Authentication aufräumen, 3. Schritt Error Handling f. auth + HttpClient

books/buildnumber.properties

@@ -1,3 +1,3 @@
 #auto generated
-#Thu Feb 12 03:10:51 CET 2026
-build.number=238
+#Thu Feb 12 22:52:33 CET 2026
+build.number=251

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

@@ -17,7 +17,7 @@ import androidx.compose.ui.tooling.preview.Preview
 import io.github.oshai.kotlinlogging.KotlinLogging
 import io.ktor.client.*
 import io.ktor.client.request.*
-import io.ktor.client.statement.*
+import io.ktor.http.*
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
@@ -25,6 +25,9 @@ import net.keinekekse.app.auth.AuthResult
 import net.keinekekse.app.auth.Authenticator
 import net.keinekekse.app.books.generated.resources.Res
 import net.keinekekse.app.books.generated.resources.compose_multiplatform
+import net.keinekekse.app.books.model.Book
+import net.keinekekse.app.service.ApiResponse
+import net.keinekekse.app.service.safeRequest
 import org.jetbrains.compose.resources.painterResource
 import org.koin.compose.koinInject
 import org.koin.core.annotation.Single
@@ -44,6 +47,9 @@ fun App() {
         val test = koinInject<TestAuth>()
         val authenticator = koinInject<Authenticator>()
         var showContent by remember { mutableStateOf(false) }
+        // externer StateFlow
+        val logonState by remember { authenticator.logonState }.collectAsState()
+
         Column(
             modifier = Modifier
                 .background(MaterialTheme.colorScheme.primaryContainer)
@@ -74,8 +80,7 @@ fun App() {
                     Text("Compose: $greeting")
                 }
             }
-            // refresh fkt. nicht!
-            when (authenticator.logonState.value) {
+            when (logonState) {
                 is AuthResult.Success -> {
                     Text("Anmeldung erfolgreich")
                 }
@@ -99,16 +104,45 @@ fun App() {
 class TestAuth(val httpClient: HttpClient) {
 
     private val srv = "https://kas.keinekekse.net"
+
     suspend fun request(url: String) {
-        logger.debug { "connecting" }
-//        val response = httpClient.get(srv + "testdb/books")
+        logger.debug { "TestAuth: connecting $srv$url" }
+
+        val response: ApiResponse<List<Book>, Any> = httpClient.safeRequest {
+            url(Url(srv + url))
+            method = HttpMethod.Get
+        }
+        when (response) {
+            is ApiResponse.Success -> {
+                logger.debug { "TestAuth: success" }
+                val books = response.body
+                for (book in books) {
+                    logger.debug { book }
+                }
+            }
+
+            is ApiResponse.ErrorResponse -> {
+                when (response) {
+                    is ApiResponse.ErrorResponse.HttpError -> logger.debug { "TestAuth: HTTP error ${response.code} - ${response.errorBody}" }
+                    is ApiResponse.ErrorResponse.NetworkError -> logger.debug { "TestAuth: Network error ${response.exception}" }
+                    is ApiResponse.ErrorResponse.SerializationError -> logger.debug { "TestAuth: Serialization error" }
+                }
+
+            }
+        }
 //        val books: List<Book> = response.body()
 
-        val response = httpClient.get(srv + url)
-        val body = response.bodyAsText()
+//        var response: HttpResponse? = null
+//        var body = ""
+//        try {
+//            response = httpClient.get(srv + url)
+//            body = response.bodyAsText()
+//        } catch (e: Throwable) {
+//            val error = e.toString()
+//            val status = response?.status
+//            val body = response?.bodyAsText() ?: ""
+//            logger.error(e) { "TestAuth: error $error ($body) [$status]" }
+//        }
 
-        logger.debug { "call to $url" }
-        logger.debug { response.status }
-        logger.debug { body }
     }
 }

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.238"
+    override val fullVersion = "1.0.0+build.251"
     override val major = 1
     override val minor = 0
     override val patch = 0
     override val preRelease = ""
-    override val buildMetadata = "build.238"
-    override val buildDate = "2026-02-12T02:10:51.539449Z"
+    override val buildMetadata = "build.251"
+    override val buildDate = "2026-02-12T21:52:33.708217Z"
     override val displayName = "Books App"
     override val copyright = "Copyright (c) 2026 Hartmut Bauer"
     override val name = "books"

shared/src/commonMain/kotlin/net/keinekekse/app/service/HttpClient.kt

@@ -2,12 +2,17 @@ package net.keinekekse.app.service
 
 import io.github.oshai.kotlinlogging.KotlinLogging
 import io.ktor.client.*
+import io.ktor.client.call.*
 import io.ktor.client.plugins.*
 import io.ktor.client.plugins.auth.*
 import io.ktor.client.plugins.auth.providers.*
 import io.ktor.client.plugins.contentnegotiation.*
+import io.ktor.client.request.*
 import io.ktor.serialization.kotlinx.json.*
+import io.ktor.util.network.*
+import kotlinx.io.IOException
 import kotlinx.serialization.ExperimentalSerializationApi
+import kotlinx.serialization.SerializationException
 import kotlinx.serialization.json.Json
 import net.keinekekse.app.auth.Authenticator
 import org.koin.core.annotation.Single
@@ -18,6 +23,7 @@ private val logger = KotlinLogging.logger {}
 @Single
 fun createHttpClient(authenticator: Authenticator): HttpClient {
     val client = HttpClient {
+        expectSuccess = true
         install(Auth) {
             bearer {
                 loadTokens {
@@ -36,7 +42,6 @@ fun createHttpClient(authenticator: Authenticator): HttpClient {
                 }
             }
         }
-
         install(ContentNegotiation) {
             json(Json {
                 prettyPrint = true
@@ -50,6 +55,7 @@ fun createHttpClient(authenticator: Authenticator): HttpClient {
             requestTimeoutMillis = 10000
             connectTimeoutMillis = 5000
         }
+
     }
 
     client.plugin(HttpSend).intercept { request ->
@@ -67,3 +73,54 @@ fun createHttpClient(authenticator: Authenticator): HttpClient {
 
     return client
 }
+
+// HTTP-Error-Handling -> https://stackoverflow.com/questions/54679592/handling-exception-in-httpclient-ktor
+
+sealed class ApiResponse<out T, out E> {
+    /**
+     * Represents successful network responses (2xx).
+     */
+    data class Success<T>(val body: T) : ApiResponse<T, Nothing>()
+
+    sealed class ErrorResponse<E> : ApiResponse<Nothing, E>() {
+        /**
+         * Represents server (50x) and client (40x) errors.
+         */
+        data class HttpError<E>(val code: Int, val errorBody: E?) : ErrorResponse<E>()
+
+        /**
+         * Represent IOExceptions and connectivity issues.
+         */
+        data class NetworkError(val exception: String) : ErrorResponse<Nothing>()
+
+        /**
+         * Represent SerializationExceptions.
+         */
+        object SerializationError : ErrorResponse<Nothing>()
+    }
+}
+
+suspend inline fun <reified T, reified E> HttpClient.safeRequest(
+    block: HttpRequestBuilder.() -> Unit,
+): ApiResponse<T, E> =
+    try {
+        val response = request { block() }
+        ApiResponse.Success(response.body())
+    } catch (e: ClientRequestException) {
+        ApiResponse.ErrorResponse.HttpError(e.response.status.value, e.errorBody())
+    } catch (e: ServerResponseException) {
+        ApiResponse.ErrorResponse.HttpError(e.response.status.value, e.errorBody())
+    } catch (e: IOException) {
+        ApiResponse.ErrorResponse.NetworkError(e.toString())
+    } catch (e: UnresolvedAddressException) { // no Network
+        ApiResponse.ErrorResponse.NetworkError(e.toString())
+    } catch (_: SerializationException) {
+        ApiResponse.ErrorResponse.SerializationError
+    }
+
+suspend inline fun <reified E> ResponseException.errorBody(): E? =
+    try {
+        response.body()
+    } catch (_: SerializationException) {
+        null
+    }