Check if an ArrayList contains every element from another ArrayList (or Collection)

There is probably a simple one-liner that I am just not finding here, but this is my question:

How do I check if an ArrayList contains all of the objects in another ArrayList? I am looking (if it exists) for something along the lines of:

//INCORRECT EXAMPLE:
if(one.contains(two))
{
    return true;
}
else
{
    return false;
}

For example:

ArrayList one = {1, 2, 3, 4, 5}

ArrayList two = {1, 2, 3} --> True
ArrayList two = {} --> True
ArrayList two = {1, 2, 3, 4, 5} --> True
ArrayList two = {1, 5, 2} --> True
ArrayList two = {1, 7, 4} --> False
ArrayList two = {0, 1, 3} --> False
ArrayList two = {4, 5, 6} --> False
ArrayList two = {7, 8, 9} --> False

Solution 1:

There is a method called containsAll declared in the java.util.Collection interface. In your setting one.containsAll(two) gives the desired answer.

Solution 2:

Per the List interface:

myList.containsAll(...);

Solution 3:

Take a look at containsAll(Collection<?> c) method from List interface. I think it is what you are looking for.

Solution 4:

Here is another example use of containsAll() that I have used for asserting that two arrays are equal in JUnit testing:

List<String> expected = new ArrayList<String>();
expected.add("this");
expected.add("that");
expected.add("another");

List<String> actual = new ArrayListString();
actual.add("another");
actual.add("that");
actual.add("this");

Assert.assertTrue("The lists do not match!", expected.containsAll(actual));

Solution 5:

You can use containsAll method of the list to do the check. However, this is a linear operation. If the list is large, you should convert it to HashSet first, and then perform containsAll:

HashSet tmp = new HashSet(one);
if (tmp.containsAll(two)) {
    ...
}

If the length of one is N and the length of two is M, this solution has time complexity of O(M+N); the "plain" containsAll has the complexity of O(M*N), which may be significantly worse.