Junit测试异常

Question

你好，我有一个与此类似的代码，我需要为此编写junit测试，但是我不断收到nullpointeException，任何机构都可以为此编写测试吗？

 public class myState{
     @Inject
       private StateData stateData;
   public String getAbbreviation(){
       try{
           state selectedState= StateData.getSelectedState().getState();
           formatedAbbrebiation=selectedState.getStline()+""+selectedState.getRegion();

    }
     catch(Exception e){
         formatedAbbrebiation="abbrebiation not available"
    }
     return formatedAbbrebiation;
    }

这是我尝试过的：

StateData stateData=Mockito.mock(StateData.class);
Mockito.when(stateData.getSelectedState().getState()).thenReturn(selectedState)
Mockito.when(selectedState.getStLine())).thenThrow(new Exception());