#4 DB-Integration in Server - Gerüst mit Exposed+HikariCP+Postgres steht

books/src/commonMain/kotlin/net/keinekekse/app/books/Version.kt

@@ -4,13 +4,13 @@ import net.keinekekse.version.Version
 
 object VERSION: Version {
     override val version = "1.0.0"
-    override val fullVersion = "1.0.0+build.221"
+    override val fullVersion = "1.0.0+build.222"
     override val major = 1
     override val minor = 0
     override val patch = 0
     override val preRelease = ""
-    override val buildMetadata = "build.221"
-    override val buildDate = "2026-02-06T22:31:36.863331Z"
+    override val buildMetadata = "build.222"
+    override val buildDate = "2026-02-07T16:26:28.842311Z"
     override val displayName = "Books App"
     override val copyright = "Copyright (c) 2026 Hartmut Bauer"
     override val name = "books"

gradle/libs.versions.toml

@@ -8,19 +8,20 @@ composeAppVersion = "1.0.0"
 androidx-lifecycle = "2.9.6"
 composeHotReload = "1.0.0"
 composeMultiplatform = "1.10.0"
+exposed = "1.0.0"
+hikari = "7.0.2"
 junit = "4.13.2"
 kotlin = "2.3.0"
 kotlin-wrappers-css = "2025.6.4"
 kotlinx-coroutines = "1.10.2"
 kotlinx-html = "0.12.0"
 koin-bom = "4.2.0-RC1"
+kotlinLogging = "7.0.14"
 koin-plugin = "0.3.0"
 ktor = "3.4.0"
-logback = "1.5.26"
-kotlinLogging = "7.0.14"
+logback = "1.5.28"
 material3 = "1.10.0-alpha05"
-settings = "1.3.0"
-dataStore = "1.2.0"
+postgres = "42.7.9"
 uiDesktop = "1.7.0"
 
 [libraries]
@@ -55,6 +56,9 @@ ktor-serverHtmlBuilder = { module = "io.ktor:ktor-server-html-builder", version.
 ktor-serverHtmx = { module = "io.ktor:ktor-server-htmx", version.ref = "ktor" }
 ktor-htmxHtml = { module = "io.ktor:ktor-htmx-html", version.ref = "ktor" }
 ktor-serverContentNegotiation = { module = "io.ktor:ktor-server-content-negotiation", version.ref = "ktor" }
+ktor-server-host-common = { module = "io.ktor:ktor-server-host-common-jvm", version.ref = "ktor" }
+ktor-server-status-pages = { module = "io.ktor:ktor-server-status-pages-jvm", version.ref = "ktor" }
+
 ktor-serverTestHost = { module = "io.ktor:ktor-server-test-host-jvm", version.ref = "ktor" }
 ktor-client = { module = "io.ktor:ktor-client-core", version.ref = "ktor" }
 ktor-clientAuth = { module = "io.ktor:ktor-client-auth", version.ref = "ktor" }
@@ -84,10 +88,11 @@ koin-test = { module = "io.insert-koin:koin-test" }
 #koin-compose-viewmodel-navigation3 = { module = "io.insert-koin:koin-compose-viewmodel-navigation3" }
 # ----
 
-# Settings vorerst ohne externe Hilfe
-#multiplatformSettings = { module = "com.russhwolf:multiplatform-settings", version.ref = "settings" }
-#androidx-datastore = { module = "androidx.datastore:datastore", version.ref = "dataStore" }
-#androidx-datastore-preferences = { module = "androidx.datastore:datastore-preferences", version.ref = "dataStore" }
+postgresql = { module = "org.postgresql:postgresql", version.ref = "postgres" }
+exposed-core = { module = "org.jetbrains.exposed:exposed-core", version.ref = "exposed" }
+exposed-jdbc = { module = "org.jetbrains.exposed:exposed-jdbc", version.ref = "exposed" }
+exposed-dao = { module = "org.jetbrains.exposed:exposed-dao", version.ref = "exposed" }
+hikaricp = { module = "com.zaxxer:HikariCP", version.ref = "hikari" }
 
 [bundles]
 kotlin-compose = [

server/build.gradle.kts

@@ -31,6 +31,8 @@ dependencies {
     implementation(libs.ktor.serverAuthJwt)
     implementation(libs.ktor.serverContentNegotiation)
     implementation(libs.ktor.serializationJson)
+    implementation(libs.ktor.server.host.common)
+    implementation(libs.ktor.server.status.pages)
 
     implementation(project.dependencies.platform(libs.koin.bom))
     implementation(libs.koin.logger.slf4j)
@@ -38,6 +40,12 @@ dependencies {
     implementation(libs.koin.ktor)
 //    implementation("io.insert-koin:koin-logger-slf4j:4.1.2-Beta1")
 
+    implementation(libs.postgresql)
+    implementation(libs.exposed.core)
+    implementation(libs.exposed.jdbc)
+    implementation(libs.exposed.dao)
+    implementation(libs.hikaricp)
+
     testImplementation(libs.ktor.serverTestHost)
     testImplementation(libs.kotlin.testJunit)
 }

server/buildnumber.properties

@@ -1,3 +1,3 @@
 #auto generated
-#Sat Feb 07 20:02:00 CET 2026
-build.number=27
+#Sun Feb 08 01:38:22 CET 2026
+build.number=35

server/src/main/kotlin/net/keinekekse/app/Application.kt

@@ -3,9 +3,13 @@ package net.keinekekse.app
 import io.github.oshai.kotlinlogging.KotlinLogging
 import io.ktor.server.application.*
 import net.keinekekse.app.server.VERSION
+import net.keinekekse.app.server.config.configureDatabase
 import net.keinekekse.app.server.config.configureKoin
 import net.keinekekse.app.server.config.configureRouting
 import net.keinekekse.app.server.config.configureSecurity
+import net.keinekekse.app.server.testdb.db.BookTable
+import org.jetbrains.exposed.v1.jdbc.SchemaUtils
+import org.jetbrains.exposed.v1.jdbc.transactions.transaction
 
 private val logger = KotlinLogging.logger {}
 
@@ -26,4 +30,10 @@ fun Application.module() {
     configureKoin()
     configureSecurity()
     configureRouting()
+    configureDatabase()
+
+    // create if not exists
+    transaction {
+        SchemaUtils.create(BookTable)
+    }
 }

server/src/main/kotlin/net/keinekekse/app/server/Version.kt

@@ -3,14 +3,14 @@ package net.keinekekse.app.server
 import net.keinekekse.version.Version
 
 object VERSION: Version {
-    override val version = "0.1.0-beta.1+build.27"
-    override val fullVersion = "0.1.0-beta.1+build.27"
+    override val version = "0.1.0-beta.1+build.35"
+    override val fullVersion = "0.1.0-beta.1+build.35"
     override val major = 0
     override val minor = 1
     override val patch = 0
     override val preRelease = "beta.1"
-    override val buildMetadata = "build.27"
-    override val buildDate = "2026-02-07T19:02:00.909145Z"
+    override val buildMetadata = "build.35"
+    override val buildDate = "2026-02-08T00:38:22.418116Z"
     override val displayName = "kAS"
     override val copyright = "Copyright (c) 2026 Hartmut Bauer"
     override val name = "server"

server/src/main/kotlin/net/keinekekse/app/server/config/database.kt

@@ -0,0 +1,47 @@
+package net.keinekekse.app.server.config
+
+import com.zaxxer.hikari.HikariConfig
+import com.zaxxer.hikari.HikariDataSource
+import io.ktor.server.application.*
+import org.jetbrains.exposed.v1.core.DatabaseConfig
+import org.jetbrains.exposed.v1.jdbc.Database
+
+fun Application.configureDatabase() {
+
+    val config = HikariConfig().apply {
+//        jdbcUrl = "jdbc:mysql://$host:$port/$db"
+        dataSourceClassName = "org.postgresql.ds.PGSimpleDataSource"
+        username = getKeyFromConfiguration("postgres.user")
+        password = getKeyFromConfiguration("postgres.password")
+
+        addDataSourceProperty("serverName", getKeyFromConfiguration("postgres.host", "localhost"))
+        addDataSourceProperty("portNumber", getKeyFromConfiguration("postgres.port", "5432"))
+        addDataSourceProperty(
+            "databaseName",
+            getKeyFromConfiguration("postgres.database", username)
+        )
+
+        maximumPoolSize = 6
+        isReadOnly = false
+        transactionIsolation = "TRANSACTION_SERIALIZABLE"
+    }
+
+    val dataSource = HikariDataSource(config)
+
+    Database.connect(
+        datasource = dataSource,
+        databaseConfig = DatabaseConfig {
+            // set other parameters here
+        }
+    )
+
+//    Class.forName("org.postgresql.Driver")
+//    val host = getKeyFromConfiguration("postgres.host", "localhost")
+//    val port = getKeyFromConfiguration("postgres.port", "5432")
+//    val user = getKeyFromConfiguration("postgres.user")
+//    val password = getKeyFromConfiguration("postgres.password")
+//    val database = getKeyFromConfiguration("postgres.database", user)
+//
+//    // "jdbc:postgresql://host:5432/database",
+//    return DriverManager.getConnection("jdbc:postgresql://$host:$port/$database", user, password)
+}

server/src/main/kotlin/net/keinekekse/app/server/config/getKeyFromConfiguration.kt

@@ -0,0 +1,10 @@
+package net.keinekekse.app.server.config
+
+import io.ktor.server.application.*
+
+fun Application.getKeyFromConfiguration(key: String, default: String? = null): String {
+    val value = environment.config.propertyOrNull(key)?.getString() ?: default
+    // ohne die Konfig-Params geht nix, hier ist nur noch Abbruch möglich
+    return value
+        ?: throw IllegalStateException("Configuration key '$key' not found, server start aborted.")
+}

server/src/main/kotlin/net/keinekekse/app/server/config/security.kt

@@ -6,7 +6,6 @@ import io.ktor.http.*
 import io.ktor.server.application.*
 import io.ktor.server.auth.*
 import io.ktor.server.auth.jwt.*
-import io.ktor.server.config.*
 import io.ktor.server.response.*
 import java.net.URI
 
@@ -14,25 +13,13 @@ private val logger = KotlinLogging.logger {}
 
 fun Application.configureSecurity() {
 
-    fun getFromConfig(key: String): String {
-        try {
-            return environment.config.property("ktor.conf.$key").getString()
-        } catch (e: ApplicationConfigurationException) {
-            // ohne die Konfig-Params geht nix (und defaults sind hier sinnlos), hier ist nur noch Abbruch möglich
-            throw IllegalStateException(
-                "Configuration key '$key' not found, server start aborted.",
-                e
-            )
-        }
-    }
-
     // Kommunikation funktioniert nur im internen Containernetzwerk,
     // d.h. Container- bzw. Pod-Name + interner Port
-    val keycloakInternalUrl = getFromConfig("keycloakInternalUrl")
-    val keycloakUrl = getFromConfig("keycloakUrl")
-    val keycloakRealm = getFromConfig("keycloakRealm")
-    val keycloakClientId = getFromConfig("keycloakClientId")
-    val keycloakCertUrl = getFromConfig("keycloakCertUrl")
+    val keycloakInternalUrl = getKeyFromConfiguration("keycloak.internalUrl")
+    val keycloakUrl = getKeyFromConfiguration("keycloak.url")
+    val keycloakRealm = getKeyFromConfiguration("keycloak.realm")
+    val keycloakClientId = getKeyFromConfiguration("keycloak.clientId")
+    val keycloakCertUrl = getKeyFromConfiguration("keycloak.certUrl")
 
     val certUrl = "$keycloakInternalUrl/$keycloakRealm/$keycloakCertUrl"
     val issuer = "$keycloakUrl/$keycloakRealm"

server/src/main/kotlin/net/keinekekse/app/server/testdb/db/BookDAO.kt

@@ -0,0 +1,25 @@
+package net.keinekekse.app.server.testdb.db
+
+import net.keinekekse.app.server.testdb.model.Book
+import org.jetbrains.exposed.v1.core.dao.id.EntityID
+import org.jetbrains.exposed.v1.core.dao.id.LongIdTable
+import org.jetbrains.exposed.v1.dao.LongEntity
+import org.jetbrains.exposed.v1.dao.LongEntityClass
+
+object BookTable : LongIdTable("book") {
+    var title = varchar("title", 50)
+    var author = varchar("author", 50)
+    var series = varchar("series", 50)
+    var seriesIndex = integer("seriesIndex")
+}
+
+class BookDAO(id: EntityID<Long>) : LongEntity(id) {
+    companion object : LongEntityClass<BookDAO>(BookTable)
+
+    var title by BookTable.title
+    var author by BookTable.author
+    var series by BookTable.series
+    var seriesIndex by BookTable.seriesIndex
+}
+
+fun daoToModel(dao: BookDAO) = Book(dao.title, dao.author, dao.series, dao.seriesIndex)

server/src/main/kotlin/net/keinekekse/app/server/testdb/model/Book.kt

@@ -0,0 +1,11 @@
+package net.keinekekse.app.server.testdb.model
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class Book(
+    var title: String = "",
+    var author: String = "",
+    var series: String = "",
+    var seriesIndex: Int = 0,
+)

server/src/main/kotlin/net/keinekekse/app/server/testdb/model/BookRepository.kt

@@ -0,0 +1,11 @@
+package net.keinekekse.app.server.testdb.model
+
+interface BookRepository {
+    suspend fun allBooks(): List<Book>
+    suspend fun bookById(id: Long): Book?
+    suspend fun booksBySeries(series: String): List<Book>
+    suspend fun bookByTitle(title: String): List<Book>
+    suspend fun bookByAuthor(author: String): List<Book>
+    suspend fun addTBook(book: Book)
+    suspend fun removeBook(id: Long): Boolean
+}

server/src/main/kotlin/net/keinekekse/app/server/testdb/model/BookRepositoryImpl.kt

@@ -0,0 +1,31 @@
+package net.keinekekse.app.server.testdb.model
+
+class BookRepositoryImpl : BookRepository {
+    override suspend fun allBooks(): List<Book> {
+        TODO("Not yet implemented")
+    }
+
+    override suspend fun bookById(id: Long): Book? {
+        TODO("Not yet implemented")
+    }
+
+    override suspend fun booksBySeries(series: String): List<Book> {
+        TODO("Not yet implemented")
+    }
+
+    override suspend fun bookByTitle(title: String): List<Book> {
+        TODO("Not yet implemented")
+    }
+
+    override suspend fun bookByAuthor(author: String): List<Book> {
+        TODO("Not yet implemented")
+    }
+
+    override suspend fun addTBook(book: Book) {
+        TODO("Not yet implemented")
+    }
+
+    override suspend fun removeBook(id: Long): Boolean {
+        TODO("Not yet implemented")
+    }
+}

server/src/main/resources/application.conf

@@ -18,18 +18,19 @@ ktor {
         # ApplicationKt.module() übernimmt die Konfiguration
         modules = [ net.keinekekse.app.ApplicationKt.module ]
     }
-    conf {
-        # eigene Parameter -> ktor.conf.<name>
-        #
-        keycloakInternalUrl = "http://kec:8080/realms"
-        keycloakUrl = "https://kec.keinekekse.net/realms"
-        keycloakRealm = "app-server-realm"
-        keycloakClientId = "pkce-book-app"
-        keycloakCertUrl = "protocol/openid-connect/certs"
+}
+keycloak {
+    internalUrl = "http://kec:8080/realms"
+    url = "https://kec.keinekekse.net/realms"
+    realm = "app-server-realm"
+    clientId = "pkce-book-app"
+    certUrl = "protocol/openid-connect/certs"
+}
+postgres {
     # DB-Params werden vom Container als env vars gesetzt
-        dbHost = ${DB_HOST}
-        dbPort = ${DB_PORT}
-        dbUser = ${DB_USER}
-        dbPassword = ${DB_PASSWORD}
-    }
+    host = ${DB_HOST}
+    port = ${DB_PORT}
+    database = ${DB_DATABASE}
+    user = ${DB_USER}
+    password = ${DB_PASSWORD}
 }