Write a JAVA function to find maximum element from doubly linked list

Sure, here is a simple Java function to find the maximum element from a doubly linked list:

class Node {
    int data;
    Node next, prev;
    Node(int data) {
        this.data = data;
        next = prev = null;
    }
}

class LinkedList {
    Node head;

    // Function to find maximum element
    int findMax() {
        if (head == null)
            return Integer.MIN_VALUE;

        int max = head.data;
        Node current = head;

        // Traverse through the list
        while (current != null) {
            if (current.data > max)
                max = current.data;

            current = current.next;
        }

        return max;
    }
}

In this code, we first check if the list is empty. If it is, we return the smallest possible integer value as there is no element in the list. If the list is not empty, we initialize the maximum value as the data of the head node. Then we traverse through the list. For each node, we compare its data with the current maximum value. If it's greater, we update the maximum value. Finally, we return the maximum value after the traversal.