I am getting the following error - "The generated value is of the type integer instead of the type ‘string’" with 42crunch conformance scan with the following problem reported - "The API handles a faulty request without raising an error"
In the test scan, it is trying to pass the following request body -
{"type":1,"visitId":"xxxx","visitorId":"Ag5w\u0010l\u0014"}
So in above request, type is passed as integer but API is declared with type with "String" property.
#ApiModelProperty(dataType = "java.lang.String", value = "Type", example = "Data")
#Pattern(regexp = "^.*$")
#Size(min = 1, max = 50)
private String type;
I have the above annotation for the input request class. So eventhough type property is declared with ApiModelProperty annotation with dataType accepting only "java.lang.String", why is it throwing error?
I also have the #Valid annotation for the controller endpoint method which is accepting the request body.
public ResponseEnvelope recommendedProducts(
#Valid #RequestBody RecommendedProductRequest productRequest,
HttpServletResponse httpServletResponse) {
Please let know how to resolve this. Thanks!
Related
My Spring Boot Application in Kotlin has a POST endpoint defined like this:
fun postTermin( #PathVariable("pathID") pathID: String, #Validated #RequestBody termin: RequestBody): ResponseEntity<Appointment> {
return ResponseEntity(HttpStatus.NOT_IMPLEMENTED)
}
I'd like to take that "pathID" and use it to find an entity from a repository like so:
myRepository.findById(pathID)
The CRUDRepository I'm calling there is for an Entity "Dealer" where the ID is defined as:
#Id
#Column(name = "id", length = 10, nullable = false)
open var id: String = ""
The Problem: I get this compile error:
Kotlin: Type mismatch: inferred type is Optional<Dealer!> but Dealer?
was expected
What's the problem here? Why the "Optional"?
The comment by Slaw really helped.
As described in Spring Data JPA How to use Kotlin nulls instead of Optional there's also a "findByIdOrNull" function for CRUDRepository, i had missed that.
For my use case, that works.
I followed this tutorial to create a basic web app in Kotlin using Spring Boot. However, I fail to POST new entities with a many-to-one relationship to an existing resource.
My code:
#Entity
class Song(
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
var id: Long? = null,
var title: String,
#ManyToOne(fetch = FetchType.EAGER)
var addedBy: User)
#Entity
class User(
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
var id: Long? = null,
var email: String,
var displayName: String)
#RestController
#RequestMapping("/api/songs")
class SongController(private val repository: SongRepository) {
#PostMapping("/")
fun add(#RequestBody song: Song) =
repository.save(song)
This answer and others point out that you can reference another resource using its URI, but sending the following request:
{
"title": "Some title",
"addedBy": "http://localhost:8080/api/users/1"
}
gets me an errors with stack trace org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: Cannot construct instance of 'com.example.springboot.User' (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('http://localhost:8080/api/users/1'); nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot construct instance of 'com.example.springboot.User' (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('http://localhost:8080/api/users/1')\n at [Source: (PushbackInputStream); line: 6, column: 13] (through reference chain: com.example.springboot.Song[\"addedBy\"])
I got out of this that somewhere between Jackson/Hibernate/Spring Data it fails to convert the User resource URI into a User entity, but I'm in the dark where this magic should happen.
It seems to be an issue that occurs with Kotlin specifically. All the suggestions here on SO do not solve this specific error and the tutorial itself stops just short of dealing with relationships. If it's not the right approach at all to handle relationships this way I'd be eager to know what the preferred practice would be.
The tutorial is using HATEOAS. See the request body where they are referencing the corresponding child entity by using
"books" : { "href" : "http://localhost:8080/authors/1/books" }
Meaning you should also apply this pattern to your request. Otherwise this will not work. HATEOAS allows you to directly reference the related child entities by their corresponding resource path but you need to keep the necessary structure which your posted request body is missing. Further you must support HATEOAS in your WebService / WebApi / Spring Boot Project.
What you could do:
{
"title": "Some title",
"addedByUserId": "1"
}
Then
#PostMapping("/")
fun add(#RequestBody song: Song) =
val userEntity = userRepository.findById(song.getAddedByUserId())
Song newSong = new SongEntity();
// map props
newSong.setUser(userEntity)
repository.save(song)
That code does not work but I hope you get the idea.
Further
In your code you are treating the Request Body as an Entity. Please consider to separate your incoming Class and your Entity class. This would make several things easier.
I think you're missing jackson's kotlin module, it's exactly what it was created for.
https://github.com/FasterXML/jackson-module-kotlin
Just adding this dependency in your project will cause spring to autoconfigure your object mapper with this new module. If you have a Bean with your own created objectMapper then you need to configure it manually, there's a section about this in module's README.md
I am trying to use WebClient to Post a loan object to another microservice which saves this object in a DB. So theoretically the body (JSON loan object) should just be passed on to the API of the DB service. Somehow, I can't figure out how to accomplish this.
This is the API that accepts the JSON loan object:
Mapping: localhost:8081/loans
#PostMapping
public <T extends Loan> void addLoan(#Valid #NonNull #RequestBody T loan) {
loanService.createLoan(loan);
}
It then calls the loanService which should pass on the loan object to the DB-service API
public <T extends Loan> T createLoan(T loan) {
ParameterizedTypeReference<T> typeReference = new ParameterizedTypeReference<T>(){};
T a = client.post().uri("/loans").body(BodyInserters.fromValue(loan)).retrieve().bodyToMono(typeReference).block();
return a;
}
This is the API of that DB service:
Mapping: localhost:8080/api/v1/loans
#PostMapping
#ResponseBody
public <T extends Loan> T createLoan(#RequestBody T loan) {
return loanService.createLoan(loan);
}
And here is its service:
public <T extends Loan> T createLoan(T Loan) {
return (T) loanRepository.save(Loan);
}
If I just pass a loan object directly to the DB service API, everything works fine. But if I pass it to the other API, I get the following error:
"status": 500,
"error": "Internal Server Error",
"trace": "org.springframework.web.reactive.function.client.WebClientResponseException$InternalServerError: 500 Internal Server Error from POST http://localhost:8080/api/v1/loans/\n\tat org.springframework.web.reactive.function.client.WebClientResponseException.create(WebClientResponseException.java:201)\n\tSuppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException: \nError has been observed at the following site(s):\n\t|_ checkpoint ⇢ 500 from POST http://localhost:8080/api/v1/loans/ [DefaultWebClient]\nStack trace:\n\t\tat org.springframework.web.reactive.function.client.WebClientResponseException.create(WebClientResponseException.java:201)\n\t\tat org.springframework.web.reactive.function.client.DefaultClientResponse.lambda$createException$1(DefaultClientResponse.java:216)\n\t\tat reactor.core.publisher.FluxMap$MapSubscriber.onNext(FluxMap.java:106)\n\t\tat reactor.core.publisher.FluxOnErrorResume$ResumeSubscriber.onNext(FluxOnErrorResume.java:79)\n\t\tat reactor.core.publisher.FluxDefaultIfEmpty$DefaultIfEmptySubscriber.onNext(FluxDefaultIfEmpty.java:99)\n\t\tat reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onNext(FluxMapFuseable.java:127)\n\t\tat reactor.core.publisher.FluxContextWrite$ContextWriteSubscriber.onNext(FluxContextWrite.java:107)\n\t\tat reactor.core.publisher.FluxMapFuseable$MapFuseableConditionalSubscriber.onNext(FluxMapFuseable.java:295)\n\t\tat reactor.core.publisher.FluxFilterFuseable$FilterFuseableConditionalSubscriber.onNext(FluxFilterFuseable.java:337)\n\t\tat reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1784)\n\t\tat reactor.core.publisher.MonoCollect$CollectSubscriber.onComplete(MonoCollect.java:159)\n\t\tat reactor.core.publisher.FluxMap$MapSubscriber.onComplete(FluxMap.java:142)\n\t\tat reactor.core.publisher.FluxPeek$PeekSubscriber.onComplete(FluxPeek.java:259)\n\t\tat reactor.core.publisher.FluxMap$MapSubscriber.onComplete(FluxMap.java:142)\n\t\tat reactor.netty.channel.FluxReceive.onInboundComplete(FluxReceive.java:383)\n\t\tat reactor.netty.channel.ChannelOperations.onInboundComplete(ChannelOperations.java:396)\n\t\tat reactor.netty.channel.ChannelOperations.terminate(ChannelOperations.java:452)\n\t\tat reactor.netty.http.client.HttpClientOperations.onInboundNext(HttpClientOperations.java:664)\n\t\tat reactor.netty.channel.ChannelOperationsHandler.channelRead(ChannelOperationsHandler.java:94)\n\t\tat io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)\n\t\tat io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)\n\t\tat io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)\n\t\tat io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:103)\n\t\tat io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)\n\t\tat io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)\n\t\tat io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)\n\t\tat io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.fireChannelRead(CombinedChannelDuplexHandler.java:436)\n\t\tat io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:324)\n\t\tat io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:296)\n\t\tat io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:251)\n\t\tat io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)\n\t\tat io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)\n\t\tat io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)\n\t\tat io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)\n\t\tat io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)\n\t\tat io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)\n\t\tat io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)\n\t\tat io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:795)\n\t\tat io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:480)\n\t\tat io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:378)\n\t\tat io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)\n\t\tat io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)\n\t\tat io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)\n\t\tat java.base/java.lang.Thread.run(Thread.java:832)\n\tSuppressed: java.lang.Exception: #block terminated with an error\n\t\tat reactor.core.publisher.BlockingSingleSubscriber.blockingGet(BlockingSingleSubscriber.java:99)\n\t\tat reactor.core.publisher.Mono.block(Mono.java:1679)\n\t\tat de.rwth.swc.lab.ws2021.daifu.businesslogic.services.LoanService.createLoan(LoanService.java:39)\n\t\tat de.rwth.swc.lab.ws2021.daifu.businesslogic.api.LoanController.addLoan(LoanController.java:28)\n\t\tat java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)\n\t\tat java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:64)\n\t\tat java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)\n\t\tat java.base/java.lang.reflect.Method.invoke(Method.java:564)\n\t\tat org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:197)\n\t\tat org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:141)\n\t\tat org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:106)\n\t\tat org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:893)\n\t\tat org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:807)\n\t\tat org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)\n\t\tat org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1061)\n\t\tat org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:961)\n\t\tat org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)\n\t\tat org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909)\n\t\tat javax.servlet.http.HttpServlet.service(HttpServlet.java:652)\n\t\tat org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)\n\t\tat javax.servlet.http.HttpServlet.service(HttpServlet.java:733)\n\t\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)\n\t\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\n\t\tat org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)\n\t\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)\n\t\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\n\t\tat org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100)\n\t\tat org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)\n\t\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)\n\t\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\n\t\tat org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93)\n\t\tat org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)\n\t\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)\n\t\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\n\t\tat org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)\n\t\tat org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)\n\t\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)\n\t\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\n\t\tat org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)\n\t\tat org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97)\n\t\tat org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542)\n\t\tat org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:143)\n\t\tat org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)\n\t\tat org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78)\n\t\tat org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)\n\t\tat org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374)\n\t\tat org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)\n\t\tat org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)\n\t\tat org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1590)\n\t\tat org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)\n\t\tat java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)\n\t\tat java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)\n\t\tat org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)\n\t\tat java.base/java.lang.Thread.run(Thread.java:832)\n",
"message": "500 Internal Server Error from POST http://localhost:8080/api/v1/loans/",
"path": "/loans/"
This is the server-side error:
Servlet.service() for servlet [dispatcherServlet] in context with path [/api/v1] threw exception [Request processing failed; nested exception is org.springframework.dao.DataIntegrityViolationException: not-null property references a null or transient value : de.rwth.swc.lab.ws2021.daifu.dataservice.data.models.loans.PrivateLoan.customer; nested exception is org.hibernate.PropertyValueException: not-null property references a null or transient value : de.rwth.swc.lab.ws2021.daifu.dataservice.data.models.loans.PrivateLoan.customer] with root cause org.hibernate.PropertyValueException: not-null property references a null or transient value : de.rwth.swc.lab.ws2021.daifu.dataservice.data.models.loans.PrivateLoan.customer
And finally, this is the POST-body:
{
"amount": 10000.00,
"balance": -2000.00,
"customer": {"id": 1},
"interest": 0.06,
"status": "TIMELY",
"reason": "Some reaseon",
"type": "privateLoan"
}
The error says the "not-null property references a null or transient value" but the exact same request works for a direct POST-request to the 2nd API which doesn't make sense to me.
Here is the loan class:
#Entity
#Inheritance(strategy = InheritanceType.TABLE_PER_CLASS)
#Getter
#Setter
#NoArgsConstructor
#JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.PROPERTY, property = "type")
#JsonSubTypes({
#JsonSubTypes.Type(value = CarLoan.class, name = "carLoan"),
#JsonSubTypes.Type(value = ConstructionLoan.class, name = "constructionLoan"),
#JsonSubTypes.Type(value = Mortgage.class, name = "mortgage"),
#JsonSubTypes.Type(value = PrivateLoan.class, name = "privateLoan"),
#JsonSubTypes.Type(value = PropertyLoan.class, name = "propertyLoan")
})
#ApiModel(
discriminator = "type",
subTypes = {CarLoan.class, ConstructionLoan.class, Mortgage.class, PrivateLoan.class, PropertyLoan.class}
)
public abstract class Loan {
#Id
#GeneratedValue(strategy = GenerationType.TABLE)
#Column(name = "id")
#ApiModelProperty(required = false, hidden = true)
protected Integer id;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "customer_id", nullable = false)
#JsonBackReference(value = "customer-loans")
protected Customer customer;
#OneToMany(mappedBy = "loan", cascade = CascadeType.ALL)
#JsonManagedReference(value = "loan-loanRates")
private Set<LoanRate> loanRates;
#NonNull
protected Double amount;
#NonNull
protected Double interest;
#NonNull
protected Double balance;
#NonNull
protected LoanStatus status;
public enum LoanStatus {
TIMELY("timely"),
GRACE_PERIOD("grace period"),
DEFAULT("default"),
DEFICIT("deficit"),
IRRECOVERABLE_DEBT("irrecoverable debt"),
CLOSED("closed");
#Getter
private String stringRepresentation;
private LoanStatus(String s) {
this.stringRepresentation = s;
}
}
public <T extends Loan> boolean isOfSameInstance(T otherLoan) {
return (this.getClass().equals(otherLoan.getClass()));
}
}
Let me know if I should post anything else.
Thanks in advance.
The problem is due to the models being used in the projects. As your are reusing the model classes of the one webservice which offers the CRUD api for the backend, you are also reusing the jackson's #JsonManagedReference and #JsonBackReference. This leads to null values for the models being defined as the back reference, such as the customer in you loan class. Jackson does not serialize such tagged objects to JSON in order to not run into a stackoverflow due to infinite recursion. Thus, when you serialize a loan model in your service and send the request to the other service, jackson nulls the back reference, e.g. customer in the loan model and the 2nd webservice therefore receives an invalid loan model, since a loan model is required to have a customer not to be null.
I suggest to either remove the jackson annotations from the models in the service you develop, which would required copy pasted model classes (on the one side the classes using the required jackson annotations in the web service, and on the other side the classes not using these in the other web service). However, this solution has the typical disadvantages of duplicated code. The more elegant but more complicated solution will be to implement a custom jackson serializer and deserializer by specializing jackson's StdSerializer<Loan> and StdDeserializer<Loan>. These custom serializers and deserializers should override its serialize(T value, JsonGenerator gen, SerializerProvider provider) respectively its deserialize(JsonParser, DeserializationContext) method such that the #JsonManagedReference and #JsonBackReference, as well as, if being used, #JsonIgnore annotations in the model are being ignored.
It might be sufficient to just implement a custom serializer. However, I guess that you will also run into problems when receiving a response from the other web service when not using a custom deserializer.
This error may happen if the customer object in the loan you are trying to save is null or not yet added to the database (even though it is set in loan). You should check before saving the Loan in the DB if customer is null or not. If not, and if it is a customer not yet in the database, you should consider adding it first or specify CascadeType.PERSIST in the relation type annotation. In any case, it would be better if you post the entire model that both services are using.
This is our Controller
#GetMapping(path = "/getUsersForHierarchy/{entity}/{hierId}", produces = MediaType.APPLICATION_JSON_VALUE)
public ResponseEntity<List<UserInfo>> getUsersForHierarchy(#PathVariable(name = "entity", required = true) int entity,
#PathVariable(name = "hierId", required = true) Integer hierId) {
..................
..................
}
We are expecting two Path variables, one is of int type (entity) and the other is Integer type (hierId). hierId can be null or any numeric value and thats why its kept as Wrapper. But its gives error while firing the request like this
http://localhost:5010/v1/accountholder/userinfo/getUsersForHierarchy/5/null
Now a Wrapper is meant to accept null values, but we are getting error like this
Failed to convert value of type 'java.lang.String' to required type 'java.lang.Integer'; nested exception is java.lang.NumberFormatException: For input string: "null"
If we change Integer to String the call is getting inside the controller, but for further proceedings we need to use Integer.
We looked into this Spring MVC #Path variable with null value, and tried invoking the API with change in URL like this
http://localhost:5010/v1/accountholder/userinfo/getUsersForHierarchy/5/blaaa/null, but the error is still the same.
What should be done?
If you want it to be nullable you can achieve it with the following. First of all, if it's nullable the required property should be false. Also, considering required = true is the default, there's no need to specify it and if the name of the path variable matches the name of the corresponding variable you don't have to specify the name either.
#GetMapping(value = {
"/getUsersForHierarchy/{entity}/",
"/getUsersForHierarchy/{entity}/{hierId}"
},
produces = MediaType.APPLICATION_JSON_VALUE)
public ResponseEntity<List<UserInfo>> getUsersForHierarchy(
#PathVariable int entity,
#PathVariable(required = false) Integer hierId) {
}
Considering I don't like to deliberately allow a null value into the application, another nice to have could be having the hierId required with type Optional, so the following will give you a Optional.empty when just /getUsersForHierarchy/123/ is invoked and hierId is null. Otherwise it will populate the optional when hierId is provided invoking /getUsersForHierarchy/123/321:
#GetMapping(value = {
"/getUsersForHierarchy/{entity}/",
"/getUsersForHierarchy/{entity}/{hierId}"
},
produces = MediaType.APPLICATION_JSON_VALUE)
public ResponseEntity<List<UserInfo>> getUsersForHierarchy(
#PathVariable int entity,
#PathVariable Optional<Integer> hierId) {
}
I would like to gather all of my query parameters into a pojo and perform additional validation of the fields.
I have read that I can simply create an object and spring-boot will automatically set those request parameters on it.
#GetMaping
public ResponseEntity<?> listEntities(#RequestParam(value = "page-number", defaultValue = "0") #Min(0) Integer pageNumber,
#RequestParam(value = "page-size", defaultValue = "100") #Min(1) Integer pageSize ... )
I am thinking to create a class called RequestParamsDTO, where I'd have my query params responsible for the pagination.
But in order to have those fields set on the RequestParamsDTO, I'd have to match the name of the request param with the field name. But it won't be a valid variable name: page-size.
There must be some workaround, similar to #RequestParam's value attribute, that would set given request param on my field in the DTO.
Please advise.
Someone already purposed this feature before such that you can do the following .But unfortunately it is declined due to inactivity response :
public class RequestParamsDTO{
#RequestParam(value="page-number",defaultValue="0")
#Min(0)
private Integer pageNumber;
#RequestParam(value = "page-size", defaultValue = "100")
#Min(1)
Integer pageSize
}
The most similar things that you can do is using its #ModelAttribute which will resolve the parameter in the following orders:
From the model if already added by using Model.
From the HTTP session by using #SessionAttributes.
From a URI path variable passed through a Converter (see the next example).
From the invocation of a default constructor.
From the invocation of a “primary constructor” with arguments that match to Servlet request parameters. Argument names are determined through JavaBeans #ConstructorProperties or through runtime-retained parameter names in the bytecode.
That means the RequestParamsDTO cannot not have any default constructor (constructor that is without arguments) .It should have a "primary constructor" which you can use #ConstructorProperties to define which request parameters are mapped to the constructor arguments :
public class RequestParamsDTO{
#Min(0)
Integer pageNumber;
#Min(1)
Integer pageSize;
#ConstructorProperties({"page-number","page-size"})
public RequestParamsDTO(Integer pageNumber, Integer pageSize) {
this.pageNumber = pageNumber != null ? pageNumber : 0;
this.pageSize = pageSize != null ? pageSize : 100;
}
}
And the controller method becomes:
#GetMaping
public ResponseEntity<?> listEntities(#Valid RequestParamsDTO request){
}
Notes:
There is no equivalent annotation for #RequestParam 's defaultValue,so need to implement in the constructor manually.
If the controller method argument does not match the values in this , it will resolved as #ModelAttribute even though #ModelAttribute is not annotated on it explicitly.
To be honest this seems like a lot of effort for a functionality that exists already in spring-boot. You can either extend your repositories from PagingAndSortingRepository and have pagination added whenever you call a collection resource.
Or you can write a custom query method (or overwrite an existing one) and add this:
Page<Person> findByFirstname(String firstname, Pageable pageable);
This way spring boot will automatically add all those parameters you want to the Request.