Remove duplicate elements from a linked list in java

package com.w3spoint;
 
public class LinkedList {	 
    static Node head; 
    static class Node { 
        int data;
        Node next; 
        Node(int data) {
            this.data = data;
            this.next = null;
        }
    }
 
    void removeDuplicates() {
        Node ptr1 = null, ptr2 = null, duplicate = null;
        ptr1 = head; 
        while (ptr1 != null && ptr1.next != null) {
            ptr2 = ptr1;
            while (ptr2.next != null) { 
                if (ptr1.data == ptr2.next.data) { 
                	duplicate = ptr2.next;
                    ptr2.next = ptr2.next.next;
                    System.gc();
                } else {
                    ptr2 = ptr2.next;
                }
            }
            ptr1 = ptr1.next;
        }
    }
 
    void printList(Node node) {
        while (node != null) {
            System.out.print(node.data + " ");
            node = node.next;
        }
    }
 
    public static void main(String[] args) {
        LinkedList list = new LinkedList();
        list.head = new Node(11);
        list.head.next = new Node(17);
        list.head.next.next = new Node(11);
        list.head.next.next.next = new Node(19);
        list.head.next.next.next.next = new Node(45);
 
        System.out.println("Linked List : ");
        list.printList(head);
 
        list.removeDuplicates();
        System.out.println("");
        System.out.println("Linked List after removing duplicates : ");
        list.printList(head);
    }
}

Linked List : 
11 17 11 19 45 
Linked List after removing duplicates : 
11 17 19 45