Discover Your Ideal Airbnb: Implementing a Spring Boot & Atlas Search With Kotlin Sync Driver

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[
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  {
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    $search: {
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      index: "searchPlaces",
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      compound: {
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        filter: [
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          {
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            range: {
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              path: "number_of_reviews",
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              gte: 50
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            }
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          },
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          {
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            text: {
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              path: "summary",
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              query: "Istambun",
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              fuzzy: {
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                maxEdits: 2
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              }
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            }
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          }
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        ]
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      }
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    }
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  },
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  {
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    $limit: 5
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  },
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  {
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    $project: {
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      _id: 0,
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      name: 1,
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      summary: 1,
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      number_of_reviews: 1,
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      price: 1,    
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      street: "$address.street",
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    }
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  }
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]

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dependencies {
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 implementation("org.mongodb:mongodb-driver-kotlin-sync:5.1.1")
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} 

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spring.application.name=Airbnb Searcher
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spring.data.mongodb.uri=mongodb+srv://user:pass@cluster0.cluster.mongodb.net/
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spring.data.mongodb.database=sample_airbnb

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package com.mongodb.searcher.application.config
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import com.mongodb.kotlin.client.MongoClient
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import com.mongodb.kotlin.client.MongoDatabase
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import org.springframework.beans.factory.annotation.Value
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import org.springframework.context.annotation.Bean
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import org.springframework.context.annotation.Configuration
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@Configuration
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class MongoConfig {
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   @Value("\${spring.data.mongodb.uri}")
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   lateinit var uri: String
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   @Value("\${spring.data.mongodb.database}")
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   lateinit var databaseName: String
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   @Bean
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   fun getMongoClient(): MongoClient {
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       return MongoClient.create(uri)
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   }
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   @Bean
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   fun mongoDatabase(mongoClient: MongoClient): MongoDatabase {
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       return mongoClient.getDatabase(databaseName)
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   }
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}

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package com.mongodb.searcher.resources
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import com.mongodb.searcher.domain.Airbnb
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import org.bson.codecs.pojo.annotations.BsonId
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import org.bson.codecs.pojo.annotations.BsonProperty
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import org.bson.types.Decimal128
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data class AirbnbEntity(
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   @BsonId val id: String,
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   val name: String,
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   val summary: String,
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   val price: Decimal128,
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   @BsonProperty("number_of_reviews")
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   val numbersOfReviews: Int,
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   val address: Address
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) {
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   data class Address(
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       val street: String,
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       val country: String,
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       @BsonProperty("country_code")
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       val countryCode: String
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   )
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   fun toDomain(): Airbnb {
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       return Airbnb(
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           id = id,
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           name = name,
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           summary = summary,
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           price = price,
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           numbersOfReviews = numbersOfReviews,
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           street = address.street
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       )
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   }
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}

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package com.mongodb.searcher.resources
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import com.mongodb.client.model.Aggregates
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import com.mongodb.client.model.Projections
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import com.mongodb.client.model.search.FuzzySearchOptions
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import com.mongodb.client.model.search.SearchOperator
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import com.mongodb.client.model.search.SearchOptions
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import com.mongodb.client.model.search.SearchPath
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import com.mongodb.kotlin.client.MongoDatabase
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import org.slf4j.LoggerFactory
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import org.springframework.stereotype.Repository
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@Repository
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class AirbnbRepository(
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   private val mongoDatabase: MongoDatabase
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) {
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   companion object {
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       private val logger = LoggerFactory.getLogger(AirbnbRepository::class.java)
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       private const val COLLECTION = "listingsAndReviews"
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   }
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   fun find(query: String, minNumberReviews: Int): List<AirbnbEntity> {
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       val collection = mongoDatabase.getCollection<AirbnbEntity>(COLLECTION)
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       return try {
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           collection.aggregate(
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               listOf(
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                   createSearchStage(query, minNumberReviews),
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                   createLimitStage(),
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                   createProjectionStage()
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               )
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           ).toList()
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       } catch (e: Exception) {
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           logger.error("An exception occurred when trying to aggregate the collection: ${e.message}")
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           emptyList()
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       }
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   }
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   private fun createSearchStage(query: String, minNumberReviews: Int) =
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       Aggregates.search(
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           SearchOperator.compound().filter(
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               listOf(
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                   SearchOperator.numberRange(SearchPath.fieldPath("number_of_reviews"))
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                       .gte(minNumberReviews),
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                   SearchOperator.text(SearchPath.fieldPath(AirbnbEntity::summary.name), query)
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                       .fuzzy(FuzzySearchOptions.fuzzySearchOptions().maxEdits(2))
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               )
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           ),
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           SearchOptions.searchOptions().index("searchPlaces")
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       )
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   private fun createLimitStage() =
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       Aggregates.limit(5)
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   private fun createProjectionStage() =
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       Aggregates.project(
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           Projections.fields(
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               Projections.include(
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                   listOf(
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                       AirbnbEntity::name.name,
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                       AirbnbEntity::id.name,
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                       AirbnbEntity::summary.name,
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                       AirbnbEntity::price.name,
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                       "number_of_reviews",
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                       AirbnbEntity::address.name
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                   )
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               )
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           )
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       )
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}

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package com.mongodb.searcher.domain
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import org.bson.codecs.pojo.annotations.BsonId
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import org.bson.codecs.pojo.annotations.BsonProperty
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import org.bson.types.Decimal128
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data class Airbnb(
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   @BsonId val id: String,
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   val name: String,
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   val summary: String,
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   val price: Decimal128,
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   @BsonProperty("number_of_reviews")
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   val numbersOfReviews: Int,
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   val street: String
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)

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package com.mongodb.searcher.domain
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import com.mongodb.searcher.resources.AirbnbRepository
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import org.springframework.stereotype.Service
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@Service
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class AirbnbService(
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   private val airbnbRepository: AirbnbRepository
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) {
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   fun find(query: String, minNumberReviews: Int): List<Airbnb> {
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       require(query.isNotEmpty()) { "Query must not be empty" }
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       require(minNumberReviews > 0) { "Minimum number of reviews must not be negative" }
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      return airbnbRepository.find(query, minNumberReviews).map { it.toDomain() }
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   }
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}

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package com.mongodb.searcher.application.web
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import com.mongodb.searcher.domain.Airbnb
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import com.mongodb.searcher.domain.AirbnbService
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import org.springframework.web.bind.annotation.GetMapping
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import org.springframework.web.bind.annotation.RequestParam
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import org.springframework.web.bind.annotation.RestController
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@RestController
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class AirbnbController(
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   private val airbnbService: AirbnbService
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) {
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   @GetMapping("/airbnb/search")
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   fun find(
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       @RequestParam("query") query: String,
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       @RequestParam("minNumberReviews") minNumberReviews: Int
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   ): List<Airbnb> {
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       return airbnbService.find(query, minNumberReviews)
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   }
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}

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./gradlew bootRun

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curl --location 'http://localhost:8080/airbnb/search?query=Istambun&minNumberReviews=50'