I am facing a class cast exception, from java.lang.Double to java.lang.Integer

Question

I am writing a JUnit test case for a method that has a getValue() method which returns an Object, the getValue() returns the value I pass inside setValue() and In this case when I pass a double value to setValue() it gives a class cast exception. I am not able to figure out how to fix this.

This is the if condition I am testing,

Public class ImageToolsMemento 
{
    public static final int FREEROTATION=3;
     private double _freeRotation;
    public void combine(ImageToolsMemento obj) //test method
    {
       if(((Integer)(obj.getValue(FREEROTATION))).intValue() != 0)//line 224
            _freeRotation = ((Integer)(obj.getValue(FREEROTATION))).intValue();
    }

public Object getValue(int type)
   {
     Object ret;
     switch(type)
     {
       case FREEROTATION:

       default:
         ret = null;
     }
     return ret;
   }

public void setValue(double value, int type)
  {
    switch(type)
    {
      case FREEROTATION:
          _windowPanelMemento.setValue(value, type);
          break;
      default:
            //"default case"
            break;
    }
 }
}

Test case

public class ImageToolsMementoTest 
{
    @InjectMocks
    ImageToolsMemento imageToolsMemento;

    @Before
    public void setUp() throws Exception 
    {
        imageToolsMemento=new ImageToolsMemento();
    }

   @Test
    public void testCombine() 
    {
      imageToolsMemento.setValue(1.3, ImageToolsMemento.FREEROTATION);
      imageToolsMemento.combine(imageToolsMemento);//calling test method, line 553
      double _freeRotation=Whitebox.getInternalState(imageToolsMemento, "_freeRotation");
        assertEquals(1.3,_freeRotation,0.0);
    }
}

Stack trace

java.lang.ClassCastException: java.lang.Double cannot be cast to java.lang.Integer
    at com.toolboxmemento.ImageToolsMemento.combine(ImageToolsMemento.java:224)
    at com.toolboxmemento.test1.ImageToolsMementoTest.testCombine(ImageToolsMementoTest.java:553)

Can anyone please help me out with this problem P.S I cannot change the implementation

if you have a double with the value `10.4561` what should the integer value be? — Scary Wombat, Apr 25 '17 at 04:39
You cannot cast `Double` to `Integer`, however you can get their respective values and cast them — Courage, Apr 25 '17 at 04:40
@Oswald or [round](https://docs.oracle.com/javase/7/docs/api/java/lang/Math.html#round(float)) it — Scary Wombat, Apr 25 '17 at 04:44
In the `setValue(double value,int type)` I have to pass a double value, this double value is returned using `getValue(int type)`, in the if condition the value returned by `getValue()` is not getting casted to Integer. I think its because it returns an Object. — hushie, Apr 25 '17 at 04:51

score 0 · Answer 1 · answered Apr 25 '17 at 04:48

0

In java you cannot cast java.lang.Double to java.lang.Integer. Your error comes on line :

if(((Integer)(obj.getValue(FREEROTATION))).intValue() != 0)//line 224

Instead of cast you can use intValue method of Double class:

if(((Double)obj.getValue(FREEROTATION)).intValue() != 0)//line 224

answered Apr 25 '17 at 04:48

Jay Smith

2,331
3
16
27

Yes I know. But unfortunately I cannot change the implementation. – hushie Apr 25 '17 at 04:52

score 0 · Answer 2 · answered Apr 25 '17 at 04:50

0

You need to perform explicit typecasting because double will not stored in int type implicitly.You can do this by : int i = (int) d;

answered Apr 25 '17 at 04:50

Rajni Sharma

1

I have tried this way, but it still doesn't work. – hushie Apr 25 '17 at 05:00
The answer is bogus. int is not Integer; and double is not Double. – GhostCat Apr 25 '17 at 08:38

I am facing a class cast exception, from java.lang.Double to java.lang.Integer

2 Answers2