JUnit 4 compare Sets

You can assert that the two Sets are equal to one another, which invokes the Set equals() method.

public class SimpleTest {

    private Set<String> setA;
    private Set<String> setB;

    @Before
    public void setUp() {
        setA = new HashSet<String>();
        setA.add("Testing...");
        setB = new HashSet<String>();
        setB.add("Testing...");
    }

    @Test
    public void testEqualSets() {
        assertEquals( setA, setB );
    }
}

This @Test will pass if the two Sets are the same size and contain the same elements.

with hamcrest:

assertThat(s1, is(s2));

with plain assert:

assertEquals(s1, s2);

NB:t the equals() method of the concrete set class is used

As an additional method that is array based ... you can consider using unordered array assertions in junitx . Although the Apache CollectionUtils example will work, there is a pacakge of solid assertion extensions there as well :

I think that the

ArrayAssert.assertEquivalenceArrays(new Integer[]{1,2,3}, new Integer[]{1,3,2});

approach will be much more readable and debuggable for you (all Collections support toArray(), so it should be easy enough to use the ArrayAssert methods.

Of course the downside here is that, junitx is an additional jar file or maven entry...

 <dependency org="junit-addons" name="junit-addons" rev="1.4"/>

Check this article. One example from there:

@Test  
public void listEquality() {  
    List<Integer> expected = new ArrayList<Integer>();  
    expected.add(5);  

    List<Integer> actual = new ArrayList<Integer>();  
    actual.add(5);  

    assertEquals(expected, actual);  
}  

I like the solution of Hans-Peter Störr... But I think it is not quite correct. Sadly containsInAnyOrder does not accept a Collection of objetcs to compare to. So it has to be a Collection of Matchers:

assertThat(set1, containsInAnyOrder(set2.stream().map(IsEqual::equalTo).collect(toList())))

The import are:

import static java.util.stream.Collectors.toList;
import static org.hamcrest.Matchers.containsInAnyOrder;
import static org.junit.Assert.assertThat;