Ktor Workshop

Transcript

1. Hands-On Kotlin Web Development with Ktor
2. Leonid Stashevskii Ktor developer Anton Arhipov Developer Advocate @antonarhipov @_ _ _e5l
4. Part 1. Introduction & overview Part 2. Persistence with Exposed Part 3. Non-functional requirements Part 4. Extending Ktor Hands-On Kotlin Web Development with Ktor
5. Part 1. Introduction & overview Part 2. Persistence with Exposed Part 3. Non-functional requirements Part 4. Extending Ktor Hands-On Kotlin Web Development with Ktor Demonstration kitchensink
6. For each part, we will: Rules of the game: hands-on 1. Provide you with a starter project 2. Give you some time to add functionality 3. Provide a sample solution and walk you through the code
7. IntelliJ IDEA with Kotlin (and Ktor) plugins Setup Docker HTTP client Database client
8. https://github.com/antonarhipov/ktor-workshop Setup % git branch * main branch01 branch02 branch03 branch04 branch05 branch06 branch07 branch08
9. https://github.com/antonarhipov/ktor-workshop Setup % git branch * main branch01 branch02 branch03 branch04 branch05 branch06 branch07 branch08 Initial state, generated application First tests - empty First tests - implementation CRUD implementation Adding structure and DI Database access with Exposed - basics Database access with Exposed - adding relations Database access with Exposed - adding entities Integration testing with Testcontainers
10. Part 1. Introduction to Ktor
11. What web framework should I use with Kotlin?
12. Hexagon * There is more, of course!
13. ktor.io
17. import com.example.plugins.* import io.ktor.server.application.* import io.ktor.server.engine.* import io.ktor.server.netty.* fun main() { embeddedServer(Netty, port = 8080, host = "0.0.0.0", module = Application :: module) .start(wait = true) } fun Application.module() { configureRouting() }
18. import com.example.plugins.* import io.ktor.server.application.* import io.ktor.server.engine.* import io.ktor.server.netty.* fun main() { embeddedServer(Netty, port = 8080, host = "0.0.0.0", module = Application :: module) .start(wait = true) } fun Application.module() { routing { get("/") { call.respondText("Hello World!") } } }
19. import com.example.plugins.* import io.ktor.server.application.* import io.ktor.server.engine.* import io.ktor.server.netty.* fun main() { embeddedServer(Netty, port = 8080, host = "0.0.0.0", module = Application :: module) .start(wait = true) } fun Application.module() { routing { get("/") { call.respondText("Hello World!") } } } Start an embedded server with Netty engine on port 8080
20. import com.example.plugins.* import io.ktor.server.application.* import io.ktor.server.engine.* import io.ktor.server.netty.* fun main() { embeddedServer(Netty, port = 8080, host = "0.0.0.0", module = Application :: module) .start(wait = true) } fun Application.module() { routing { get("/") { call.respondText("Hello World!") } } } Adding routes
21. import com.example.plugins.* import io.ktor.server.application.* import io.ktor.server.engine.* import io.ktor.server.netty.* fun main() { embeddedServer(Netty, port = 8080, host = "0.0.0.0", module = Application :: module) .start(wait = true) } fun Application.module() { routing { get("/") { call.respondText("Hello World!") } } } Request mapping
22. import com.example.plugins.* import io.ktor.server.application.* import io.ktor.server.engine.* import io.ktor.server.netty.* fun main() { embeddedServer(Netty, port = 8080, host = "0.0.0.0", module = Application :: module) .start(wait = true) } fun Application.module() { routing { get("/") { call.respondText("Hello World!") } } } Write response
23. dependencies { implementation("io.ktor:ktor-server-core-jvm") implementation("io.ktor:ktor-server-netty-jvm") implementation("ch.qos.logback:logback-classic:$logback_version") testImplementation("io.ktor:ktor-server-tests-jvm") testImplementation("org.jetbrains.kotlin:kotlin-test-junit:$kotlin_version") }
25. Routing HTTP
26. Service Routing HTTP
27. Database Persistence Service Routing HTTP
28. Database Persistence Service Routing Model DAO Model DTO JSON HTTP
29. Database Persistence Service Routing Model DAO Model DTO HTTP JSON
30. Database Persistence Service Routing Model DAO Model DTO HTTP JSON
31. Database Persistence Service Routing Model DAO Model DTO HTTP JSON Libraries, DI, plugins, patterns, best practices, etc Grey area:
32. Database Persistence Service Routing Model DAO Model DTO HTTP JSON Coroutines Libraries, DI, plugins, patterns, best practices, etc Grey area:
33. Ktor's approach - explicitness
34. Ktor's approach - explicitness Fine-grained approach to dependencies "Dependency per plugin" Compatible with JPMS
35. TODO: more intro? No "magic". No plugin starts automatically
36. TODO: more intro? No "magic". No plugin starts automatically Use the install() function to con fi gure plugins
37. Hands-on time! Use the project generator to create new project. Add Routing, Content Negotiation, and kotlinx.serialization plugins. Run it!!! What do you see? Warmup
38. Hands-on time! Use the project generator to create new project. Add Routing, Content Negotiation, and kotlinx.serialization plugins. Run it!!! What do you see? Warmup Hint: if you select kotlinx.serialization at the plugins stage of the wizard, the other two will be selected automatically
39. Hands-on time! Use the project generator to create new project. Add Routing, Content Negotiation, and kotlinx.serialization plugins. * Run it!!! What do you see? * - Add more plugins if you like, of course!
40. Hands-on time! Use the project generator to create new project. Add Routing, Content Negotiation, and kotlinx.serialization plugins. Run it!!! What do you see? get("/") { call.respondText("Hello World!") } get("/json/kotlinx-serialization") { call.respond(mapOf("hello" to "world")) }
41. Hands-on time! Use the project generator to create new project. Add Routing, Content Negotiation, and kotlinx.serialization plugins. Run it!!! What do you see? https: // github.com/antonarhipov/ktor-workshop % git branch * main branch01 branch02 branch03
42. Hands-on time! Use the project generator to create new project. Add Routing, Content Negotiation, and kotlinx.serialization plugins. Run it!!! What do you see? https: // github.com/antonarhipov/ktor-workshop % git branch * main branch01 branch02 branch03 This is our starting point
43. Hands-on time! Implement endpoints for CRUD operations for the User data class. @Serializable data class User( val userId: Int, val userType: UserType, val displayName: String, val link: String, val aboutMe: String? = null ) enum class UserType { REGISTERED, MODERATOR, }
44. Hands-on time! Implement endpoints for CRUD operations for the User data class. @Serializable data class User( val userId: Int, val userType: UserType, val displayName: String, val link: String, val aboutMe: String? = null ) enum class UserType { REGISTERED, MODERATOR, } Tests
45. import kotlin.test.* class ApplicationTest { @Test fun testRoot() = testApplication { application { routing { get("/") { call.respondText("Hello World!") } } } client.get("/").apply { assertEquals(HttpStatusCode.OK, status) assertEquals("Hello World!", bodyAsText()) } } } Creates a TestApplication
46. import kotlin.test.* class ApplicationTest { @Test fun testRoot() = testApplication { application { routing { get("/") { call.respondText("Hello World!") } } } client.get("/").apply { assertEquals(HttpStatusCode.OK, status) assertEquals("Hello World!", bodyAsText()) } } } De fi ne functionality to be tested
47. import kotlin.test.* class ApplicationTest { @Test fun testRoot() = testApplication { application { routing { get("/") { call.respondText("Hello World!") } } } client.get("/").apply { assertEquals(HttpStatusCode.OK, status) assertEquals("Hello World!", bodyAsText()) } } } Use client instance interaction with the TestApplication
48. import kotlin.test.* class ApplicationTest { @Test fun testRoot() = testApplication { application { routing { get("/") { call.respondText("Hello World!") } } } client.get("/").apply { assertEquals(HttpStatusCode.OK, status) assertEquals("Hello World!", bodyAsText()) } } }
49. import kotlin.test.* class ApplicationTest { @Test fun testRoot() = testApplication { application { routing { get("/") { call.respondText("Hello World!") } } } client.get("/").apply { assertEquals(HttpStatusCode.OK, status) assertEquals("Hello World!", bodyAsText()) } } } It creates an application instance for each test. What if we want to reuse the application instance for several tests?
50. class ApplicationTest { val testApp = TestApplication { application { ... } } val client = testApp.createClient {} @Test fun testRoot() = runBlocking<Unit> { val response = client.get("/") assertEquals(HttpStatusCode.OK, response.status) assertEquals("Hello World!", response.bodyAsText()) } }
51. class ApplicationTest { val testApp = TestApplication { application { ... } } val client = testApp.createClient {} @Test fun testRoot() = runBlocking<Unit> { val response = client.get("/") assertEquals(HttpStatusCode.OK, response.status) assertEquals("Hello World!", response.bodyAsText()) } } Alternatively, create TestApplication instance
52. class ApplicationTest { val testApp = TestApplication { application { ... } } val client = testApp.createClient {} @Test fun testRoot() = runBlocking<Unit> { val response = client.get("/") assertEquals(HttpStatusCode.OK, response.status) assertEquals("Hello World!", response.bodyAsText()) } } Con fi gure HttpClient for the TestApplication
53. class ApplicationTest { val testApp = TestApplication { application { ... } } val client = testApp.createClient {} @Test fun testRoot() = runBlocking<Unit> { val response = client.get("/") assertEquals(HttpStatusCode.OK, response.status) assertEquals("Hello World!", response.bodyAsText()) } } Need to use runBlocking to run in a coroutine scope
54. class ApplicationTest { val testApp = TestApplication { application { ... } } val client = testApp.createClient { install(io.ktor.client.plugins.contentnegotiation.ContentNegotiation) { json() } } @Test fun testRoot() = runBlocking<Unit> { . .. ContentNegotiation needs to be con fi gured for the HttpClient
55. class ApplicationTest { val testApp = TestApplication { application { ... } } val client = testApp.createClient { install(io.ktor.client.plugins.contentnegotiation.ContentNegotiation) { json() } } @Test fun testRoot() = runBlocking<Unit> { . .. ContentNegotiation needs to be con fi gured for the HttpClient
56. HttpClient val response: HttpResponse = client.get("/data") assertEquals(HttpStatusCode.OK, response.status) assertEquals( ... , response.bodyAsText()) private val testApp = TestApplication { .. . } private val client = testApp.createClient { ... } Make request, check response https://ktor.io/docs/client-requests.html
57. HttpClient private val testApp = TestApplication { .. . } private val client = testApp.createClient { ... } val data = Json.decodeFromString<List<User >> (bodyAsText()) assertEquals( ... , data.size) Deserialize response body into objects val response: HttpResponse = client.get("/data") assertEquals(HttpStatusCode.OK, response.status) assertEquals( ... , response.bodyAsText()) Make request, check response https://ktor.io/docs/client-requests.html
58. HttpClient private val testApp = TestApplication { .. . } private val client = testApp.createClient { ... } val data = Json.decodeFromString<List<User >> (bodyAsText()) assertEquals( ... , data.size) Deserialize response body into objects val response: HttpResponse = client.get("/data") assertEquals(HttpStatusCode.OK, response.status) assertEquals( ... , response.bodyAsText()) Make request, check response val response = client.post("/data") { contentType(ContentType.Application.Json) setBody( ... ) } POST with HttpRequestBuilder https://ktor.io/docs/client-requests.html
59. Hands-on time! Implement endpoints for CRUD operations @Serializable data class User( val userId: Int, val userType: UserType, val displayName: String, val link: String, val aboutMe: String? = null ) enum class UserType { REGISTERED, MODERATOR, }
60. Hands-on time! Implement endpoints for CRUD operations @Test fun `get all data`(): Unit = runBlocking { ... } @Test fun `post data instance`(): Unit = runBlocking { ... } @Test fun `put data instance`(): Unit = runBlocking { ... } @Test fun `delete data instance`(): Unit = runBlocking { ... } @Serializable data class User( val userId: Int, val userType: UserType, val displayName: String, val link: String, val aboutMe: String? = null ) enum class UserType { REGISTERED, MODERATOR, } Implement these tests git branch * branch01
61. git branch * branch02
62. Let's take a look at the solution
63. https://ktor.io/docs/server-requests.html Receiving requests & sending responses https://ktor.io/docs/server-responses.html
64. Sending responses get("/") { call.respondText("Hello World!") } Respond something
65. Sending responses get("/") { call.respondText("Hello World!") } post("/") { val user = call.receive<User>() ... call.respond(status = HttpStatusCode.Created, message = "Data added successfully") } Respond with HTTP code Add response content
66. Receiving requests get("/") { call.respondText("Hello World!") } post("/") { val user = call.receive<User>() ... call.respond(status = HttpStatusCode.Created, message = "Data added successfully") } Deserialize request content
67. Receiving requests get("/") { call.respondText("Hello World!") } post("/") { val user = call.receive<User>() ... call.respond(status = HttpStatusCode.Created, message = "Data added successfully") } get("/{userId}") { val userId = call.parameters["userId"] ... } Access request parameters
68. Hands-on time! Implement endpoints for CRUD operations for the User data class. @Serializable data class User( val userId: Int, val userType: UserType, val displayName: String, val link: String, val aboutMe: String? = null ) enum class UserType { REGISTERED, MODERATOR, } routing { route("/users") { get { ... } post { .. . } get("/{userId}") { . .. } put("/{userId}") { . .. } delete("/{userId}") { ... } } } Hint
69. git branch * branch03
70. Let's take a look at the solution git branch * branch03
71. Structuring the project https://ktor.io/docs/server-application-structure.html
72. Dependency injection
75. implementation("io.insert-koin:koin-ktor:$koin_version") implementation("io.insert-koin:koin-logger-slf4j:$koin_version") Adding Koin build.gradle.kts
76. implementation("io.insert-koin:koin-ktor:$koin_version") implementation("io.insert-koin:koin-logger-slf4j:$koin_version") Adding Koin build.gradle.kts In Ktor app: install(Koin) { slf4jLogger() modules(usersDataModule) }
77. implementation("io.insert-koin:koin-ktor:$koin_version") implementation("io.insert-koin:koin-logger-slf4j:$koin_version") Adding Koin build.gradle.kts In Ktor app: install(Koin) { slf4jLogger() modules(usersDataModule) } val usersDataModule = module { single<IRepository> { RepositoryImpl() } }
78. implementation("io.insert-koin:koin-ktor:$koin_version") implementation("io.insert-koin:koin-logger-slf4j:$koin_version") Adding Koin build.gradle.kts In Ktor app: install(Koin) { slf4jLogger() modules(usersDataModule) } val usersDataModule = module { single<IRepository> { RepositoryImpl() } } fun Application.configureRouting() { val repository by inject<IRepository>()
79. Hands-on time! Add Koin (or KodeinDI) dependencies to the project: implementation("io.insert-koin:koin-ktor:$koin_version") implementation("io.insert-koin:koin-logger-slf4j:$koin_version")
80. Hands-on time! Abstract the repository implementation with an interface (UserRepository) Inject the repository implementation (UserRepositoryImpl) using Koin Don't forget to adjust the tests code! Add Koin (or KodeinDI) dependencies to the project: implementation("io.insert-koin:koin-ktor:$koin_version") implementation("io.insert-koin:koin-logger-slf4j:$koin_version")
81. Hands-on time! Abstract the repository implementation with an interface (UserRepository) Inject the repository implementation (UserRepositoryImpl) using Koin Don't forget to adjust the tests code! class UsersRepositoryImpl : UsersRepository { override fun findAll(): List<User> { TODO("Not yet implemented") } ... git branch * branch04 Add Koin (or KodeinDI) dependencies to the project: implementation("io.insert-koin:koin-ktor:$koin_version") implementation("io.insert-koin:koin-logger-slf4j:$koin_version")
82. Let's take a look at the solution
83. Part 2. Persistence with Exposed
84. What database framework should I use with Kotlin (and Ktor)?
85. SQLDelight
86. https://github.com/JetBrains/Exposed
87. Adding Exposed: dependencies build.gradle.kts val exposed_version = "0.50.1" implementation("org.jetbrains.exposed:exposed-core:$exposed_version") implementation("org.jetbrains.exposed:exposed-jdbc:$exposed_version") implementation("org.jetbrains.exposed:exposed-dao:$exposed_version") implementation("org.jetbrains.exposed:exposed-kotlin-datetime:$exposed_version")
88. Using Exposed: connecting to DB val database = Database.connect( url = "jdbc:h2:mem:test;DB_CLOSE_DELAY=-1", user = "root", driver = "org.h2.Driver", password = "" )
89. val database = Database.connect( HikariDataSource(HikariConfig().apply { jdbcUrl = "jdbc:h2:mem:test;DB_CLOSE_DELAY=-1" username = "root" driverClassName = "org.h2.Driver" password = "" }) ) Using Exposed: connecting to DB
90. val database = Database.connect( HikariDataSource(HikariConfig().apply { jdbcUrl = "jdbc:h2:mem:test;DB_CLOSE_DELAY=-1" username = "root" driverClassName = "org.h2.Driver" password = "" }) ) Using Exposed: connecting to DB transaction(database) { SchemaUtils.createMissingTablesAndColumns(Datum) }
91. val database = Database.connect( HikariDataSource(HikariConfig().apply { if (embedded) { username = "root" password = "" driverClassName = "org.h2.Driver" jdbcUrl = "jdbc:h2:mem:test;DB_CLOSE_DELAY=-1" } else { username = "test" password = "test" driverClassName = "org.postgresql.Driver" jdbcUrl = "jdbc:postgresql: // localhost:5432/test" } } )) Using Exposed: connecting to DB Check branch05, Database.kt
92. @Serializable data class Data(val id: Int, val text: String) object Datum : Table("data") { val id = integer("id").autoIncrement() val text = varchar("text", 255) }
93. @Serializable data class Data(val id: Int, val text: String) object Datum : Table("data") { val id = integer("id").autoIncrement() val text = varchar("text", 255) } Datum.selectAll().map { Data(it[Datum.id], it[Datum.text]) } Select and map
94. @Serializable data class Data(val id: Int, val text: String) object Datum : Table("data") { val id = integer("id").autoIncrement() val text = varchar("text", 255) } Datum.selectAll().map { Data(it[Datum.id], it[Datum.text]) } Datum.selectAll().where { Datum.id eq id }.singleOrNull() ? . let { Data(it[Datum.id], it[Datum.text]) } Select and map
95. @Serializable data class Data(val id: Int, val text: String) object Datum : Table("data") { val id = integer("id").autoIncrement() val text = varchar("text", 255) } Datum.selectAll().map { Data(it[Datum.id], it[Datum.text]) } Datum.selectAll().where { Datum.id eq id }.singleOrNull() ? . let { Data(it[Datum.id], it[Datum.text]) } Datum.insert { it[Datum.id] = data.id it[Datum.text] = data.text } Datum.update({ Datum.id eq data.id }) { it[Datum.text] = data.text } update / insert
96. Hands-on time! 1. Add Exposed dependencies to the project val exposed_version = "0.50.1" implementation("org.jetbrains.exposed:exposed-core:$exposed_version") implementation("org.jetbrains.exposed:exposed-jdbc:$exposed_version") implementation("org.jetbrains.exposed:exposed-dao:$exposed_version") implementation("org.jetbrains.exposed:exposed-kotlin-datetime:$exposed_version") https://github.com/JetBrains/exposed
97. Hands-on time! 2. De fi ne table objects for the data classes 1. Add Exposed dependencies to the project val exposed_version = "0.50.1" implementation("org.jetbrains.exposed:exposed-core:$exposed_version") implementation("org.jetbrains.exposed:exposed-jdbc:$exposed_version") implementation("org.jetbrains.exposed:exposed-dao:$exposed_version") implementation("org.jetbrains.exposed:exposed-kotlin-datetime:$exposed_version") https://github.com/JetBrains/exposed
98. Hands-on time! 2. De fi ne table objects for the data classes 3. Implement UserRepository using Exposed with the real database 1. Add Exposed dependencies to the project val exposed_version = "0.50.1" implementation("org.jetbrains.exposed:exposed-core:$exposed_version") implementation("org.jetbrains.exposed:exposed-jdbc:$exposed_version") implementation("org.jetbrains.exposed:exposed-dao:$exposed_version") implementation("org.jetbrains.exposed:exposed-kotlin-datetime:$exposed_version") https://github.com/JetBrains/exposed
99. Hands-on time! 2. De fi ne table objects for the data classes 3. Implement UserRepository using Exposed with the real database 1. Add Exposed dependencies to the project 4. Integrate the new implementation into Ktor application using DI val exposed_version = "0.50.1" implementation("org.jetbrains.exposed:exposed-core:$exposed_version") implementation("org.jetbrains.exposed:exposed-jdbc:$exposed_version") implementation("org.jetbrains.exposed:exposed-dao:$exposed_version") implementation("org.jetbrains.exposed:exposed-kotlin-datetime:$exposed_version") https://github.com/JetBrains/exposed
100. Let's take a look at the solution git branch * branch05
101. Table relations 1 N
102. id: integer text: varchar id: integer name: varchar data_ref: integer Data Item
103. object Datum : Table("data_table") { val id = integer("id").autoIncrement() val text = varchar("text", 255) override val primaryKey = PrimaryKey(id) } object Items : Table("items_table") { val id = integer("id").autoIncrement() val name = varchar("name", 255) val datum_ref = reference("datum_ref", Datum.id) override val primaryKey = PrimaryKey(id) }
104. object Datum : Table("data_table") { val id = integer("id").autoIncrement() val text = varchar("text", 255) override val primaryKey = PrimaryKey(id) } object Items : Table("items_table") { val id = integer("id").autoIncrement() val name = varchar("name", 255) val datum_ref = reference("datum_ref", Datum.id) override val primaryKey = PrimaryKey(id) }
105. val dataId = Datum.insert { it[Datum.text] = data.text } get Datum.id Items.insert { it[Items.name] = item.name it[Items.datum_ref] = dataId }
106. val dataId = Datum.insert { it[Datum.text] = data.text } get Datum.id Items.insert { it[Items.name] = item.name it[Items.datum_ref] = dataId } val item = Item("Some item") val data = Data("Some data")
107. Hands-on time! Update the UserRepository implementation to handle the relation object ContentTable : Table("content") { ... val author = reference("author_id", UserTable.id) Update data classes and application code
108. Let's take a look at the solution git branch * branch06
109. Exposed entities
110. object Datum : Table("data_table") { val id = integer("id").autoIncrement() val text = varchar("text", 255) override val primaryKey = PrimaryKey(id) } object Items : Table("items_table") { val id = integer("id").autoIncrement() val name = varchar("name", 255) val datum_ref = reference("datum_ref", Datum.id) override val primaryKey = PrimaryKey(id) }
111. object Datum : LongIdTable("data_table") { val id = integer("id").autoIncrement() val text = varchar("text", 255) override val primaryKey = PrimaryKey(id) } object Items : Table("items_table") { val id = integer("id").autoIncrement() val name = varchar("name", 255) val datum_ref = reference("datum_ref", Datum.id) override val primaryKey = PrimaryKey(id) }
112. object Datum : LongIdTable("data_table") { val id = integer("id").autoIncrement() val text = varchar("text", 255) override val primaryKey = PrimaryKey(id) } object Items : IdTable<Int>("items_table") { override val id = integer("id").autoIncrement().entityId() val name = varchar("name", 255) val datum_ref = reference("datum_ref", Datum.id) override val primaryKey = PrimaryKey(id) }
113. class DataEntity(id: EntityID<Long>) : LongEntity(id) { var text by DatumEntityTable.text companion object : LongEntityClass<DataEntity>(DatumEntityTable) } Defining entities
114. class DataEntity(id: EntityID<Long>) : LongEntity(id) { var text by DatumEntityTable.text companion object : LongEntityClass<DataEntity>(DatumEntityTable) } class ItemsEntity(id: EntityID<Int>) : IntEntity(id) { var name by ItemsEntityTable.name companion object : IntEntityClass<ItemsEntity>(ItemsEntityTable) } Defining entities
115. class DataEntity(id: EntityID<Long>) : LongEntity(id) { var text by DatumEntityTable.text companion object : LongEntityClass<DataEntity>(DatumEntityTable) } class ItemsEntity(id: EntityID<Int>) : IntEntity(id) { var name by ItemsEntityTable.name var data_ref by DataEntity referencedOn ItemsEntityTable.datum_ref companion object : IntEntityClass<ItemsEntity>(ItemsEntityTable) } Defining entities
116. val date = DataEntity.new { text = "Some text" } ItemsEntity.new { name = "Some item" data_ref = date } Operations with entities
117. val date = DataEntity.new { text = "Some text" } ItemsEntity.new { name = "Some item" data_ref = date } Operations with entities DataEntity.find { DatumEntityTable.text like "A%" }.toList()
118. class DataEntity(id: EntityID<Long>) : LongEntity(id) { var text by DatumEntityTable.text companion object : LongEntityClass<DataEntity>(DatumEntityTable) } class ItemsEntity(id: EntityID<Int>) : IntEntity(id) { var name by ItemsEntityTable.name var data_ref by DataEntity referencedOn ItemsEntityTable.datum_ref companion object : IntEntityClass<ItemsEntity>(ItemsEntityTable) } Defining entities
119. class DataEntity(id: EntityID<Long>) : LongEntity(id) { var text by DatumEntityTable.text val items by ItemsEntity referrersOn ItemsEntityTable.datum_ref companion object : LongEntityClass<DataEntity>(DatumEntityTable) } class ItemsEntity(id: EntityID<Int>) : IntEntity(id) { var name by ItemsEntityTable.name var data_ref by DataEntity referencedOn ItemsEntityTable.datum_ref companion object : IntEntityClass<ItemsEntity>(ItemsEntityTable) } Defining entities
120. DataEntity.find { DatumEntityTable.text like "A%" } .singleOrNull() ?. let { data -> DataInfo( text = data.text, items = data.items.map { ItemInfo(it.name) } ) } Operations with entities
121. DataEntity.find { DatumEntityTable.text like "A%" } .singleOrNull() ?. let { data -> DataInfo( text = data.text, items = data.items.map { ItemInfo(it.name) } ) } Operations with entities val selectedData = Datum.selectAll() .where { Datum.text like "A%" } .singleOrNull() ?. let { Data( text = it[Datum.text], items = Items.selectAll().where { Items.datum_ref eq it[Datum.id] }.map { Item(it[Items.name]) } ) } DAO vs DSL
122. Hands-on time! Implement a new repository with Exposed entities Integrate into Ktor app
123. Let's take a look at the solution git branch * branch07
124. Testcontainers
125. Hands-on time! Implement Testcontainers tests
126. Let's take a look at the solution git branch * branch08
127. Part 3. Non-functional requirements
128. Authentication, JWT git branch * branch09
129. WebSockets
130. More features & plugins status pages request validation static content type safe routing default headers, CORS CallLogging, CallId, MDC Logging & monitoring Docker image GraalVM native image
131. if when try Part 4. Extending Ktor
132. https://ktor.io/docs/server-custom-plugins.html
133. @JetBrainsKtor https://github.com/ktorio