实现简单的动态数组

自定义一个动态数组类，数组只有在增加元素时才会增加大小，节约空间，适用于修改少、遍历多的操作。

package list;public class DyList<T> {private Object[] elements = null;public DyList(){elements = new Object[0];}public DyList(int size){if (size > 0){elements = new Object[size];}else{elements = new Object[0];}}public void add(T i){Object[] tmp = new Object[elements.length+1];System.arraycopy(elements, 0, tmp, 0, elements.length);tmp[elements.length] = i;elements = tmp;}@SuppressWarnings("unchecked")public T get(int index){return (T)elements[index];}public int size(){return elements.length;}

}

参考： http://www.ibm.com/developerworks/cn/java/j-lo-tomcat1/