JUnit test for website contains one string or (exclusive) other string

In a spring-mvc project I have a test for the content of the index/homepage:

@RunWith(SpringRunner.class)
@SpringBootTest
@AutoConfigureMockMvc
public class HomePageTest {

    @Autowired
    private MockMvc mockMvc;

    @Test
    public void shouldContainStrings() throws Exception {
        this.mockMvc.perform(get("/")).andDo(print()).andExpect(status().isOk())
            .andExpect(content().string(containsString("Hello World")));
    }
}

This test works fine so far. But now I would like to test for the occurrence of the strings "Login" or (excl) "Logout", i.e. I want to test whether exactly one (not zero and not both) of these two strings appears in the content. How can I match this or condition?