I have a REST Webservice, I get my data from a JSON request:
#POST
#Path("load")
#Consumes(MediaType.APPLICATION_JSON)
#Produces(MediaType.APPLICATION_JSON)
#RequestMapping(value="load", method = RequestMethod.POST, produces = MediaType.APPLICATION_JSON, consumes = MediaType.APPLICATION_JSON)
public #ResponseBody
Respuesta loadData(#RequestBody Persons person) {
//code
em.persist(person);
}
This is my Person class:
#Entity
#Table(name = "myparenttable", schema = "myschema", catalog = "mydb")
public class Parent {
private Integer id_parent;
private String name;
private String last_name;
private String username;
//getters and setters
public Parent(){}
}
I want to generate the username member with parts of the name and last_name members; for simplicity, lets say I need the username be = name + last_name; the username member is not specified in the json request, is there a way to load a member with values of other members in the object initialization? in this case, automatic initialization with #RequestMapping and #RequestBody
I want to return an error when the body of a REST request is empty (e.g contains only {}) but there is no way to detect if the request body contains an empty JSON or not.
I tried to change #RequestBody(required = true) but it's not working.
#PatchMapping("{id}")
public ResponseEntity<Book> updateAdvisor(#PathVariable("id") Integer id,
#Valid #RequestBody BookDto newBook) {
Book addedBook = bookService.updateBook(newBook);
return new ResponseEntity<>(addedBook,HttpStatus.OK);
}
If the body sent contains an empty JSON I should return an exception.
If the body is not empty and at least one element is provided I won't return an error.
Try #RequestBody(required = false)
This should cause the newBook parameter to be null when there is no request body.
The above still stands and is the answer to the original question.
To solve the newly edited question:
Change the #RequestBody BookDto newBook parameter to a String parameter
(for example, #RequestBody String newBookJson).
Perform pre-conversion validation (such as, "is the body an empty JSON string value").
If the body contains valid JSON,
parse the JSON into to an object (example below).
#Autowired
private ObjectMapper objectMapper; // A Jackson ObjectMapper.
#PatchMapping("{id}")
public ResponseEntity<Book> updateAdvisor(
#PathVariable("id") Integer id,
#Valid #RequestBody String newBookJson)
{
if (isGoodStuff(newBookJson)) // You must write this method.
{
final BookDto newBook = ObjectMapper.readValue(newBookJson, BookDto.class);
... do stuff.
}
else // newBookJson is not good
{
.. do error handling stuff.
}
}
Let's suppose you have a Class BookDto :
public class BookDto {
private String bookName;
private String authorName;
}
We can use #ScriptAssert Annotation on Class BookDto:
#ScriptAssert(lang = "javascript", script = "_this.bookName != null || _this.authorName != null")
public class BookDto {
private String bookName;
private String authorName;
}
then in the resource/controller Class:
#PatchMapping("{id}")
public ResponseEntity<Book> updateAdvisor(#PathVariable("id") Integer id,
#Valid #RequestBody BookDto newBook) {
Book addedBook = bookService.updateBook(newBook);
return new ResponseEntity<>(addedBook,HttpStatus.OK);
}
Now #Valid annotation will validate whatever we have asserted in the #ScriptAssert annotation's script attribute. i.e it now checks if the body of a REST request is empty (e.g contains only {}).
I am using spring-boot-1.5.6 and modelmapper-1.1.0. I would like to map the entity object to OrderDto
but don't know how to do it via modelMapper. Please find the below code
Order.Java
public class Order {
private String orderUid;
private Invoice invoice;
private List<Item> items;
//Getter & setter
}
Item.java
public class Item {
private String itemId;
private String itemName;
private String itemUid;
private String isbn;
//other details of item
//Getter & setter
}
OrderDTO.java
public class OrderDTO {
private String orderUid;
private Invoice invoice;
private String itemId;
private String itemName;
private String itemUid;
private String isbn;
//other details of item
//Getter & setter
}
I would like to return OrderDTO with the item based on the itemID we are getting from the client(FrontEnd)
public Page<OrderDTO> convertOrderEntityToDTO (Page<Order> orderList,String itemId) {
ModelMapper modelMapper = new ModelMapper();
Type listType = new TypeToken<Page<OrderDTO>>() {}.getType();
modelMapper.addConverter((MappingContext<Order, OrderDTO> context) -> {
Item item = context.getSource().getItems().stream()
.filter(item -> equalsIgnoreCase(item.getItemId,itemId))
.findAny().orElse(null);
if (item != null) {
OrderDTO orderDTO = context.getDestination();
orderDTO.setItemId(item.getItemId());
orderDTO.setItemName(item.getItemName());
orderDTO.setItemUid(item.getItemUid());
orderDTO.setIsbn(item.getIsbn());
return orderDTO;
}
return null;
});
Page<OrderDTO> addonServices = modelMapper.map(orderList, listType);
}
In the above method, converter was never called(may be because of incorrect TypePair of modelMapper) and the item related attributes
in OrderDTO is always null. I would like to get the Item value based on ItemId.
Any help or hint would be appreciable. Any suggestion with or without modelMapper would be really appreciable.
As far as I understand, you use Page class of org.springframework.data or something like that. Anyway, this generic Page class contains generic List with your data. I would say, that this construction is just "too generic" for modelMapper. You'd better get list of your data, convert it and create a new Page.
Furthermore
You should create a typeMap to register a new converter
context.getDestination() returns not null if you provide new destination object by modelMapper.map(..). In your case you'll get null.
This is my vision of your convertOrderEntityToDTO method:
public Page<OrderDTO> convertOrderEntityToDTO(Page<Order> orderList, String itemId) {
ModelMapper modelMapper = new ModelMapper();
modelMapper.createTypeMap(Order.class, OrderDTO.class)
.setConverter(context -> context.getSource().getItems().stream()
.filter(o -> equalsIgnoreCase(o.getItemId(), itemId))
.findAny().map(o -> {
OrderDTO orderDTO = new OrderDTO();
orderDTO.setItemId(o.getItemId());
orderDTO.setItemName(o.getItemName());
orderDTO.setItemUid(o.getItemUid());
orderDTO.setIsbn(o.getIsbn());
return orderDTO;
}).orElse(null));
List<OrderDTO> orderDtoList = orderList.getContent().stream()
.map(o -> modelMapper.map(o, OrderDTO.class))
.collect(Collectors.toList());
return new PageImpl<>(orderDtoList, orderList.getPageable(), orderList.getTotalElements());
}
If you are using Spring Data JpaRepositories to retrieve data from the database you can make a repository method that creates a DTO for you. Such a method would look something like this:
#Query("SELECT new full.path.OrderDTO(s.itemId, s.itemName, s.itemUid) FROM Item s WHERE s.itemId = :id")
public OrderDTO getOrderDTOByItemId(#Param("id") long id);
The method should go in the jparepository class you use to retrieve Item instances from the database with. To make this work your OrderDTO needs to have a constructor with this parameter list. ( long itemId, String itemName, String itemUid). The parameters need to be in the same order as (s.itemId, s.itemName, s.itemUid). Also always make sure you create a default constructor as well when you create a constructor with parameters.
I'm trying to distinguish between null values and not provided values when partially updating an entity with PUT request method in Spring Rest Controller.
Consider the following entity, as an example:
#Entity
private class Person {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
/* let's assume the following attributes may be null */
private String firstName;
private String lastName;
/* getters and setters ... */
}
My Person repository (Spring Data):
#Repository
public interface PersonRepository extends CrudRepository<Person, Long> {
}
The DTO I use:
private class PersonDTO {
private String firstName;
private String lastName;
/* getters and setters ... */
}
My Spring RestController:
#RestController
#RequestMapping("/api/people")
public class PersonController {
#Autowired
private PersonRepository people;
#Transactional
#RequestMapping(path = "/{personId}", method = RequestMethod.PUT)
public ResponseEntity<?> update(
#PathVariable String personId,
#RequestBody PersonDTO dto) {
// get the entity by ID
Person p = people.findOne(personId); // we assume it exists
// update ONLY entity attributes that have been defined
if(/* dto.getFirstName is defined */)
p.setFirstName = dto.getFirstName;
if(/* dto.getLastName is defined */)
p.setLastName = dto.getLastName;
return ResponseEntity.ok(p);
}
}
Request with missing property
{"firstName": "John"}
Expected behaviour: update firstName= "John" (leave lastName unchanged).
Request with null property
{"firstName": "John", "lastName": null}
Expected behaviour: update firstName="John" and set lastName=null.
I cannot distinguish between these two cases, sincelastName in the DTO is always set to null by Jackson.
Note:
I know that REST best practices (RFC 6902) recommend using PATCH instead of PUT for partial updates, but in my particular scenario I need to use PUT.
Another option is to use java.util.Optional.
import com.fasterxml.jackson.annotation.JsonInclude;
import java.util.Optional;
#JsonInclude(JsonInclude.Include.NON_NULL)
private class PersonDTO {
private Optional<String> firstName;
private Optional<String> lastName;
/* getters and setters ... */
}
If firstName is not set, the value is null, and would be ignored by the #JsonInclude annotation. Otherwise, if implicitly set in the request object, firstName would not be null, but firstName.get() would be. I found this browsing the solution #laffuste linked to a little lower down in a different comment (garretwilson's initial comment saying it didn't work turns out to work).
You can also map the DTO to the Entity with Jackson's ObjectMapper, and it will ignore properties that were not passed in the request object:
import com.fasterxml.jackson.databind.ObjectMapper;
class PersonController {
// ...
#Autowired
ObjectMapper objectMapper
#Transactional
#RequestMapping(path = "/{personId}", method = RequestMethod.PUT)
public ResponseEntity<?> update(
#PathVariable String personId,
#RequestBody PersonDTO dto
) {
Person p = people.findOne(personId);
objectMapper.updateValue(p, dto);
personRepository.save(p);
// return ...
}
}
Validating a DTO using java.util.Optional is a little different as well. It's documented here, but took me a while to find:
// ...
import javax.validation.constraints.NotNull;
import javax.validation.constraints.NotBlank;
import javax.validation.constraints.Pattern;
// ...
private class PersonDTO {
private Optional<#NotNull String> firstName;
private Optional<#NotBlank #Pattern(regexp = "...") String> lastName;
/* getters and setters ... */
}
In this case, firstName may not be set at all, but if set, may not be set to null if PersonDTO is validated.
//...
import javax.validation.Valid;
//...
public ResponseEntity<?> update(
#PathVariable String personId,
#RequestBody #Valid PersonDTO dto
) {
// ...
}
Also might be worth mentioning the use of Optional seems to be highly debated, and as of writing Lombok's maintainer(s) won't support it (see this question for example). This means using lombok.Data/lombok.Setter on a class with Optional fields with constraints doesn't work (it attempts to create setters with the constraints intact), so using #Setter/#Data causes an exception to be thrown as both the setter and the member variable have constraints set. It also seems better form to write the Setter without an Optional parameter, for example:
//...
import lombok.Getter;
//...
#Getter
private class PersonDTO {
private Optional<#NotNull String> firstName;
private Optional<#NotBlank #Pattern(regexp = "...") String> lastName;
public void setFirstName(String firstName) {
this.firstName = Optional.ofNullable(firstName);
}
// etc...
}
There is a better option, that does not involve changing your DTO's or to customize your setters.
It involves letting Jackson merge data with an existing data object, as follows:
MyData existingData = ...
ObjectReader readerForUpdating = objectMapper.readerForUpdating(existingData);
MyData mergedData = readerForUpdating.readValue(newData);
Any fields not present in newData will not overwrite data in existingData, but if a field is present it will be overwritten, even if it contains null.
Demo code:
ObjectMapper objectMapper = new ObjectMapper();
MyDTO dto = new MyDTO();
dto.setText("text");
dto.setAddress("address");
dto.setCity("city");
String json = "{\"text\": \"patched text\", \"city\": null}";
ObjectReader readerForUpdating = objectMapper.readerForUpdating(dto);
MyDTO merged = readerForUpdating.readValue(json);
Results in {"text": "patched text", "address": "address", "city": null}
Note that text and city were patched (city is now null) and that address was left alone.
In a Spring Rest Controller you will need to get the original JSON data instead of having Spring deserialize it in order to do this. So change your endpoint like this:
#Autowired ObjectMapper objectMapper;
#RequestMapping(path = "/{personId}", method = RequestMethod.PATCH)
public ResponseEntity<?> update(
#PathVariable String personId,
#RequestBody JsonNode jsonNode) {
RequestDTO existingData = getExistingDataFromSomewhere();
ObjectReader readerForUpdating = objectMapper.readerForUpdating(existingData);
RequestDTO mergedData = readerForUpdating.readValue(jsonNode);
...
}
Use boolean flags as jackson's author recommends.
class PersonDTO {
private String firstName;
private boolean isFirstNameDirty;
public void setFirstName(String firstName){
this.firstName = firstName;
this.isFirstNameDirty = true;
}
public String getFirstName() {
return firstName;
}
public boolean hasFirstName() {
return isFirstNameDirty;
}
}
Actually,if ignore the validation,you can solve your problem like this.
public class BusDto {
private Map<String, Object> changedAttrs = new HashMap<>();
/* getter and setter */
}
First, write a super class for your dto,like BusDto.
Second, change your dto to extend the super class, and change the
dto's set method,to put the attribute name and value to the
changedAttrs(beacause the spring would invoke the set when the
attribute has value no matter null or not null).
Third,traversal the map.
I have tried to solve the same problem. I found it quite easy to use JsonNode as the DTOs. This way you only get what is submitted.
You will need to write a MergeService yourself that does the actual work, similar to the BeanWrapper. I haven't found an existing framework that can do exactly what is needed. (If you use only Json requests you might be able to use Jacksons readForUpdate method.)
We actually use another node type as we need the same functionality from "standard form submits" and other service calls. Additionally the modifications should be applied within a transaction inside something called EntityService.
This MergeService will unfortunately become quite complex, as you will need to handle properties, lists, sets and maps yourself :)
The most problematic piece for me was to distinguish between changes within an element of a list/set and modifications or replacements of lists/sets.
And also validation will not be easy as you need to validate some properties against another model (the JPA entities in my case)
EDIT - Some mapping code (pseudo-code):
class SomeController {
#RequestMapping(value = { "/{id}" }, method = RequestMethod.POST, consumes = MediaType.APPLICATION_JSON_VALUE)
#ResponseBody
public void save(
#PathVariable("id") final Integer id,
#RequestBody final JsonNode modifications) {
modifierService.applyModifications(someEntityLoadedById, modifications);
}
}
class ModifierService {
public void applyModifications(Object updateObj, JsonNode node)
throws Exception {
BeanWrapperImpl bw = new BeanWrapperImpl(updateObj);
Iterator<String> fieldNames = node.fieldNames();
while (fieldNames.hasNext()) {
String fieldName = fieldNames.next();
Object valueToBeUpdated = node.get(fieldName);
Class<?> propertyType = bw.getPropertyType(fieldName);
if (propertyType == null) {
if (!ignoreUnkown) {
throw new IllegalArgumentException("Unkown field " + fieldName + " on type " + bw.getWrappedClass());
}
} else if (Map.class.isAssignableFrom(propertyType)) {
handleMap(bw, fieldName, valueToBeUpdated, ModificationType.MODIFY, createdObjects);
} else if (Collection.class.isAssignableFrom(propertyType)) {
handleCollection(bw, fieldName, valueToBeUpdated, ModificationType.MODIFY, createdObjects);
} else {
handleObject(bw, fieldName, valueToBeUpdated, propertyType, createdObjects);
}
}
}
}
Maybe too late for an answer, but you could:
By default, don't unset 'null' values. Provide an explicit list via query params what fields you want to unset. In such a way you can still send JSON that corresponds to your entity and have flexibility to unset fields when you need.
Depending on your use case, some endpoints may explicitly treat all null values as unset operations. A little bit dangerous for patching, but in some circumstances might be an option.
Another solution would be to imperatively deserialize the request body. By doing it, you will be able to collect user provided fields and selectively validate them.
So your DTO might look like this:
public class CatDto {
#NotBlank
private String name;
#Min(0)
#Max(100)
private int laziness;
#Max(3)
private int purringVolume;
}
And your controller can be something like this:
#RestController
#RequestMapping("/api/cats")
#io.swagger.v3.oas.annotations.parameters.RequestBody(
content = #Content(schema = #Schema(implementation = CatDto.class)))
// ^^ this passes your CatDto model to swagger (you must use springdoc to get it to work!)
public class CatController {
#Autowired
SmartValidator validator; // we'll use this to validate our request
#PatchMapping(path = "/{id}", consumes = "application/json")
public ResponseEntity<String> updateCat(
#PathVariable String id,
#RequestBody Map<String, Object> body
// ^^ no Valid annotation, no declarative DTO binding here!
) throws MethodArgumentNotValidException {
CatDto catDto = new CatDto();
WebDataBinder binder = new WebDataBinder(catDto);
BindingResult bindingResult = binder.getBindingResult();
List<String> patchFields = new ArrayList<>();
binder.bind(new MutablePropertyValues(body));
// ^^ imperatively bind to DTO
body.forEach((k, v) -> {
patchFields.add(k);
// ^^ collect user provided fields if you need
validator.validateValue(CatDto.class, k, v, bindingResult);
// ^^ imperatively validate user input
});
if (bindingResult.hasErrors()) {
throw new MethodArgumentNotValidException(null, bindingResult);
// ^^ this can be handled by your regular exception handler
}
// Here you can do normal stuff with your catDto.
// Map it to cat model, send to cat service, whatever.
return ResponseEntity.ok("cat updated");
}
}
No need for Optional's, no extra dependencies, your normal validation just works, your swagger looks good. The only problem is, you don't get proper merge patch on nested objects, but in many use cases that's not even required.
Probably to late but following code works for me to distinguish between null and not provided values
if(dto.getIban() == null){
log.info("Iban value is not provided");
}else if(dto.getIban().orElse(null) == null){
log.info("Iban is provided and has null value");
}else{
log.info("Iban value is : " + dto.getIban().get());
}
I have the following data model, and I want to get a specific object in the sub list objects, I know it's possible to get the entire list and go through each object and compare with what the search id, but I wonder if it is possible use MongoRepository to do this.
#Document
public class Host {
#Id
private String id;
#NotNull
private String name;
#DBRef
private List<Vouchers> listVoucher;
public Host() {
}
//Getters and Setters
}
And..
#Document
public class Vouchers {
#Id
private String id;
#NotNull
private int codeId;
public Vouchers() {
}
//Getters and Setters
}
The Repository Class:
public interface HostRepository extends MongoRepository<Host, String> {
List<Host> findAll();
Host findById(String id);
Host findByName(String name);
//How to build the correct query ??????????
List<Vouchers> findVouchersAll();
Vouchers findByVouchersById(String hostId, String voucherId);
}
The Controller Class:
#RestController
#RequestMapping(value = "api/v1/host")
public class VoucherController {
#Inject
HostRepository hostRepository;
#RequestMapping(value = "/{hostId}/voucher",method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
#ResponseBody
public List<Vouchers> list() {
return hostRepository.findVouchersAll();
}
#RequestMapping(value = "/{hostId}/voucher/{voucherId}", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
#ResponseBody
public Vouchers getOneVoucher(#PathVariable String hostId, #PathVariable String voucherId) {
Vouchers voucher = hostRepository.findByVouchersById(hostId, voucherId);
if (voucher != null) {
return voucher;
} else {
throw new VoucherNotFoundException(String.format("There is no voucher with id=%s", voucherId));
}
}
}
Thanks in Advance!
I think there is a way to do this although I have not tried this myself but maybe I can shed some light in how I would do it.
Firstly, I would rather use the more flexible way of querying mongodb by using MongoTemplate. MongoTemplate is already included in the Spring Boot Mongodb data library and it looks like you are already using the library so it is not an additional library that you will have to use. In Spring there is a way to #Autowired your MongoTemplate up so it is quick and easy to get the object for completing this task.
With mongoTemplate, you would do something like this:
Query query = new Query();
query.addCriteria(Criteria.where("listVouchers.id").is("1234"));
List<Host> host = mongoTemplate.find(query, Host.class);
Please see docs here: https://docs.mongodb.org/manual/tutorial/query-documents/