I have implemented my validation for list of custom class as mention in this post. For reference here my code looks like
class TopDtoForm {
#NotEmpty
private String topVar;
private List<DownDto> downVarList;
//getter and setter
}
class DownDto {
private Long id;
private String name;
//getter and setter
}
#Component
public class TopDtoFormValidator implements Validator {
#Override
public boolean supports(Class<?> clazz) {
return TopDtoForm.class.equals(clazz);
}
#Override
public void validate(Object target, Errors errors) {
TopDtoForm topDtoForm = (TopDtoForm) target;
for(int index=0; index<topDtoForm.getDownVarList().size(); index++) {
DownDto downDto = topDtoForm.getDownVarList().get(index);
if(downDto.getName().isEmpty()) {
errors.rejectValue("downVarList[" + index + "].name", "name.empty");
}
}
}
}
So even I send empty name binding result has 0 error. I tested with topVar and it is working fine. My question is do I have to do any other configuration to say use this validator?
Thanks
In Spring MVC just annotate in TopDtoForm your list with #Valid and add #NotEmpty to DownDto. Spring will validate it just fine:
class TopDtoForm {
#NotEmpty
private String topVar;
#Valid
private List<DownDto> downVarList;
//getter and setter
}
class DownDto {
private Long id;
#NotEmpty
private String name;
//getter and setter
}
Then in RequestMapping just:
#RequestMapping(value = "/submitForm.htm", method = RequestMethod.POST) public #ResponseBody String saveForm(#Valid #ModelAttribute("topDtoForm") TopDtoForm topDtoForm, BindingResult result) {}
Also consider switching from #NotEmpty to #NotBlank as is also checks for white characters (space, tabs etc.)
Related
In my spring boot project, I noticed a strange Jackson behavior. I searched over internet, found out what to do, but haven't found out why.
UserDto:
#Setter
#Getter
#AllArgsConstructor
public class UserDto {
private String username;
private String email;
private String password;
private String name;
private String surname;
private UserStatus status;
private byte[] avatar;
private ZonedDateTime created_at;
}
Adding a new user works just fine.
TagDto:
#Setter
#Getter
#AllArgsConstructor
public class TagDto {
private String tag;
}
Trying to add a new tag ends with an error:
com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot construct instance of TagDto (although at least one Creator exists): cannot deserialize from Object value (no delegate- or property-based Creator)
The solution to the problem was to add zero-arg constructor to the TagDto class.
Why does Jackson require no-arg constructor for deserialization in TagDto, while working just fine with UserDto?
Used same method for adding both.
My Tag and User entities are both annotated with
#Entity
#Setter
#Getter
#NoArgsConstructor
and have all args constructors:
#Entity
#Setter
#Getter
#NoArgsConstructor
public class User extends AbstractModel {
private String username;
private String password;
private String email;
private String name;
private String surname;
private UserStatus status;
#Lob
private byte[] avatar;
#Setter(AccessLevel.NONE)
private ZonedDateTime created_at;
public User(final String username, final String password, final String email, final String name, final String surname) {
this.username = username;
this.password = password;
this.email = email;
this.name = name;
this.surname = surname;
this.created_at = ZonedDateTime.now();
}
}
#Entity
#Setter
#Getter
#NoArgsConstructor
#AllArgsConstructor
public class Tag extends AbstractModel {
private String tag;
}
#MappedSuperclass
#Getter
public abstract class AbstractModel {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Integer id;
}
Entity generation:
#PostMapping(path = "/add")
public ResponseEntity<String> add(#Valid #RequestBody final D dto) {
this.abstractModelService.add(dto);
return new ResponseEntity<>("Success", HttpStatus.CREATED);
}
public void add(final D dto) {
//CRUD repository save method
this.modelRepositoryInterface.save(this.getModelFromDto(dto));
}
#Override
protected Tag getModelFromDto(final TagDto tagDto) {
return new Tag(tagDto.getTag());
}
#Override
protected User getModelFromDto(final UserDto userDto) {
return new User(userDto.getUsername(), userDto.getPassword(), userDto.getEmail(), userDto.getName(), userDto.getSurname());
}
Error occurs when parsing JSON
{"tag":"example"}
sent via postman localhost:8081/tag/add, returns
{
"timestamp": "2020-09-26T18:50:39.974+00:00",
"status": 400,
"error": "Bad Request",
"message": "",
"path": "/tag/add"
}
I am using Lombok v1.18.12 and Spring boot 2.3.3.RELEASE with Jackson v2.11.2.
TL;DR: Solution is at the end.
Jackson supports multiple ways of creating POJOs. The following lists the most common ways, but it likely not a complete list:
Create instance using no-arg constructor, then call setter methods to assign property values.
public class Foo {
private int id;
public int getId() { return this.id; }
#JsonProperty
public void setId(int id) { this.id = id; }
}
Specifying #JsonProperty is optional, but can be used to fine-tune the mappings, together with annotations like #JsonIgnore, #JsonAnyGetter, ...
Create instance using constructor with arguments.
public class Foo {
private int id;
#JsonCreator
public Foo(#JsonProperty("id") int id) {
this.id = id;
}
public int getId() {
return this.id;
}
}
Specifying #JsonCreator for the constructor is optional, but I believe it is required if there is more than one constructor. Specifying #JsonProperty for the parameters is optional, but is required for naming the properties if the parameter names are not included in the class file (-parameters compiler option).
The parameters imply that the properties are required. Optional properties can be set using setter methods.
Create instance using factory method.
public class Foo {
private int id;
#JsonCreator
public static Foo create(#JsonProperty("id") int id) {
return new Foo(id);
}
private Foo(int id) {
this.id = id;
}
public int getId() {
return this.id;
}
}
Create instance from text value using String constructor.
public class Foo {
private int id;
#JsonCreator
public Foo(String str) {
this.id = Integer.parseInt(id);
}
public int getId() {
return this.id;
}
#JsonValue
public String asJsonValue() {
return Integer.toString(this.id);
}
}
This is useful when a the POJO has a simply text representation, e.g. a LocalDate is a POJO with 3 properties (year, month, dayOfMonth), but is generally best serialized as a single string (yyyy-MM-dd format). #JsonValue identifies the method to be used during serialization, and #JsonCreator identifies the constructor/factory-method to be used during deserialization.
Note: This can also be used for single-value construction using JSON values other than String, but that is very rare.
Ok, that was the background information. What is happening for the examples in the question, it that UserDto works because there is only one constructor (so #JsonCreator is not needed), and many arguments (so #JsonProperty is not needed).
However, for TagDto there is only a single-argument constructor without any annotations, so Jackson classifies that constructor as a type #4 (from my list above), not a type #2.
Which means that it is expecting the POJO to be a value-class, where the JSON for the enclosing object would be { ..., "tag": "value", ... }, not { ..., "tag": {"tag": "example"}, ... }.
To resolve the issue, you need to tell Jackson that the constructor is a property initializing constructor (#2), not a value-type constructor (#4), by specifying #JsonProperty on the constructor argument.
This means that you cannot have Lombok create the constructor for you:
#Setter
#Getter
public class TagDto {
private String tag;
public TagDto(#JsonProperty("tag") String tag) {
this.tag = tag;
}
}
#JsonCreator not deserialising #RequestParam of type enum
I am working on a Spring application where the controller is receiving list of request params that Spring is binding to a wrapper object. One of the params is of type enum where I am receiving it by some property name.
Endpoint example: http://localhost:8080/searchCustomers?lastName=Smith&country=Netherlands
#RequestMapping(value = "/search/customers", method = RequestMethod.GET)
public CustomerList searchCustomers(#Valid CustomerSearchCriteria searchCriteria)
public class CustomerSearchCriteria {
private String lastName;
private Country country;
}
public enum Country {
GB("United Kingdom"),
NL("Netherlands")
private String countryName;
Country(String countryName) {
countryName = countryName;
}
#JsonCreator
public static Country fromCountryName(String countryName) {
for(Country country : Country.values()) {
if(country.getCountryName().equalsIgnoreCase(countryName)) {
return country;
}
}
return null;
}
#JsonValue
public String toCountryName() {
return countryName;
}
}
I am expecting Spring to bind enum Country.Netherlands to CustomerSearchCriteria.country but its not doing it so. I tried similar annotations with #RequestBody and that works fine, so I am guessing he Spring binding is ignoring #JsonCreator.
Any helpful tips would be appreciated.
Here is the code that is behind #Mithat Konuk comment.
Put in your controller something like:
import java.beans.PropertyEditorSupport;
#RestController
public class CountryController {
// your controller methods
// ...
public class CountryConverter extends PropertyEditorSupport {
public void setAsText(final String text) throws IllegalArgumentException {
setValue(Country.fromCountryName(text));
}
}
#InitBinder
public void initBinder(final WebDataBinder webdataBinder) {
webdataBinder.registerCustomEditor(Country.class, new CountryConverter());
}
}
More information ca be found here: https://www.devglan.com/spring-boot/enums-as-request-parameters-in-spring-boot-rest.
I want to load any property files in spring POJO classes.
Actually, I want to use any properties from property file in #Size, #NotNull or any validation annotations in spring model classes.
But the issue is that #Size, #NotNull etc annotation are invoked at compile-time whereas any property file's data are invoked at runtime.
Even, I want to use in the max parameter of #Size which accepts the only constant integer. How can I load value and cast it to Integer as a constant value?
And I can use custom validator or any custom annotation to solve the issue but as per the organization policy, I can't use much customization.
I found an additional solution to this problem that we can use a class of constants instead of the property file.
I can use this constants file anywhere in my workspace whereas property file can't use at Size.max property of the model validation
CommonConstants.java
public class CommonConstants
{
public static final int NAME=4;
public static final int ROLE=2;
}
Employee.java
private int id;
#Size(max = CommonConstants.NAME, message = "length exceeds : name")
private String name;
#Size(max = CommonConstants.ROLE, message = "length exceeds : role")
private String role;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getRole() {
return role;
}
public void setRole(String role) {
this.role = role;
}
EmployeeController.java
#Controller
public class EmployeeController {
private static final Logger logger = LoggerFactory.getLogger(EmployeeController.class);
private Map<Integer, Employee> emps = null;
public EmployeeController() {
emps = new HashMap<Integer, Employee>();
}
#RequestMapping(value = "/emp/save.do", method = RequestMethod.POST)
public String saveEmployeeAction(#Valid Employee employee, BindingResult bindingResult, Model model)
{
if (bindingResult.hasErrors()) {
logger.info("Returning empSave.jsp page");
return "empSave";
}
logger.info("Returning empSaveSuccess.jsp page");
model.addAttribute("emp", employee);
emps.put(employee.getId(), employee);
return "empSaveSuccess";
}
}
Output
I am using an implementation of an interface in Java.
For eg: There can be many PaymentTypes like Credit Card, Mobile etc.
I am making a REST API which contains an interface- how do I map this in JAXB, currently it gives me JAXBException occurred : 2 counts of IllegalAnnotationExceptions.
Currently I am using Apache-CXF and JAXb
#XmlRootElement
public class Payment {
#XmlElement
private PaymentType paymentType;
#XmlElement
private long price;
public Payment() {
}
public Payment(final PaymentType paymentType, final long price) {
super();
this.paymentType = paymentType;
this.price = price;
}
}
#Path("/trial")
public class TrialService {
#GET
#Produces(MediaType.APPLICATION_JSON)
public List<Payment> getPayments() {
final List<Payment> payments = new LinkedList<Payment>();
final CreditCardDetails creditCard = new CreditCardDetails(
"8767798778", "123", 12, 2016);
final Payment payment = new Payment(creditCard, 10);
payments.add(payment);
return payments;
}
#POST
#Consumes(MediaType.APPLICATION_JSON)
#Produces(MediaType.APPLICATION_JSON)
public PaymentDetails startPayment(final PaymentDetails paymentDetails) {
return paymentDetails;
}
}
public class CreditCardDetails implements PaymentType {
#XmlElement
private String creditCardNumber;
#XmlElement
private String cvv;
#XmlElement
private int expirationMonth;
#XmlElement
private int expirationYear;
public CreditCardDetails() {
}
#SuppressWarnings("javadoc")
public CreditCardDetails(
// final BillingAddress billingAddress,
final String creditCardNumber, final String cvv,
final int expirationMonth, final int expirationYear) {
super();
this.creditCardNumber = creditCardNumber;
this.cvv = cvv;
setExpirationMonth(expirationMonth);
setExpirationYear(expirationYear);
}
}
How should I be mapping this or should I be using an entirely different approach?
Edits:
For the POST method I am receiving a payment. Payment could contain any object CreditCard, Wallet etc. What annotation should I provide so that it is desirialized correctly.
Currently it throws a JAXB exception.
The full error message which you've got is:
Caused by: com.sun.xml.bind.v2.runtime.IllegalAnnotationsException: 2 counts of IllegalAnnotationExceptions PaymentType is an interface, and JAXB can't handle interfaces.
You need to use concreate class for your elements or point it in type attribute of #XmlElement annotation:
#XmlElement(type = CreditCardDetails.class)
private PaymentType paymentType;
If you have more classes that uses PaymentType interface then you may use the following solution:
#XmlAnyElement
#XmlElementRefs({
#XmlElementRef(type=CreditCardDetails.class),
#XmlElementRef(type=Wallet.class)
})
PaymentType paymentType;
The list of #XmlElementRefs can have any number of elements but all possibilities must be listed. CreditCardDetails and Wallet must be annotated with #XmlRootElement.
You can skip #XmlElementRefs annotation:
#XmlAnyElement(lax=true)
PaymentType paymentType;
but in that case make sure you have any required class in JAXB context, if you do not use registry annotate your class with PaymentType field with #XmlSeeAlso({CreditCardDetails.class, Wallet.class}).
I'm using BoilerPlateGeneration of GWTP. You can find info of what is it here:
Boilerplate Generation
I want to keep javax.validation annotations, but when the code is generated, they are not in.
This is an example of what i want:
#GenDispatch (isSecure = false)
public class AnExample {
#NotNull
#In(value = 1)
private String name;
}
The result code that I get:
public class AnExampleAction implements Action<AnExampleResult> {
private java.lang.String name;
// .....Constructors, getters, etc......
}
I want this:
public class AnExampleAction implements Action<AnExampleResult> {
#NotNull
private java.lang.String name;
// .....Constructors, getters, etc......
}
As you can see, I want to keep #NotNull annotation.
Thank you.