JasperException: java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'user' available as request attribute - spring

Question

I have two Data Model : User and Car, User can have many cars , so this is the User Class :
#Entity
#Table(name="APP_USER")
public class User implements Serializable{
#Id #GeneratedValue(strategy=GenerationType.IDENTITY)
private Integer id;
......
#OneToMany(mappedBy="user",cascade=CascadeType.ALL)
private Set<Car> cars = new HashSet<Car>();
Car.java :
#Entity
public class Car implements Serializable {
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
private int id ;
.....
#ManyToOne(optional=false)
#JoinColumn(name="user_fk")
private User user;
In the carController , I have the method to add a new Car for one user :
#Controller
#RequestMapping("/cars")
public class CarController {
#Autowired
CarService carService;
#Autowired
UserService userService;
#RequestMapping(value={"/list"},method=RequestMethod.GET)
public String listCars(ModelMap model){
List<Car> cars = carService.allCars();
model.addAttribute("cars", cars);
return "car"; }
#ModelAttribute("utilisateurs")
public List<User> allUsers(){
List<User> utilisateurs = userService.findAllUsers();
return utilisateurs;
}
#RequestMapping(value={"/newCar"},method=RequestMethod.GET)
public String newCar(ModelMap model){
Car car = new Car();
model.addAttribute("car",car);
return "carRegistration";
}
#RequestMapping(value={"newCar"},method=RequestMethod.POST)
public String newCar(#Valid Car car, BindingResult result,ModelMap model){
if (result.hasErrors()) {
return "registration";
}
carService.save(car);
model.addAttribute("car",car);
return "redirect:/cars/list";
}
Finally , in the view , the form is :
<form:form method="POST" modelAttribute="car"
class="form-horizontal">
<form:input type="hidden" path="id" id="id" />
<div class="control-group">
<label class="control-label">Libelle</label>
<div class="controls">
<form:input type="text" path="libelle" id="libelle" style="height:4%" />
</div>
</div>
<div class="control-group">
<label class="control-label">Registration</label>
<div class="controls">
<form:input type="text" path="registration" id="email" />
</div>
</div>
<div class="control-group">
<label class="control-label">Utilisateur</label>
<div class="controls">
<form:select path="user" items="${utilisateurs}" itemValue="id" itemLabel="lastName" style="margin-left: 4%;"></form:select>
</div>
</div>
<div class="form-actions">
<input type="submit" value="Validate" class="btn btn-success" />
</div>
</form:form>
I can get the view , but when I click on button submit , I get this error :
Neither BindingResult nor plain target object for bean name 'user' available as request attribute.
I think there is a problem with the select item of users !!

Answer 1

Have you provided any Spring converter or formatter for User ?
applicationContext.xml:
<bean id="conversionService"
class="org.springframework.context.support.ConversionServiceFactoryBean">
<property name="converters">
<list>
<bean class="my.project.StringToUser"/>
<bean class="my.project.StringToRole"/>
</list>
</property>
</bean>
<mvc:annotation-driven conversion-service="conversionService" />
It will convert User id to User object.
my.project.StringToUser:
import org.springframework.core.convert.converter.Converter;
public class StringToUser implements Converter<String, JUser> {
#Autowired
private UserService userService;
#Override
public JUser convert(String source) {
long id = Long.valueOf(source);
return userService.get(id);
}
}
the error :
WARNING: Failed to bind request element: org.springframework.beans.TypeMismatchException:
Failed to convert value of type [com.websystique.springmvc.model.User] to required type [com.websystique.springmvc.model.User];
nested exception is org.springframework.core.convert.ConversionFailedException:
Failed to convert from type [com.websystique.springmvc.model.User] to
type [#org.springframework.web.bind.annotation.ModelAttribute #javax.validation.Valid com.websystique.springmvc.model.User]
for value 'User [id=null, ssoId=alaa, password=alaa1991, firstName=, lastName=, email=, userProfiles=null, accounts=null, userDocuments=[], cars=[], documents=[]]';
nested exception is java.lang.ClassCastException:
com.websystique.springmvc.model.User cannot be cast to java.lang.String