java - Java RecursiveLinkedList にはメソッドが含まれています

Question

私は単純なlinkedListクラスに取り組んでいます。このクラスの要件の1つは、recursを使用してcontainsメソッドを実装し、メソッドを追加し、メソッドを削除することです。

例に基づいて、削除メソッドを実装したことがわかりましたが、含まれているとエラーがスローされ続けます。

私の含むメソッドの何が問題なのかを指摘するのを手伝ってくれる人はいますか?

public class RecursiveLinkedList {

private int value;
private RecursiveLinkedList next;

/*
 * Default Constructor
 * 
 * @param value an absolute int value for the current Node
 * @param next an absolute RecursiveLinkedList value for the current Node
 */
public RecursiveLinkedList(int value, RecursiveLinkedList next) {
    this.value = value;
    this.next = next;
}

/*
 * Constructor Empty, when user supplies an empty for the construcot use 
 * value = - 1 and next = null as input parameters
 * 
 * @param value an absolute int value for the current Node
 * @param next an absolute RecursiveLinkedList value for the current Node
 */
public static final RecursiveLinkedList EMPTY = new RecursiveLinkedList(-1, null) 
{
    public RecursiveLinkedList remove(int n) { return this; };

    public String toString() { return ""; };
};

public RecursiveLinkedList remove(int n) {
    if (value == n){
        return next;
    }
    //Call the remove method of the next Node if the selected Node is not the current node
    return new RecursiveLinkedList(value, next.remove(n));
}

public boolean contains(int n) {
    if (value == n){
        return true;
    }else if(next == null){
        return false;
    }
    return new RecursiveLinkedList(value, next).contains(n);
} 

public String toString() {
    return value + "," + next.toString();
}

public static void main(String[] args) {
    RecursiveLinkedList l = new RecursiveLinkedList(1,
                    new RecursiveLinkedList(2, 
                    new RecursiveLinkedList(2,
                    new RecursiveLinkedList(3, 
                    new RecursiveLinkedList(4, EMPTY)))));
    System.out.println(" Test to String Method : " + l.toString());
    System.out.println(" Test remove method " + l.remove(1).toString());
    System.out.println(" Test contains method " + String.valueOf(l.contains(4)));
}

}