Spring Unit testing rest controller error

Question

This is my UserController, get() method which returns all UserDto's.

@GetMapping("/")
public List<UserDto> get() {
    return userService.getUsers().stream().map((User user) -> toUserDto(user)).collect(Collectors.toList());
}

And, this is my UserControllerTest testing this get() method which fails. Could you tell me what I'm doing wrong? I'm making first steps with testing.

This is the console log:

java.lang.NullPointerException
at pl.rmitula.restfullshop.controller.UserControllerTest.getAll(UserControllerTest.java:43)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:389)
at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:115)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$6(TestMethodTestDescriptor.java:167)
at org.junit.jupiter.engine.execution.ThrowableCollector.execute(ThrowableCollector.java:40)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:163)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:110)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:57)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.lambda$execute$3(HierarchicalTestExecutor.java:83)
at org.junit.platform.engine.support.hierarchical.SingleTestExecutor.executeSafely(SingleTestExecutor.java:66)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:77)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.lambda$null$2(HierarchicalTestExecutor.java:92)
at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:184)
at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:175)
at java.util.Iterator.forEachRemaining(Iterator.java:116)
at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:151)
at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:174)
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:418)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.lambda$execute$3(HierarchicalTestExecutor.java:92)
at org.junit.platform.engine.support.hierarchical.SingleTestExecutor.executeSafely(SingleTestExecutor.java:66)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:77)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.lambda$null$2(HierarchicalTestExecutor.java:92)
at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:184)
at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:175)
at java.util.Iterator.forEachRemaining(Iterator.java:116)
at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:151)
at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:174)
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:418)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.lambda$execute$3(HierarchicalTestExecutor.java:92)
at org.junit.platform.engine.support.hierarchical.SingleTestExecutor.executeSafely(SingleTestExecutor.java:66)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:77)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:51)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:43)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:170)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:154)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:90)
at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:62)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

youe need to mock your userService

pvpkiran
– pvpkiran

2018-02-21 10:26:02 +00:00
Commented Feb 21, 2018 at 10:26 — pvpkiran
– pvpkiran, Commented Feb 21, 2018 at 10:26
@pvpkiran Could you show me an example?

user3361149
– user3361149

2018-02-21 10:50:07 +00:00
Commented Feb 21, 2018 at 10:50 — user3361149
– user3361149, Commented Feb 21, 2018 at 10:50

Darren Forsythe · Accepted Answer · 2018-02-21 11:49:08Z

1

You are not mocking the required service.

You need a mock of userService to be injected into your controller, and mocked response if required.

@RunWith(MockitoJUnitRunner.class)
class UserControllerTest {

@Mock
private UserService userService;


@InjectMocks
private UserController userController;

private MockMvc mockMvc;

@Before
void setUp() {
    mockMvc = MockMvcBuilders.standaloneSetup(this.userController).build();
}

@Test
void getAll() throws Exception {
    List<UserDto> userdtos = Arrays.asList(
            new UserDto((long) 1, "John", "Snow", "[email protected]", "snow", "password"),
            new UserDto((long) 2, "Tyrion", "Lanister", "[email protected]", "tyrion", "password"));

    String url = "/api/users";
    MvcResult mvcResult = mockMvc.perform(get(url)).andExpect(MockMvcResultMatchers.status().isOk()).andReturn();

    Assert.assertEquals("failure", mvcResult.getResponse(), userdtos);

}

}

I'm not a big fan of the standalone approach and find the WebMvcTest slice test cleaner which effectively does the setup for you.

@RunWith(SpringRunner.class)
@WebMvcTest
    class UserControllerTest {

    @MockBean
    private UserService userService;


    @Autowired
    private MockMvc mockMvc;

//tests
}

answered Feb 21, 2018 at 11:49

Darren Forsythe

11.5k4 gold badges47 silver badges57 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

user3361149 Over a year ago

Ok, but both of this examples still don't work for me. I got same NullPointerException with this code . Could you check this?

Darren Forsythe Over a year ago

add your full controller too

Darren Forsythe Over a year ago

and are you actually mocking some sort of collection, even if empty, to return for the stream? Null will be the default.

Collectives™ on Stack Overflow

Spring Unit testing rest controller error

1 Answer 1

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related