I need Java code

If your first name starts with a letter from A-J inclusively: Use the SinglyLinkedList implementation . Write a method for concatenating two singly linked lists L1 and L2, into a single list L that contains all the nodes of L1 followed by all the nodes of L2. Write a main method to test the new method. Hint: Connect the end of L1 into the beginning of L2.

If your first name starts with a letter from K-Z inclusively: Use the DoublyLinkedList implementation . Write a method for concatenating two doubly linked lists L1 and L2, into a single list L that contains all the nodes of L1 followed by all the nodes of L2. Write a main method to test the new method. Hint: Connect the end of L1 into the beginning of L2.