循环array

public class CircularArray<E> {// 一个循环array
    private int mNextWriter;
    private boolean mHasWrapped;
    private int mMaxCount;
    Object mList[];
    public Circular(int count){
        mMaxCount = count;
        clear();
    }
    public void clear(){// 重置list
        mNextWriter = 0;
        mHasWrapped = false;
        mList = new Object[mMaxCount];
    }
    public void add(E object){// 添加数据到list的结尾
        mList[mNextWroter] = object;
        ++mNextWriter;
        if(mNextWriter == mMaxCount){
            mNextWriter = 0;
            mHasWrapped = true;
        }
    }
    public int count(){
        if(mHasWrapped){
            return mMaxCount;
        }else{
            return mNextWriter;
        }
    }
    public E getFree(){// list数据未填充满则返回null,否则返回下一个应该被覆盖的数据
        if(!mHasWrapped){
            return null;
        }else {
            return (E)mList[mNextWriter];
        }
    }
    public E get(int index){//获取在index的数据, list数据未满时起始位置为0, 否则起始位置为下一个将被覆盖的位置
        if(mHasWrapped){
            int wrappedIndex = index + mNextWriter;
            if(wrappedIndex >= mMaxCount){
                wrappedIndex -= mMaxCount;
            }
            return (E)mList[wrappedIndex];
        }else{
            return (E)mList[index];
        }
    }
}