我正在尝试创建一个循环的LinkedList，请告诉我它是否是正确的方法

Question

i have implemented logic like if i am giving a index that is not yet there then it will change the index to the reminder (Same like rotated i guess ).

import java.util.LinkedList;

public class MycircularlinkedList extends LinkedList {

    private static int count = 0;

    public Object get(int i) {
        System.out.println("count==" + count);
        if (i > count) {
            i = i % count;
            return super.get(i);

        } else {
            return super.get(i);
        }

    }

    public boolean add(Object o) {

        super.add(o);
        count++;
        return true;
    }

    public void add(int i, Object o) {
        if (i > count)
            i = i % count;
        super.add(i, o);
        count++;
    }
}

Answer 1

A couple of points I can see:

1. count is static, this means you're only ever going to have one number here. Probably not what you want
2. count is redundant, use Collection#size()
3. The great thing about mod ( % ) is that it works for all numbers, you don't need to have the conditional. 2 % 12 == 14 % 12 == -10 % 12
4. If you're getting rid of the count property, you can get rid of your overridden #add(Object o) logic and just do return super.add(o);

Answer 2

我发现您的代码存在一些问题：如果count == 0并且如果我使用方法add（7，obj），则7％0将引发ArithmeticException.count应该声明为private，因为您可能有两个类实例。另外，您还需要检查poll \\ offerLast方法是否满足您的需求，因为您不能限制任何客户端代码来避免使用它们。最后，需要重写clone \\ readObject \\ writeObject才能包含count变量。

Answer 3

You're close.

(1) The term " circular linked list " is well-known to mean a list where the tail links back to the head (and vice versa if it's a doubly-linked list). Yours is more like a "circular buffer" stored in a linked list. We could call it LinkedListCircularBuffer or something.

(2) The class should be parameterized by the element type, thus

public class LinkedListCircularBuffer<E> extends LinkedList<E> {
  @Override
  public E get(int i) {
    return super.get(i % size()); // simpler and faster without an "if"
  }
}

(3) You can call size() instead of all the code to maintain another count .

(4) Your add(int i, Object o) method doesn't support the case where i == size() , but you can fix that by not overriding add() at all.

(5) Overridden methods need the @Override annotation.

(6) It's good style to always put braces around each "then" and "else" clause. Code like

if (i > count)
  i = i % count;

is fragile, eg adding a println() statement into that "then" clause will break it.