I have some problems combining JAX-RS (in JBoss Wildfly container) with JSON payload and with JPA assiciations. Follwoing scenario:
There are two JPA entities
#Entity
class Organization {
#Id
private long id;
private String name;
}
#Entity
class Empolyee {
#Id
private long id;
#Id
private String name;
#ManyToOne(fetch = FetchType.EAGER)
#JsonProperty("organization_id")
#JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class, property = "id")
#JsonIdentityReference(alwaysAsId = true)
private Organization organization;
}
Next I have a JAX-RS service to create a new Employee with the following signature:
#POST
#Consumes({ "application/json" })
public Response create(final Employee employee) {
}
The JSON for a new Employee sent by the client looks like:
{
"name" : "Sam Sample",
"organization_id" : 2
}
My problem is that this JSON (obviously) cannot be deserialized into an instance of "Employee" since the mapping of the "organization_id" to the corresponding JPA Entity fails.
How can I configure JAX-RS (or the Jackson JSON mapper) to interpret the "orgainization_id" as the id of a JPA entity?
With Jackson you could define a custom deserializer (see this and this) that fetches the Organization entity based on the value of organization_id.
Edit:
Check this example for how to configure JAX-RS using Jackson with a custom deserializer programmatically (as opposed to via annotations):
#Provider
#Produces(MediaType.APPLICATION_JSON)
public class JacksonContextResolver implements ContextResolver<ObjectMapper> {
private ObjectMapper objectMapper;
public JacksonContextResolver() throws Exception {
this.objectMapper = new ObjectMapper().configure(DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES, false);
SimpleModule myModule = new SimpleModule("MyModule", new Version(1, 0, 0, null));
myModule.addDeserializer(MyType.class, new MyTypeDeserializer());
objectMapper.registerModule(myModule);
}
public ObjectMapper getContext(Class<?> objectType) {
return objectMapper;
}
}
Related
I'm doing a dummy app of a hostpital. The problem I'm having is that, I'm trying to verify that when a Patient is created, the fields passed are of the correct type, but whenever I POST an Int in a String field, it doesn't fail and just transform the Int to String. The field I'm trying to make fail is "surname", which by the definition of the Patient class, is a String.
If I do this (I pass a number to the "surname" field):
{
"name": "John",
"surname": 43,
"sickness": "headache"
}
It just transforms 43 into a String by the time its in the Controller method.
Here we have the Patient object:
#Data
#Entity
#NoArgsConstructor
#AllArgsConstructor
public class Patient implements Serializable {
private static final long serialVersionUID = 4518011202924886996L;
#Id
//TODO: posible cambiar luego la generationType
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "patient_id")
private Long id;
#Column(name = "patient_name")
#JsonProperty(required = true)
private String name;
#Column(name = "patient_surname")
#JsonProperty(required = true)
private String surname;
#Column(name = "patient_sickness")
#JsonProperty(required = true)
private String sickness;
}
And this is the controller class:
#Controller
#Path("/patient")
#Produces(MediaType.APPLICATION_JSON + ";charset=utf-8")
public class PatientController {
#POST
#Path("")
public ResponseEntity<Object> postPatient(final Patient patient) {
ResponseEntity<Object> createdPatient = patientBusiness.createPatient(patient);
return new ResponseEntity<Patient>(createdPatient.getBody(), createdPatient.getStatusCode());
}
EDIT 1:
Following the "clues" and closing the circle of attention, I tried modifying the ObjectMapper, but my configuration isn't applying. I'm still getting the error from above.
This is the config class:
#Configuration
public class JacksonConfig {
#Bean
#Primary
public ObjectMapper getModifiedObjectMapper() {
ObjectMapper mapper = new ObjectMapper();
mapper.configure(MapperFeature.ALLOW_COERCION_OF_SCALARS, false);
mapper.coercionConfigFor(LogicalType.Integer).setCoercion(CoercionInputShape.String, CoercionAction.Fail);
return mapper;
}
}
Even added the property to the application.yml, but still nothing:
spring:
jackson:
mapper:
allow-coercion-of-scalars: false
Any help is appreciated. Thx.
In the end I referred to this post to do a deserializer and a module to just have it along all the program, not just the field I want not to be transformed.
Disable conversion of scalars to strings when deserializing with Jackson
I have a class implementing Serializable, which is mapped to a database table. It looks like this:
#Entity
#Table(name = "users")
public class Users implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
public Long id;
#Column(name = "name", nullable = false)
public String name;
#Column(name = "email", nullable = false)
public String email;
#Column(name = "status", nullable = false)
public String status;
}
For the most part, I want all these properties to be included in the JSON. However, there is a specific case where I want to exclude status, but I can't figure out a good way of doing this with Jackson.
My controller looks something like this:
public class UserController {
private final ObjectMapper mapper;
#Inject
public UserController(ObjectMapper mapper) {
this.mapper = mapper;
}
public CompletionStage<JsonNode> getUserList() {
// Get list of Users and return the JSON; with all User properties included
}
public CompletionStage<JsonNode> getUser(Long userId) {
// Get a single user from JPA, in a promise
return userDatabase.get(userId).thenApply(user -> { // user is type User
// Here, I don't want to include "status" in the JSON.
return mapper.valueToTree(user);
});
}
}
So when I do mapper.valueToTree(user), of course, it includes all properties of User, but I want to exclude status in this specific route/function while keeping it included in all other places its serialized.
I know I can use #JsonIgnore to ignore it always, but can I do this just sometimes?
Some solutions I thought of are:
filter through the properties and get rid of status
Copy user over to an ObjectNode and manually remove status
Neither of these seems ideal though, I feel like there has to be a cleaner approach with Jackson.
I have two entities (Project, OtherData) with one abstract entity. I'm using MySQL and Quarkus framework.
Problem: When I try to save Project entity field project_id remains null.
Table schemas:
On next picture there is shown, fk constraint in "project_other_data" table:
Abstract Entity:
#MappedSuperclass
public class AbstractEntity {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
protected Long id;
// getters and setters
}
Project Entity
#Entity
#Table(name = "projects")
public class Project extends AbstractEntity {
#NotNull
#Column(name = "name")
private String name;
#NotNull
#Column(name = "surname")
private String surname;
#Column(name = "date_create")
#JsonbDateFormat(value = "yyyy-MM-dd")
private LocalDate dateCreate;
#Column(name = "date_update")
#JsonbDateFormat(value = "yyyy-MM-dd")
private LocalDate dateUpdate;
#OneToOne(mappedBy = "project", cascade = CascadeType.ALL)
private OtherData otherData;
// getters and setters
}
OtherData Entity
#Entity
#Table(name = "project_other_data")
public class OtherData extends AbstractEntity {
#OneToOne
#JoinColumn(name = "project_id")
private Project project;
#Column(name = "days_in_year")
private Integer daysInYear;
#Column(name = "holidays_in_year")
private Integer holidaysInYear;
#Column(name = "weeks_in_year")
private Integer weeksInYear;
#Column(name = "free_saturdays")
private Integer freeSaturdays;
#Column(name = "downtime_coefficient")
private BigDecimal downtimeCoefficient;
#Column(name = "changes")
private Integer changes;
// getters and setters
}
Saving entities with code:
#Path("projects")
#Produces(MediaType.APPLICATION_JSON)
#Consumes(MediaType.APPLICATION_JSON)
public class ProjectRest {
#Inject
ProjectService projectService;
#POST
public Response saveProject(Project project) {
return Response.ok(projectService.saveProject(project)).build();
}
}
#RequestScoped
#Transactional
public class ProjectService {
#Inject
EntityManager entityManager;
public Project saveProject(Project project) {
if (project.getId() == null) {
entityManager.persist(project);
} else {
entityManager.merge(project);
}
return project;
}
}
I was able to reproduce the problem by POSTing a new Project with an embedded OtherData. The body I used for the POST:
{
"name": "John",
"surname": "Doe",
"otherData": {}
}
Point is: the database entity is also used as DTO. Thus, the field project in otherData for the request body is set to null (since no Project is passed along this would be a recursive infinite definition).
During processing the entity from the rest controller to the service to the repository, the project of otherData is never set. A quick fix is to modify ProjectService::saveProject as follows:
public Project saveProject(Project project) {
project.getOtherData().setProject(project); // This line was added
if (project.getId() == null) {
entityManager.persist(project);
} else {
entityManager.merge(project);
}
return project;
}
This will fix the database issue (the project_id will be set), but leads to the next issue. The response body cannot be serialized due to an
org.jboss.resteasy.spi.UnhandledException: javax.ws.rs.ProcessingException: RESTEASY008205: JSON Binding serialization error javax.json.bind.JsonbException: Unable to serialize property 'otherData' from com.nikitap.org_prod.entities.Project
...
Caused by: javax.json.bind.JsonbException: Recursive reference has been found in class class com.nikitap.org_prod.entities.Project.
The object structure is cyclic (project references otherData, which return references project, ...) and Jackson is unable to resolve this cycle.
To fix this issue, I would suggest to separate DTOs and database entity and explicitly map between them. In essence:
Structure the Dto-object to represent the JSON-Request and -Response you expect to receive, in a non-cyclic order
Transfer JSON-related annotations from the database entity classes to the DTO classes
In the service- or repository-layer (your choice), map the DTO to the database entites, setting all fields (including the references from project to otherData and vice-versa)
In the same layer, map database-entites back to non-cyclic DTOs
Return the DTOs from the REST endpoint
I am working on an e-policy project where i need to save different types of policies. For simplicity i am considering only two types "LifeInsurance" and "AutoInsurance". What i want to achieve is if the JSON request to create policy contains "type":"AUTO_INSURANCE" then the request should be mapped to AutoInsurance.class likewise for LifeInsurance but currently in spring boot app the request is getting mapped to parent class Policy eliminating the specific request fields for auto/Life insurance. The domain model i have created is as below.
#Entity
#Inheritance(strategy = InheritanceType.JOINED)
#NoArgsConstructor
#Getter
#Setter
#JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include =
JsonTypeInfo.As.PROPERTY, property = "type")
#JsonSubTypes({ #Type(value = AutoInsurance.class, name = "AUTO_INSURANCE"),
#Type(value = LifeInsurance.class) })
public class Policy {
#Id
#GeneratedValue
private Long id;
private String policyNumber;
#Enumerated(EnumType.STRING)
private PolicyType policyType;
private String name;
}
My AutoInsurance class is below.
#Entity
#NoArgsConstructor
#Getter
#Setter
#JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.PROPERTY, property = "type")
#JsonTypeName(value = "AUTO_INSURANCE")
public class AutoInsurance extends Policy {
#Id
#GeneratedValue
private Long id;
private String vehicleNumber;
private String model;
private String vehicleType;
private String vehicleName;
}
Below is LifeInsurance type child class
#Entity
#NoArgsConstructor
#Getter
#Setter
#JsonTypeName(value = "LIFE_INSURANCE")
public class LifeInsurance extends Policy {
#OneToMany(mappedBy = "policy")
private List<Dependents> dependents;
private String medicalIssues;
private String medication;
private String treatments;
}
To save the policy details, I am sending JSON request from UI with a "type" property indicating the type of insurance in the request.
When i run the below test method, JSON request gets mapped to the correct child class as required.
public static void main(String[] args) throws JsonParseException, JsonMappingException, IOException {
ObjectMapper map = new ObjectMapper();
String s = "{\"id\": 1,\"policyNumber\": \"Aut-123\",\"type\": \"AUTO_INSURANCE\",\"policyType\": \"AUTO_INSURANCE\",\"name\": null,\"address\": null,\"contact\": null,\"agentNumber\": null,\"agentName\": null,\"issuedOn\": null,\"startDate\": null,\"endDate\": null,\"vehicleNumber\": \"HR\",\"model\": null,\"vehicleType\": \"SUV\",\"vehicleName\": null}";
Policy p = map.readValue(s, Policy.class);
System.out.println(p.getClass());
//SpringApplication.run(EPolicyApplication.class, args);
}
But when i run the same in Spring boot in a RESTController postmapping, I am getting a PArent class object instead of the child class object.
#RestController
#RequestMapping("/policy")
public class PolicyController {
#PostMapping
public void savePolicy(Policy policy) {
System.out.println(policy.getClass());
}
}
I can get the JSON as string, autowire objectmapper and parse manually but i want to understand if its a known issue and if anyone else has faced the same with Spring boot. I have searched for solutions on this but i got was solution to deserializing to polymorphic classes but nothing related to issue with Spring boot.
In your method you haven't annotated the Policy method argument with #RequestBody. Which leads to Spring creating just an instance of Policy instead of using Jackson to convert the request body.
#PostMapping
public void savePolicy(#RequestBody Policy policy) {
System.out.println(policy.getClass());
}
Adding the #RequestBody will make that Spring uses Jackson to deserialize the request body and with that your annotations/configuration will be effective.
I have placed the annotation over the class/pojo and also configured the mapper, but it still serialize null values
I am using Hibernate 4.3.7Final and Jackson 2.4.4. The collections are lazy loaded
Pojo : Removed getter and setters
#JsonInclude(Include.NON_NULL)
#Entity
#Table
public class School {
#Id
#GeneratedValue
private int id;
#OneToMany(cascade=CascadeType.ALL,fetch= FetchType.LAZY)
private List<Student> students;
#OneToMany(cascade=CascadeType.ALL,fetch= FetchType.LAZY)
private List<Employee> staff;
}
JSONMapper:
#Component
public class JSONMapper extends ObjectMapper {
/**
*
*/
private static final long serialVersionUID = -3131980955975958812L;
//ref http://blog.pastelstudios.com/2012/03/12/spring-3-1-hibernate-4-jackson-module-hibernate/
public JSONMapper() {
Hibernate4Module hm = new Hibernate4Module();
registerModule(hm);
configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false);
configure(SerializationFeature.INDENT_OUTPUT , false);
configure(MapperFeature.DEFAULT_VIEW_INCLUSION, false);
setSerializationInclusion(Include.NON_NULL);
}
}
Output :
{"id":1,"students":null,"staff":null}
Try using JsonInclude.NON_EMPTY instead.
You may want to file a bug against project; it could be that handling for lazy-loaded collections (which do require special handling and overrides to default one) is not doing proper inclusion checks.