JerseyTest and JUnit throws NullPointerException

Your methods seem to override some important initialization made in parent JerseyTest. Try to name them differently. E.g.:

@Before
public void setUpChild() { }

@After
public void tearDownChild() { }

I came here because I was using JUnit 5 and it seems that it wasn't seeing the @Before and @After annotations on the JerseyTest setup/tearDown methods. I had to override them and use the new JUnit 5 annotations

public class MyResourceTest extends JerseyTest {
    @BeforeEach
    @Override
    public void setUp() throws Exception {
        super.setUp();
    }

    @AfterEach
    @Override
    public void tearDown() throws Exception {
        super.tearDown();
    }

    @Override
    protected Application configure() {
        return new ResourceConfig(MyResource.class);
    }

    @Test
    public void SHOULD_RETURN_BAD_REQUEST() throws IOException {
        System.out.println(target("myPath"));
        assertEquals(1, 1);
    }
}