java.lang.IllegalArgumentException: No DataSource specified Junit and Mockito

Question

Good Morning people! I am doing unit test in my spring boot application but it launches the next exception: java.lang.IllegalArgumentException: No DataSource specified;

This is my method:

@RestController
public class controlador {

@Autowired(required = true)
JdbcTemplate conn;

@CrossOrigin
@RequestMapping(value = "/getlistadopantallatab", method = RequestMethod.POST, consumes="application/json",produces = "application/json")
@ResponseBody
public Map<String, Object> getListadoPantallaTab(@RequestBody Map<String,Object> dto) {
    Map<String, Object> simpleJdbcCallResult = null;
    try {
        SimpleJdbcCall simpleJdbcCall = new SimpleJdbcCall(conn)
                .withCatalogName("CCR_PACKAGE")
                .withProcedureName("getListadoPorPantallaTab");

        SqlParameterSource in = new MapSqlParameterSource(dto);
        simpleJdbcCallResult = simpleJdbcCall.execute(in);
    } catch (Exception e) {
        System.out.println("Se ha lanzado la siguiente excepcion: " + e);
    }
    return simpleJdbcCallResult;
}

and it is my test:

public class controladorTest {

static controlador mockInstanced;

@BeforeClass
public static void setup() throws Exception {
    mockInstanced= new controlador();
    mockInstanced.conn = mock(JdbcTemplate.class);
}

/**
 * Test of getListadoPantallaTab method, of class controlador.
 */
@Test
public void testGetListadoPantallaTab() {
    System.out.println("Test unitario getListadoPantallaTab: ");
    @SuppressWarnings("serial")
    Map<String, Object> dto = new HashMap<String, Object>() {{
        put("Inicio", 1);
        put("fin", 15);
    }};

    mockInstanced.getListadoPantallaTab(dto);
}

Somebody knows what i am doing wrong?

PD: Sorry for my english, i am spanish!

Answer 1

You are trying to test a class, which uses beans without starting the Spring's application context.

There are multiple ways to solve your problem.

1. Make spring to run application context. You can do that by adding: @SpringBootTest and @RunWith(SpringRunner.class) annotations to your test class. Something like this:

@SpringBootTest
@RunWith(SpringRunner.class)
public class controladorTest {
...
}

This way the Spring application context will be created - but you don't have to mock your controller instance - as it's already created - so you can just autowire it:

@SpringBootTest
@RunWith(SpringRunner.class)
public class controladorTest {
    @Autowired
    private controlador controlador;
...
}

and remove next lines :

static controlador mockInstanced;

@BeforeClass
public static void setup() throws Exception {
    mockInstanced= new controlador();
    mockInstanced.conn = mock(JdbcTemplate.class);
}

2. Another theoretical way is to mock JdbcTemplate and inject it into your mock using @InjectMocks - but I wouldn't recommend to do it - too cumbersome and fragile solution.
3. Also, taking into account, that your controller uses only JdbcTemplate as a dependency, you can use an embedded DB for Junit and create the JdbcTemplate manually and inject it to your controller - in this case, there is no need to create the application context and you can just manually create a controller instance and pass JdbcTemplate to it. See this for more info

So after step 1, your code should look like the following:

@SpringBootTest
@RunWith(SpringRunner.class)
public class controladorTest {

    @Autowired
    private controlador controlador;

    /**
     * Test of getListadoPantallaTab method, of class controlador.
     */
    @Test
    public void testGetListadoPantallaTab() {
        System.out.println("Test unitario getListadoPantallaTab: ");
        @SuppressWarnings("serial")
        Map<String, Object> dto = new HashMap<String, Object>() {{
            put("Inicio", 1);
            put("fin", 15);
        }};

        controlador.getListadoPantallaTab(dto);
    }
}

By the way, please look at Java naming conventions - to make your code more readable.

More info about testing with spring here