Java实现Vector主要操作

package Eric.ADT;

import org.junit.Test;

/**
 * <p>
 * Title:MyVector
 * </p>
 * <p>
 * Description:Implement vector by java
 * </p>
 * <p>
 * Location:Frostburg
 * </p>
 * 
 * @author: Eric.Chen
 * @date:2017年9月17日上午9:15:19
 */
public class MyVector implements JavaVector, Cloneable {
    private static final int InicialCapacity = 100;
    private int minCapacity;
    private Object[] elementData;
    private int size;

    public MyVector() {
        elementData = new Object[InicialCapacity];
        size = 0;
        minCapacity += elementData.length;//扩容时的增量
    }

    // 1.添加元素
    @Override
    public void append(Object element) {
        if (size == elementData.length) {
            ensureCapacity(InicialCapacity);
        } else {
            elementData[size] = element;
            size++;
        }

    }

    // 2.清空向量
    @Override
    public void clear() {
        int size = elementData.length;
        for (int i = 0; i < elementData.length; i++) {
            elementData[i] = (Integer) null;
            size--;
        }

    }

    // 3.判断向量中是否含有特定元素
    @Override
    public boolean contains(Object element) {
        for (int i = 0; i < elementData.length; i++) {
            if (element.equals(elementData[i]))
                return true;
        }
        return false;
    }

    // 4.查找指定元素的角标
    @Override
    public Object elementAt(int index) {
        for (int i = 0; i < elementData.length; i++) {
            if (elementData[i].equals(elementData[index])) {
                return elementData[i];
            }
        }
        return null;
    }

    // 5.查找指点角标对应的值
    @Override
    public int indexOf(Object element) {
        for (int i = 0; i < elementData.length; i++) {
            if (elementData[i].equals(element))
                return i;
        }
        return -1;
    }

    // 6.判断向量是否为空
    @Override
    public boolean isEmpty() {
        if (size() == 0)
            return false;
        else
            return true;
    }

    // 7.删除指定角标的元素
    @Override
    public void removeAt(int index) {
        for (int i = index; i < elementData.length - 1; i++) {
            elementData[i] = elementData[i + 1];
        }
        Object[] temp = new Object[elementData.length - 1];
        for (int i = 0; i < elementData.length - 1; i++) {
            temp[i] = elementData[i];
        }
        elementData = temp;

    }

    // 8.移除指定元素
    @Override
    public void remove(Object element) {
        // TODO Auto-generated method stub
        for (int i = 0; i < elementData.length; i++) {
            if (element.equals(elementData[i])) {
                removeAt(i);
            }
        }

    }

    // 9.用指定的元素代替指定角标的值
    @Override
    public void replace(int index, Object element) {
        // TODO Auto-generated method stub
        elementData[index] = element;

    }

    // 10.返回向量中的元素个数，不包括null
    @Override
    public int size() {
        int num = 0;
        for (int i = 0; i < elementData.length; i++) {
            if (elementData[i] != null) {
                num++;
            }
        }
        return num;
    }

    // 11.当数组长度不够时进行扩容
    @Override

    public boolean ensureCapacity(int minCapacity) {
        Object[] temp = new Object[elementData.length + minCapacity];
        for (int i = 0; i < temp.length; i++) {
            temp[i] = elementData[i];
        }
        elementData = temp;
        return true;
    }

    // 12.反转数组
    @Override
    public void reverse() {
        Object[] data = new Object[elementData.length];
        int j = data.length - 1;
        for (int i = 0; i < size(); i++) {
            data[j] = elementData[i];
            j--;
        }
        elementData = data;
    }

    // 13.克隆数组
    @Override
    public Object clone() {
        Object[] cloneArray = new Object[size()];
        for (int i = 0; i < size(); i++) {
            cloneArray[i] = elementData[i];
        }
        return cloneArray;

    }

    // 14.移除指定区域的元素 包括开头，不包括结尾
    @Override
    public void removeRange(int fromIndex, int toIndex) {
        Object[] temp = new Object[size() - (toIndex - fromIndex)];
        int j = 0;
        for (int i = 0; i < size(); i++) {

            if (i < fromIndex || i >= toIndex) {
                temp[j] = elementData[i];
                j++;
            }
        }

        elementData = temp;
    }

    // 15.没看懂要干什么，哈哈哈
    @Override
    public void merge(MyVector vector2) {
        // TODO Auto-generated method stub
    }

    // 16.在指定位置插入指定元素
    @Override
    public void insertAt(int index, Object element) {
        for (int i = size() - 1; i >= index; i--) {
            elementData[i + 1] = elementData[i];
        }
        elementData[index] = element;
        size++;
    }

    // 17.将数组转化成字符串返回
    @Override
    public String toString() {
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < size(); i++) {
            sb.append(elementData[i]);
            sb.append(",");
        }
        String substring = sb.substring(0);
        return substring;
    }

    // 18.单元测试块
    @Test
    public void Test() {
        append(20);
        append(30);
        append(40);
        append(50);
        append(60);
        append(10);
        append(70);
        String strArray = toString();
        System.out.println(strArray);
    }
}