I'm new to reactive programming and micronaut. I'm basically working on simple CRUD APIs. I'm using Kotlin with micronaut. I'm not sure why the DB is not returning any Data and I'm stuck with this.
#JdbcRepository(dialect = Dialect.POSTGRES)
interface EmployeeCrudRepository: ReactiveStreamsCrudRepository<EmployeeMaster, Int>, EmployeeRepository {
}
interface EmployeeRepository {
fun findByEmployeeIdAndTcin(employeeId: UUID, tcin: String): Mono<EmployeeMaster>
}
#MappedEntity
#Table(name="employee")
data class EmployeeMaster (
#Id
#Column(name = "transaction_id")
val transactionId: Int,
#Column(name = "employee_id")
val employeeId: UUID,
#Column(name = "item_id")
val itemId: UUID
)
fun getEmployeeDetailsResponse(registryId: UUID, itemId: String) : Mono<EmployeeDetailsDTO> {
return getEmployeeDetails(employeeId, itemId)
.map {
employeeDetails -> EmployeeDetailsDTO(employeeDetails)
}
.switchIfEmpty {
logger.info("No records found")
Mono.just(ItemDetailsDTO())
}
}
fun getEmployeeDetails(employeeId: UUID, itemId: String) : Mono<EmployeeDetailsDTO> {
return employeeRepository.findByEmployeeIdAndTcin(registryId = registryId, tcin = itemId)
.map {
employeeDetails -> EmployeeDetailsDTO(employeeDetails)
}
.switchIfEmpty {
logger.info("No records found")
Mono.just(EmployeeDetailsDTO())
}
}
I'm confused as to how to debug this to find the issue. The credentials all seem to be fine and the record I'm searching for exists in the DB.
flyway {
// ./gradlew -Ppostgres_host=localhost -Ppostgres_ssl='' -Ppostgres_user=postgres -Ppostgres_pwd=postgres flywayMigrate -i
url = "jdbc:postgresql://${postgres_host}:5432/postgres${postgres_ssl}"
user = "${postgres_user}"
password = "${postgres_pwd}"
schemas = ['public']
}
Issue Found:
My Bad, I was sending some other value and didn't realise that the value was incorrect. The implementation was fine and returning the response as expected. I'm writing kotlin and micronaut code for the first time and at the back of my head it always feels like the implementation was wrong.
Take a look at Access a Database with Micronaut Data R2DBC.
There are a number of things in your example that look wrong:
#JdbcRepository(dialect = Dialect.POSTGRES) should be #R2dbcRepository.
#Table and #Column are JPA.
#MappedEntity("employee")
#MappedProperty("item_id")
You might not need #MappedProperty("item_id"), itemId should be mapped to item_id.
Related
I have a problem returning data class and handling it in the frontend. I dont know if the problem relies in the backend or the frontend
#RestController
#CrossOrigin
#RequestMapping(path = ["/1/private/profile"])
class ProfileController {
...OTHER CODE...
#GetMapping(
path = ["/getUser"],
consumes = [MediaType.APPLICATION_JSON_VALUE],
produces = [MediaType.APPLICATION_JSON_VALUE])
fun getUser(#RequestHeader(AUTHORIZATION) token: String): User? {
val uid = token.getUid()
val user = userRepository?.findItemByUid(uid)
user?.let {
return user
}?: kotlin.run {
return null
}
}
}
This is the controller holding the endpoint called from the frontend. The endpoint is returning 200 when called from the frontend. But the body returned is completely wrong.
response body: {"id":{"timestamp":1672696689,"date…y":"Sweden","uid":"4yRhpe43hHUwDGkqMqVBqX3G60p2"}
But expected is json string from the data class below
#Document("users")
data class User(
val id: ObjectId = ObjectId.get(),
val fullName: String,
val email: String,
val country: String,
val uid: String
)
What could i be doing wrong? It works perfectly if the endpoint for some reason returns a list of objects.
I am using Vapor and Fluent. I want to define a user model like below, but I get an error saying:
Fatal error: Error raised at top level: previousError(server: multiple primary keys for table "users" are not allowed
Is it not possible to define multiple UUIDs in one model?
import Vapor
import FluentPostgresDriver
final class User: Model, Content {
static let schema = "users"
#ID(custom: "id")
var id: Int?
#Field(key: "email")
var email: String
#Field(key: "password")
var password: String
#ID(custom: "public_id")
var public_id: UUID?
init() { }
init(id: Int? = nil,email: String, password:String, public_id: UUID? = nil) {
self.id = id
self.email = email
self.password = password
self.public_id = public_id
}
}
struct CreateUser: Migration {
func prepare(on database: Database) -> EventLoopFuture<Void> {
database.schema("users")
.field("id", .int, .identifier(auto: true))
.field("email", .string)
.field("password", .string)
.field("public_id", .uuid,?????)
.create()
}
.....
}
Instead of marking the public UUID as #ID, just mark it as another #Field (string type is easiest, but you can also do binary [16 bytes] if you're feeling like wearing a propeller beanie), and make it required.
During the create, you'll have to actually invoke a UUID generation function, but that ought to be easy enough.
But, why not make the primary key the UUID, instead of having two identifiers? It takes a little more room in the database, but might be worth avoiding the headache of having several different ids.
I am currently struggling with doing an upsert with vapor/fluent. I have a model something like this:
struct DeviceToken: PostgreSQLModel {
var id: Int?
var token: String
var updatedAt: Date = Date()
init(id: Int? = nil, token: String, updatedAt: Date = Date()) {
self.id = id
self.token = token
self.updatedAt = updatedAt
}
}
struct Account: PostgreSQLModel {
var id: Int?
let username: String
let service: String
...
let deviceTokenId: DeviceToken.ID
init(id: Int? = nil, service: String, username: String, ..., deviceTokenId: DeviceToken.ID) {
self.id = id
self.username = username
....
self.deviceTokenId = deviceTokenId
}
}
From the client something like
{
"deviceToken": {
"token": "ab123",
"updatedAt": "01-01-2019 10:10:10"
},
"account": {
"username": "user1",
"service": "some service"
}
}
is send.
What I'd like to do is to insert the new models if they do not exist else update them. I saw the create(orUpdate:) method however this will only update if the id is the same (in my understanding). Since the client does not send the id i am not quite sure how to handle this.
Also I can't decode the model since the account is send without the deviceTokenId and therefore the decoding will fail. I guess I can address the latter problem by overriding NodeCovertible or by using two different models (one for decoding the json without the id and the actual model from above). However the first problem still remains.
What I exactly want to do is:
Update a DeviceToken if an entry with token already exists else create it
If an account with the combination of username and service already exists update its username, service and deviceTokenId else create it. DeviceTokenId is the id returned from 1.
Any chance you can help me out here ?
For everyone who is interested:
I solved it by writing an extension on PostgreSQLModel to supply an upsert method. I added a gist for you to have a look at: here.
Since these kind of links sometimes are broken when you need the information here a quick overview:
Actual upsert implementation:
extension QueryBuilder
where Result: PostgreSQLModel, Result.Database == Database {
/// Creates the model or updates it depending on whether a model
/// with the same ID already exists.
internal func upsert(_ model: Result,
columns: [PostgreSQLColumnIdentifier]) -> Future<Result> {
let row = SQLQueryEncoder(PostgreSQLExpression.self).encode(model)
/// remove id from row if not available
/// otherwise the not-null constraint will break
row = row.filter { (key, value) -> Bool in
if key == "id" && value.isNull { return false }
return true
}
let values = row
.map { row -> (PostgreSQLIdentifier, PostgreSQLExpression) in
return (.identifier(row.key), row.value)
}
self.query.upsert = .upsert(columns, values)
return create(model)
}
}
Convenience methods
extension PostgreSQLModel {
/// Creates the model or updates it depending on whether a model
/// with the same ID already exists.
internal func upsert(on connection: DatabaseConnectable) -> Future<Self> {
return Self
.query(on: connection)
.upsert(self, columns: [.keyPath(Self.idKey)])
}
internal func upsert<U>(on connection: DatabaseConnectable,
onConflict keyPath: KeyPath<Self, U>) -> Future<Self> {
return Self
.query(on: connection)
.upsert(self, columns: [.keyPath(keyPath)])
}
....
}
I solved the other problem I had that my database model could not be decoded since the id was not send from the client, by using a inner struct which would hold only the properties the client would send. The id and other database generated properties are in the outer struct. Something like:
struct DatabaseModel: PostgreSQLModel {
var id: Int?
var someProperty: String
init(id: Int? = nil, form: DatabaseModelForm) {
self.id = id
self.someProperty = form.someProperty
}
struct DatabaseModelForm: Content {
let someProperty: String
}
}
I'm building an API with Spring Boot and Kotlin. I am trying to generate a structure the following way in MongoDB.
I understand that in MongoDb the concept of relationships between entities does not exist, so I will use the strategy of embedded documents. That is, to embed the Reunión in the Proyecto, and the Participante in the Reunión.
I have a main class called Proyecto and NewProyecto, that contains as property a list of reuniones of type NewReunion. I use two different classes to create and return data.
Proyecto.kt
#Document(collection = "proyectos")
#TypeAlias("proyecto")
data class Proyecto (
#Id
val id: String,
val nombre: String,
val area: String,
val fecha:String,
val reuniones: List<Reunion>?
){}
#Document(collection = "proyectos")
#TypeAlias("newproyecto")
data class NewProyecto (
#Id
val id: String?,//Es posiblemente nulo porqué se crea automáticamente
var nombre: String,
var area: String,
var fecha:String,
var reuniones: List<NewReunion>?
){}
Now, to create 'reuniones' I have two classes, Reunion and NewReunion. The class that corresponds to create a MongoDB embedded document is NewReunion.
NewReunion.kt
#Document
data class Reunion(
val objetivo: String,
val fecha: String,
val participantes: List<Participante>?
) {}
#Document
data class NewReunion(
var id: String? = ObjectId().toHexString(),
var fecha: String,
var participantes: List<NewParticipante>?
) {}
This is where I have the problem. I want to generate an ObjectId for this NewReunion class, so that each object embedded in it has an id. The problem is that ObjectId ().ToHexString() is not generating any value at the time that the object of type NewReunion is built, but the other data that are objetivo and fecha are filled with the data that comes from the request POST.
How I send the information.
The information I send via POST. This request is handled by a Controller named ProyectoController.kt
ProyectoController.kt
#PostMapping("/")
fun createProyecto(#RequestBody newProyecto: NewProyecto): NewProyecto = proyectoService.createProyecto(newProyecto)
ProyectoRepository.kt
interface ProyectoRepository : MongoRepository<Proyecto, String> {
fun findById(id: ObjectId): Proyecto
override fun findAll(): List<Proyecto>
fun insert(proyecto: NewProyecto): NewProyecto
fun save(proyect: Proyecto): Proyecto
fun deleteById(id: ObjectId)
}
ProyectoService.kt
#Service("proyectoService")
class ProyectoServiceImpl : ProyectoService {
#Autowired
lateinit var proyectoRepository: ProyectoRepository
//Obtener un proyecto
override fun findById(id: ObjectId): Proyecto = proyectoRepository.findById(id)
//Obtener todos los proyectos
override fun findAll(): List<Proyecto> = proyectoRepository.findAll()
//Crear un proyecto
override fun createProyecto(newProyecto: NewProyecto): NewProyecto = proyectoRepository.insert(newProyecto)
//Actualizar un proyecto
override fun updateProyecto(proyecto: Proyecto):Proyecto = proyectoRepository.save(proyecto)
//Eliminar un proyecto
override fun deleteProyecto(id:ObjectId) = proyectoRepository.deleteById(id)
}
POST using Postman:
To send the information I am using Postman, and I send the request in the following way.
At the time of creating the new Proyecto, I return it to see the result which returns a result with id=null, but all other fields do assign the corresponding value:
Now, I tried initializing all the constructor parameters of the NewReunion class to see what happened.
data class NewReunion(
#Id
var id: String? = ObjectId().toHexString(),
var objetivo: String = "",
var fecha: String = ""
) {}
the value for the id is generated correctly together with the other values. It is just this behavior that I do not understand why I need to initialize constructor parameters of the NewReunion class.
Result of POST with the parameters initialized.
build.gradle
buildscript {
ext.kotlin_version = '1.2.71'
ext {
kotlinVersion = '1.2.71'
springBootVersion = '2.0.6.RELEASE'
}
repositories {
mavenCentral()
}
dependencies {
classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
classpath("org.jetbrains.kotlin:kotlin-gradle-plugin:${kotlinVersion}")
classpath("org.jetbrains.kotlin:kotlin-allopen:${kotlinVersion}")
classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
}
}
apply plugin: 'kotlin'
apply plugin: 'kotlin-spring'
apply plugin: 'eclipse-wtp'
apply plugin: 'org.springframework.boot'
apply plugin: 'io.spring.dependency-management'
apply plugin: 'war'
group = 'com.gibranlara'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = 1.8
compileKotlin {
kotlinOptions {
freeCompilerArgs = ["-Xjsr305=strict"]
jvmTarget = "1.8"
}
}
compileTestKotlin {
kotlinOptions {
freeCompilerArgs = ["-Xjsr305=strict"]
jvmTarget = "1.8"
}
}
repositories {
mavenCentral()
}
configurations {
providedRuntime
}
dependencies {
compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version" // Required for Kotlin integration
compile "org.jetbrains.kotlin:kotlin-reflect:$kotlin_version"
compile "org.springframework.boot:spring-boot-starter-data-mongodb"
compile 'org.springframework.boot:spring-boot-starter-web'
}
The library you are using is probably not written with Kotlin in mind.
Kotlin generates a synthetic constructor that loads default values prior to calling the actual constructor, e.g.
// Java
public NewReunion(String var1, String var2, String var3, int var4, DefaultConstructorMarker var5) {
if ((var4 & 1) != 0) {
var1 = ObjectId().toHexString();
}
this(var1, var2, var3);
}
The library is likely doing one of the following:
Calling the default constructor, then calling set[Property] matching the annotations/convention.
Calling the closest match constructor: NewReunion(#Nullable String id, #NotNull String objetivo, #NotNull String fecha) with NewReunion(null, "objetivo", "fecha")
If you define your class as such:
data class NewReunion #JvmOverloads constructor(
var id: String? = "",
var objetivo: String,
var fecha: String
)
You will get additional constructors e.g.
// Java
public NewReunion(#NotNull String objetivo, #NotNull String fecha)
If your library is using the first option then you may need to lazy initialize the id field in a getter (also convert data class to normal class).
An Aside
Most of these kind of problems stem from devs using the same object model for communication and business logic. Whenever I see a nullable id on an entity it like a clarion call that bugs are afoot.
Any data you get from an outside source(even if it's from a server you control) should be treated as if it was put there by your most baleful enemy, but many developers just suck it in and use it as it comes.
If you don't have something along the lines of
val cleanData = validate(inputData)
before crossing from an input layer to a business layer then you are setting yourself up for future embarrassment.
Input layers are:
User interface
Web services
Anything coming from outside your immediate domain of control
Well, I want to replace my String param from the following Play scala Route into my own object, say "MyObject"
From GET /api/:id controllers.MyController.get(id: String)
To GET /api/:id controllers.MyController.get(id: MyOwnObject)
Any idea on how to do this would be appreciated.
Well, I have written up my own "MyOwnObject" binder now. Another way of implementing PathBindable to bind an object.
object Binders {
implicit def pathBinder(implicit intBinder: PathBindable[String]) = new PathBindable[MyOwnObject] {
override def bind(key: String, value: String): Either[String, MyOwnObject] = {
for {
id <- intBinder.bind(key, value).right
} yield UniqueId(id)
}
override def unbind(key: String, id: UniqueId): String = {
intBinder.unbind(key, id.value)
}
}
}
Use PathBindable to bind parameters from path rather than from query. Sample implementation for binding ids from path separated by comma (no error handling):
public class CommaSeparatedIds implements PathBindable<CommaSeparatedIds> {
private List<Long> id;
#Override
public IdBinder bind(String key, String txt) {
if ("id".equals(key)) {
String[] split = txt.split(",");
id = new ArrayList<>(split.length + 1);
for (String s : split) {
long parseLong = Long.parseLong(s);
id.add(Long.valueOf(parseLong));
}
return this;
}
return null;
}
...
}
Sample path:
/data/entity/1,2,3,4
Sample routes entry:
GET /data/entity/:id controllers.EntityController.process(id: CommaSeparatedIds)
I'm not sure if it works for binding data in the path part of a URL, but you may want to read the docs on QueryStringBindable if you're able to accept your data as query params.