Cannot instantiate @InjectMocks field named exception with java class

Question

I have a class with user defined constructor. ``` public class Employee { @Inject private MyBean myBean; private String abcd; protected Employee(Parameter1 param1, Parameter2 param2) { //some operations on method params //some operation on mybean this.abcd = "some value"; } protected String getAbcd() { return nrOfAccesses; } protected void setAbcd(String abcd) { this.abcd = abcd; } } ``` Test class ``` @RunWith(MockitoJUnitRunner.class) public class TestEmployee { @Mock private MyBean myBean; private Parameter1 param1; private Parameter2 param2; @InjectMocks private Employee employee; @Before public void prepare() throws Exception { //some intialization param1 = some value; param2 = some value; when(myBean.get(eq("ID"))).thenReturn("1075"); } @Test public void testEmployeeID() { employee = new Employee(param1, param2); assertThat(employee.getAbcd(), is("XYZC")); } ``` I am getting exception as ``` org.mockito.exceptions.base.MockitoException: Cannot instantiate @InjectMocks field name…

Accepted Answer

if you do a `employee = new Employee(param1, param2);` you may as well skip `@InjectMocks`.

It is supposed to do the following:

```
@InjectMocks
ClassUnderTest cut;

@Mock
Dependency1 dep1;
@Mock
Dependency2 dep2;

@Before
public void setup() {
  initMocks(this);
}
```

omitting `@InjectMocks` the same behaviour can be achieved with the following code:

```
ClassUnderTest cut;

@Mock
Dependency1 dep1;
@Mock
Dependency2 dep2;

@Before
public void setup() {
  initMocks(this);
  cut = new ClassUnderTest(dep1, dep2);
}
```

In your specific case, you should mock `param1` and `param2`. Never call the constructor manually when using `@InjectMocks`.

Cannot instantiate @InjectMocks field named exception with java class

Solution

Problem