Passing arrays to Parameterized JUnit

The reason why it is failing is because your test expects Integer arrays whereas you are passing Object type. So you are expanding the type. Try this:

@Parameterized.Parameters
    public static Collection testCases() {
        return Arrays.asList(new Integer[][][] {
            {{1,1,1}, {2,2,2}, {3,3,3}},
            {{2,2,2}, {3,3,3}, {4,4,4}}
        });
    }