Combine two lists - in java

Write a method that returns the union of two array lists of integers using the following header:

public static ArrayList union ( ArrayList list1, ArrayList list2)

For example, the union of two array lists {2, 3, 1, 5} and {3, 4, 6} is {2, 3, 1, 5, 3, 4, 6}. Write a test program that prompts the user to enter two lists, each with five integers, and displays their union. The numbers are separated by exactly one space in the output. Here is a sample run:

Enter five integers for list1: 3 5 45 4 3 Enter five integers for list2: 33 51 5 4 13 The combined list is 3 5 45 4 3 33 51 5 4 13