentType(), capacity

+ growRank);

System.arraycopy(elementData, 0, newArr, 0,

Array.getLength(elementData));

elementData = (Object[]) newArr;

}

public void insert(T t) {

if (capacity > size) {

elementData[size] = t;

size++;

} else {

growCapacity(1);

elementData[size] = t;

size++;

}

}

public void insert(int index, T t) {

if (index < 0 || index >= size)

throw new IndexOutOfBoundsException("Index: " + index + ", Size: "

+ size);

growCapacity(1);

System.arraycopy(elementData, index, elementData, index + 1, size

- index);

elementData[index] = t;

}

public boolean remove(T t) {

if (t == null) {

for (int i = 0; i < size; i++) {

if (getEle(i) == null) {

fastRemove(i);

return true;

}

}

} else {

for (int i = 0; i < size; i++) {

if (getEle(i).equals(t)) {

fastRemove(i);

return true;

}

}

}

return false;

}

public T remove(int index) {

            if(index < 0 || index >= size){

            throw new IndexOutOfBoundsException("Index: " + index + ", Size: "

    + size);

            }

            Object obj = elementData[index];

           fastRemove(index);

           return (T) obj;

}

public void fastRemove(int index) {

int numMoved = size - index - 1;

System.arraycopy(elementData, index + 1, elementData, index, numMoved);

elementData[--size] = null;

}

public T getEle(int index) {

return (T) elementData[index];

}

}