java基础之自定义队列实现

package shujujiegou;/** * Created by lcc on 2017/6/21. */public class DuiLie<T> {    public static void main(String[] args) {        DuiLie<String> lcc = new DuiLie<String>();        lcc.add("shuangqi");        lcc.add("keai");        lcc.add("love");        lcc.add("xuyingming");        lcc.add("haojiuhaojiu");        System.out.println(lcc.Print());        System.out.println("----------");        DuiLie<String> xuyingming = new DuiLie<String>(3);        xuyingming.add("lcc");        xuyingming.add("lcc");        xuyingming.add("lcc");        int size = xuyingming.size();        xuyingming.remove();        int size1 = xuyingming.size();        xuyingming.clear();        int size2 = xuyingming.size();        System.out.println("shanchuqian " + size + " shanchuhou " + size1+ " clearhou " +size2);    }    private final int DEFAULT_SIZE = 10;    private Object elementData[];    private int front = 0;    private int rear = 0;    private int capactiy;    public DuiLie() {        capactiy = DEFAULT_SIZE;        elementData = new Object[capactiy];    }    public DuiLie(int initsize) {        this.capactiy = initsize;        elementData = new Object[capactiy];    }    public DuiLie(T element) {        this();  //   调用空的构造方法，相当于capactiy =  DEFAULT_SIZE;  elementData = new Object[capactiy];        elementData[front] = element;        front++;    }    public DuiLie(T element, int initsize) {        this(initsize);        elementData[front] = element;        front++;    }    public int size() {        return front - rear;    }    public boolean empty() {        return front == rear;    }    public void add(T element) {        if (rear > capactiy - 1) {            throw new IndexOutOfBoundsException("the duilie is full!");        }        elementData[rear++] = element;    }    public T remove() {        if (empty()) {            throw new IndexOutOfBoundsException("duilie is empty");        }        T oldElement = (T) elementData[front];        elementData[front] = null;        front++;        return oldElement;    }    public T element() {        if (empty()) {            throw new IndexOutOfBoundsException("duilie is empty");        }        return (T) elementData[front];    }    private void fill(Object[] a, Object val) {        for (int i = 0, len = a.length; i < len; i++)            a[i] = val;    }    public void clear() {        fill(elementData, null);        front = 0;        rear = 0;    }    public String Print() {        if (empty())            return "[]";        StringBuffer sb = new StringBuffer("[");        for (int i = front; i < rear; i++) {            sb.append(elementData[i] + ",");        }        int len = sb.length();        return sb.replace(len - 2, len, "]").toString();    }}