自己写的一个双向链表容器

package com.lovo;

public class SuperLinkedList <T>{
    private int size;
    private SuperLinkedListNode<T> firstNode;
    private SuperLinkedListNode<T> lastNode;
    /**
     * 添加元素（添加在链表的末尾）
     * @param o
     */
    public void add(T o) {
        SuperLinkedListNode<T> node = new SuperLinkedListNode<T>();
        if (size == 0) {
            node.setContent(o);
            node.setNextNode(null);
            node.setLastNode(null);
            firstNode = node;
            lastNode = node;
            size++;
        }else {
            if (!isRepeat(o)) {
                node.setContent(o);
                node.setNextNode(null);
                node.setLastNode(lastNode);
                lastNode.setNextNode(node);
                lastNode = node;
                size++;
            }
        }
    }
    /**
     * 插入元素
     * @param o 元素值
     * @param index 元素位置
     */
    public void insert(T o,int index) {
        SuperLinkedListNode<T> node = new SuperLinkedListNode<T>();
        if (index >= size || index < 0) {
            throw new ArrayIndexOutOfBoundsException();
        }else {
            SuperLinkedListNode<T> tempNode = firstNode;
            for (int i = 0; i < index; i++) {
                tempNode = tempNode.getNextNode();
            }
            if (!isRepeat(o)) {
                node.setContent(o);
                node.setNextNode(tempNode);
                if (index != 0) {
                    SuperLinkedListNode<T> lastNode = tempNode.getLastNode();
                    node.setLastNode(lastNode);
                    lastNode.setNextNode(node);
                    tempNode.setLastNode(node);
                } else {//插入的是头元素
                    node.setLastNode(null);
                    tempNode.setLastNode(node);
                    firstNode = node;
                }
                size++;
            }
        }
    }
    /**
     * 按索引取元素
     * @param index 下标值
     * @return 下标值对应的元素
     */
    public SuperLinkedListNode<T> get(int index) {
        if (index < 0 || index >= size) {
            throw new ArrayIndexOutOfBoundsException();
        }
        SuperLinkedListNode<T> node = firstNode;
        for (int i = 0; i < index; i++) {
            node = node.getNextNode();
        }
        return node;
    }
    /**
     * 通过索引删除元素
     * @param index 索引值
     */
    public void removeAt(int index) {
        if (index < 0 || index >= size) {
            throw new ArrayIndexOutOfBoundsException();
        }
        SuperLinkedListNode<T> node = firstNode;
        for (int i = 0; i < index; i++) {
            node = node.getNextNode();
        }
        SuperLinkedListNode<T> nextNode = node.getNextNode();
        SuperLinkedListNode<T> lastNode = node.getLastNode();
        if (nextNode == null) {
            if (lastNode != null) {//size为1
                node.clear();
                lastNode.setNextNode(null);
                this.lastNode = lastNode;
            }
        }else {
            if (lastNode == null) {
                nextNode.setLastNode(null);
                firstNode = nextNode;
            }else {
                lastNode.setNextNode(nextNode);
                nextNode.setLastNode(lastNode);
            }
        }
        node.clear();
        size--;
    }
    /**
     * 通过元素值删除元素
     * @param o 删除的元素
     */
    public void remove(T o) {
        if (o != null) {
            SuperLinkedListNode<T> node = firstNode;
            for (int i = 0; i < size; i++) {
                if (o.equals(node.getContent())) {
                    removeAt(i);
                }
                node = node.getNextNode();
            }
        }
    }
    /**
     * 清空容器
     */
    public void clear() {
        SuperLinkedListNode<T> node = firstNode;
        for (int i = 0; i < size - 1; i++) {
            SuperLinkedListNode<T> tempNode = node.getNextNode();
            node.clear();;
            node = tempNode;
        }
        node.clear();
        size = 0;
    }
    /**
     * 得到容器大小
     * @return
     */
    public int size() {
        return size;
    }
    /**
     * 判断元素值是否重复（已经存在）
     * @param o 要比较的值
     * @return true:相同 false:不相同
     */
    private boolean isRepeat(T o){
        SuperLinkedListNode<T> tempNode = firstNode;
        boolean flag = false;
        for (int i = 0; i < size; i++) {
            if(o.equals(tempNode.getContent())){
                flag = true;
            }
            tempNode = tempNode.getNextNode();
        }
        return flag;
    }
}

package com.lovo;

public class  SuperLinkedListNode<T>{
    private SuperLinkedListNode<T> nextNode;
    private SuperLinkedListNode<T> lastNode;
    private T content;
    /**
     * 清空节点
     */
    public void clear() {
        nextNode = null;
        lastNode = null;
        content = null;
    }
    public SuperLinkedListNode<T> getNextNode() {
        return nextNode;
    }
    public void setNextNode(SuperLinkedListNode<T> nextNode) {
        this.nextNode = nextNode;
    }
    public SuperLinkedListNode<T> getLastNode() {
        return lastNode;
    }
    public void setLastNode(SuperLinkedListNode<T> lastNode) {
        this.lastNode = lastNode;
    }
    public T getContent() {
        return content;
    }
    public void setContent(T content) {
        this.content = content;
    }
    @Override
    public String toString() {
        return "SuperLinkedListNode [content=" + content + "]";
    }
    
}