For checking whether a linked list is a palindrome,I would really appreciate if anyone could tell what is wrong in the following code

Question

This code is working fine but when two negative Integers having more than two digits are compared its returning false. I would really appreciate if anyone could tell me what is wrong in the following code.
eg.. [-200,-200] this is a palindrome but when compared its returning false

class Solution {
public boolean isPalindrome(ListNode head) {
    ArrayList<Integer>list=new ArrayList<>();
    ListNode temp=head;
    while(temp!=null){
        list.add(temp.val);
        temp=temp.next;
    }
    int i=0,j=list.size()-1;
    while(i<j){
        if(list.get(i)!=list.get(j)) return false;
        i++;j--;
    }
    return true;
}

}