Initialize SftpClient only once at service startup

src/main/kotlin/Ingester.kt

@@ -28,11 +28,10 @@ import org.fcrepo.client.FcrepoOperationFailedException
 import org.memobase.fedora.FedoraClient
 import org.memobase.fedora.FedoraTransactionClient
 import org.memobase.fedora.RdfContentTypes
-import org.memobase.settings.SftpSettings
 import org.memobase.sftp.SftpClient
 
 class Ingester(
-    private val sftpSettings: SftpSettings,
+    private val sftpClient: SftpClient,
     private val fedoraClient: FedoraClient,
     private val externalBaseUrl: String
 ) {
@@ -83,18 +82,15 @@ class Ingester(
     }
 
     private fun ingestBinaries(sftpLocators: List<Pair<String, String?>>, rdfHandler: RdfHandler, transaction: FedoraTransactionClient) {
-        SftpClient(sftpSettings).use { sftpClient ->
-            log.info("Connected to sFTP server.")
-            sftpLocators.forEach {
-                val digitalInstantiationUrl = it.first
-                it.second.let { path ->
-                    if (path != null) {
-                        sftpClient.open(File(path)).use { stream ->
-                            val binaryUri = "$digitalInstantiationUrl/${Service.BINARY_FILE_URI_PATH}"
-                            val mimeType = rdfHandler.getMimeType(digitalInstantiationUrl)
-                            log.info("Ingesting binary $binaryUri with mime type $mimeType.")
-                            transaction.createOrUpdateBinaryResource(URI(binaryUri), stream, mimeType)
-                        }
+        sftpLocators.forEach {
+            val digitalInstantiationUrl = it.first
+            it.second.let { path ->
+                if (path != null) {
+                    sftpClient.open(File(path)).use { stream ->
+                        val binaryUri = "$digitalInstantiationUrl/${Service.BINARY_FILE_URI_PATH}"
+                        val mimeType = rdfHandler.getMimeType(digitalInstantiationUrl)
+                        log.info("Ingesting binary $binaryUri with mime type $mimeType.")
+                        transaction.createOrUpdateBinaryResource(URI(binaryUri), stream, mimeType)
                     }
                 }
             }

src/main/kotlin/Service.kt

@@ -18,6 +18,8 @@
 
 package org.memobase
 
+import java.io.Closeable
+import java.util.Properties
 import org.apache.kafka.clients.consumer.ConsumerRecord
 import org.apache.logging.log4j.LogManager
 import org.apache.logging.log4j.Logger
@@ -27,8 +29,7 @@ import org.memobase.exceptions.SftpClientException
 import org.memobase.fedora.FedoraClient
 import org.memobase.fedora.FedoraClientImpl
 import org.memobase.settings.SettingsLoader
-import java.io.Closeable
-import java.util.*
+import org.memobase.sftp.SftpClient
 
 class Service(fileName: String = "app.yml") : Closeable {
 
@@ -68,6 +69,7 @@ class Service(fileName: String = "app.yml") : Closeable {
     private val isSimple = (settings.appSettings.getProperty("isSimple") ?: "false").toBoolean()
     private var consumer: Consumer
     private var producer: Producer
+    private var sftpClient: SftpClient? = null
 
     init {
         val consumerSettings = settings.kafkaConsumerSettings
@@ -75,7 +77,11 @@ class Service(fileName: String = "app.yml") : Closeable {
         consumerSettings.setProperty("max.poll.interval.ms", CONSUMER_MAX_INTERVAL_MS)
         consumer = Consumer(consumerSettings, settings.inputTopic)
         producer = Producer(settings.kafkaProducerSettings, settings.processReportTopic)
-        log.info("Connected to Kafka.")
+        log.info("Connected to Kafka cluster.")
+        if (!isSimple) {
+            sftpClient = SftpClient(settings.sftpSettings)
+            log.info("Connected to sFTP server.")
+        }
     }
 
     fun run() {
@@ -84,7 +90,7 @@ class Service(fileName: String = "app.yml") : Closeable {
         }
     }
 
-    private fun processRecords() {
+    fun processRecords() {
         for (record in consumer.fetchRecords()) {
             val ingestReport = if (isSimple)
                 processSingleEntity(record)
@@ -121,14 +127,16 @@ class Service(fileName: String = "app.yml") : Closeable {
     }
 
     private fun processRecord(record: ConsumerRecord<String, String>): Report {
-        val ingester = Ingester(
-            settings.sftpSettings,
-            fedoraClient,
-            settings.appSettings.getProperty("$FEDORA_PROPERTIES_PREFIX.externalBaseUrl")
-        )
+        val ingester = sftpClient?.let {
+            Ingester(
+                it,
+                fedoraClient,
+                settings.appSettings.getProperty("$FEDORA_PROPERTIES_PREFIX.externalBaseUrl")
+            )
+        }
 
         return try {
-            ingester.ingest(record.key(), record.value())
+            ingester?.ingest(record.key(), record.value())
             Report(
                 id = record.key(),
                 status = ReportStatus.success,
@@ -168,5 +176,6 @@ class Service(fileName: String = "app.yml") : Closeable {
     override fun close() {
         consumer.close()
         producer.close()
+        sftpClient?.close()
     }
 }