#24 Add once off Reader and Writer function

examples/src/main/scala/za/co/absa/kafkacase/examples/KafkaCase.scala

@@ -18,8 +18,8 @@ package za.co.absa.kafkacase.examples
 
 import org.apache.kafka.clients.consumer.ConsumerConfig
 import org.apache.kafka.clients.producer.ProducerConfig
-import za.co.absa.kafkacase.examples.reader.{ReaderCustomResourceHandling, ReaderManualResourceHandling, ReaderUsingsResourceHandling}
-import za.co.absa.kafkacase.examples.writer.{WriterCustomResourceHandling, WriterManualResourceHandling, WriterUsingsResourceHandling}
+import za.co.absa.kafkacase.examples.reader.{ReaderCustomResourceHandling, ReaderManualResourceHandling, ReaderReadOnce, ReaderUsingsResourceHandling}
+import za.co.absa.kafkacase.examples.writer.{WriterCustomResourceHandling, WriterManualResourceHandling, WriterUsingsResourceHandling, WriterWriteOnce}
 import za.co.absa.kafkacase.models.topics.EdlaChange
 
 import java.util.{Properties, UUID}
@@ -62,8 +62,10 @@ object KafkaCase {
     WriterManualResourceHandling(writerProps, topicName, sampleMessageToWrite)
     WriterCustomResourceHandling(writerProps, topicName, sampleMessageToWrite)
     WriterUsingsResourceHandling(writerProps, topicName, sampleMessageToWrite)
+    WriterWriteOnce(writerProps, topicName, sampleMessageToWrite)
     ReaderManualResourceHandling[EdlaChange](readerProps, topicName)
     ReaderCustomResourceHandling[EdlaChange](readerProps, topicName)
     ReaderUsingsResourceHandling[EdlaChange](readerProps, topicName)
+    ReaderReadOnce[EdlaChange](readerProps, topicName)
   }
 }

examples/src/main/scala/za/co/absa/kafkacase/examples/reader/ReaderReadOnce.scala

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2024 ABSA Group Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package za.co.absa.kafkacase.examples.reader
+
+import io.circe.Decoder
+import za.co.absa.kafkacase.reader.Reader
+
+import java.util.Properties
+
+object ReaderReadOnce {
+  def apply[T: Decoder](readerProps: Properties, topicName: String): Unit =
+    Reader.readOnce[T](readerProps, topicName, println)
+}

examples/src/main/scala/za/co/absa/kafkacase/examples/writer/WriterWriteOnce.scala

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2024 ABSA Group Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package za.co.absa.kafkacase.examples.writer
+
+import io.circe.Encoder
+import za.co.absa.kafkacase.writer.Writer
+
+import java.util.Properties
+
+object WriterWriteOnce {
+  def apply[T: Encoder](writerProps: Properties, topicName: String, sampleMessageToWrite: T): Unit =
+    Writer.writeOnce(writerProps, topicName, "sampleKey", sampleMessageToWrite)
+}

reader/src/main/scala/za/co/absa/kafkacase/reader/Reader.scala

@@ -16,4 +16,20 @@
 
 package za.co.absa.kafkacase.reader
 
+import io.circe.Decoder
+
+import java.util.Properties
+
 trait Reader[TType] extends Iterator[(String, Either[String, TType])] with AutoCloseable
+
+object Reader {
+  def readOnce[T: Decoder](readerProps: Properties, topicName: String, work: ((String, Either[String, T])) => Unit): Unit = {
+    val reader = new ReaderImpl[T](readerProps, topicName, neverEnding = false)
+    try {
+      for (item <- reader)
+        work(item)
+    } finally {
+      reader.close()
+    }
+  }
+}

writer/src/main/scala/za/co/absa/kafkacase/writer/Writer.scala

@@ -16,6 +16,10 @@
 
 package za.co.absa.kafkacase.writer
 
+import io.circe.Encoder
+
+import java.util.Properties
+
 trait Writer[TType] extends AutoCloseable {
   def write(key: String, value: TType): Unit
   def flush(): Unit
@@ -25,3 +29,14 @@ trait Writer[TType] extends AutoCloseable {
     flush()
   }
 }
+
+object Writer {
+  def writeOnce[T: Encoder](writerProps: Properties, topicName: String, messageKey: String, sampleMessageToWrite: T): Unit = {
+    val writer = new WriterImpl[T](writerProps, topicName)
+    try {
+      writer.write(messageKey, sampleMessageToWrite)
+    } finally {
+      writer.close()
+    }
+  }
+}