Spring mvc Junit Test Null pointer Exception

[Alex Giovi]

Hi,
I'm trying to test a controller but ,I have a null Pointer exception.
This is the code:

LoginController Class:

@Autowired
public UserRepository userRepository;

HttpSession session;
@RequestMapping(value="/PersonSelect")
public String PersonSelection(ModelMap model, Principal principal ) {

    SessionInfo sessionInfo = null;             line(99)
    User user = userRepository.findByName(principal.getName()); Line(100)
    if (user != null){
        sessionInfo = new SessionInfo(user);
    } else { 
        sessionInfo = new SessionInfo(principal);
    }
    session.setAttribute("INFO", sessionInfo);

    return "PersonnSelect";     
}
---------------------------------
public class SessionInfo {

private Integer idUser;
private String userName;

public SessionInfo(Principal principal){
    if (principal != null){
        this.idUser = null;
        this.userName = principal.getName();

    }   }

    public SessionInfo(User user){
    if (user != null){

        this.idUser = user.getId();
        this.userName = user.getName();
}}

----------------------
Test class:
@RunWith(SpringJUnit4ClassRunner.class)
@WebAppConfiguration
@ContextConfiguration(locations="classpath*:/META-INF/spring1/applicationContext.xml")

 @Test
   public void SelectPerson() throws Exception{
  Principal principal = Mockito.mock(Principal.class);
   Mockito.when(principal.getName()).thenReturn("admin");  
   User user = userRepository.findByName(principal.getName());
             mockMvc.perform(MockMvcRequestBuilders.get("/PersonSelect")
            .accept(MediaType.ALL)
            .principal(principal))
            .andDo(print())
            .andExpect(MockMvcResultMatchers.status().isOk())
            }

----------------
The StackTrace:

org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.NullPointerException at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:973) at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:852) at javax.servlet.http.HttpServlet.service(HttpServlet.java:687) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837) at org.springframework.test.web.servlet.TestDispatcherServlet.service(TestDispatcherServlet.java:62) at javax.servlet.http.HttpServlet.service(HttpServlet.java:790) at org.springframework.mock.web.MockFilterChain$ServletFilterProxy.doFilter(MockFilterChain.java:170) at org.springframework.mock.web.MockFilterChain.doFilter(MockFilterChain.java:137) at org.springframework.test.web.servlet.MockMvc.perform(MockMvc.java:141) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44) at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17) at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26) at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:74) at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:83) at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:72) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:233) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:87) at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236) at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229) at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61) at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:71) at org.junit.runners.ParentRunner.run(ParentRunner.java:309) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:176) at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50) at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197) Caused by: java.lang.NullPointerException at com.webStore.controllers.LoginController.PersonSelection(LoginController.java:100) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:215) at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132) at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:749) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:689) at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:938) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:870) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961) ... 38 more
--------------------
The problem that my user Entity is not null , it return a entity, so i don't understand why i still have this error. Is my approch to have the Principal Role correct?If not, how can i inject the Principal role in my test.
Appreciate any help.
Many thanks