From 18f9cfa17d4fc7bcb30512db76f149fd8543acd6 Mon Sep 17 00:00:00 2001
From: Uttam Kumar <ukumar@linkedin.com>
Date: Wed, 21 Aug 2024 21:11:03 +0530
Subject: [PATCH] Serializable StringListView (#560)

* Serializable StringListView
---
 .../avroutil1/builder/SpecificRecordTest.java | 19 +++++++++++++++++++
 .../collectiontransformer/StringListView.java | 12 +++++++++++-
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/avro-builder/tests/tests-allavro/src/test/java/com/linkedin/avroutil1/builder/SpecificRecordTest.java b/avro-builder/tests/tests-allavro/src/test/java/com/linkedin/avroutil1/builder/SpecificRecordTest.java
index 9a53a58a..ebdcc492 100644
--- a/avro-builder/tests/tests-allavro/src/test/java/com/linkedin/avroutil1/builder/SpecificRecordTest.java
+++ b/avro-builder/tests/tests-allavro/src/test/java/com/linkedin/avroutil1/builder/SpecificRecordTest.java
@@ -11,10 +11,15 @@
 import com.linkedin.avroutil1.compatibility.RandomRecordGenerator;
 import com.linkedin.avroutil1.compatibility.RecordGenerationConfig;
 import com.linkedin.avroutil1.compatibility.StringConverterUtil;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.ObjectOutputStream;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.lang.reflect.Parameter;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -1946,6 +1951,20 @@ public void testCharSeqAccessorForNoUtf8() {
     Assert.assertEquals((int) instance.intAr.get(instance.getIntAr().size() - 1), Integer.MAX_VALUE);
   }
 
+  @Test
+  public void testIfSerializable() throws IOException {
+    Path tempFile = Files.createTempFile(null, ".tmp");
+    try (FileOutputStream fileOutputStream = new FileOutputStream(tempFile.toFile());
+        ObjectOutputStream objectOutputStream = new ObjectOutputStream(fileOutputStream)) {
+      vs19.TestCollections instance = new RandomRecordGenerator().randomSpecific(vs19.TestCollections.class,
+          RecordGenerationConfig.newConfig().withAvoidNulls(true));
+
+      objectOutputStream.writeObject(instance.getStrAr());
+    } finally {
+      Files.delete(tempFile);
+    }
+  }
+
   @BeforeClass
   public void setup() {
     System.setProperty("org.apache.avro.specific.use_custom_coders", "true");
diff --git a/helper/helper/src/main/java/com/linkedin/avroutil1/compatibility/collectiontransformer/StringListView.java b/helper/helper/src/main/java/com/linkedin/avroutil1/compatibility/collectiontransformer/StringListView.java
index 965db29c..0e44ccdd 100644
--- a/helper/helper/src/main/java/com/linkedin/avroutil1/compatibility/collectiontransformer/StringListView.java
+++ b/helper/helper/src/main/java/com/linkedin/avroutil1/compatibility/collectiontransformer/StringListView.java
@@ -5,15 +5,17 @@
  */
 package com.linkedin.avroutil1.compatibility.collectiontransformer;
 
+import java.io.Serializable;
 import java.util.AbstractList;
 import java.util.Iterator;
+import java.util.stream.Collectors;
 import org.apache.avro.util.Utf8;
 
 
 /**
  * View of Utf8 List to allow get as String while still allowing set to reflect on the original object.
  */
-public class StringListView extends AbstractList<String> {
+public class StringListView extends AbstractList<String> implements Serializable {
   // Not final to allow addition
   private java.util.List<Utf8> _utf8List;
 
@@ -102,4 +104,12 @@ public String next() {
       }
     };
   }
+
+  /**
+   * Custom serialization to write the list of strings instead of the list of Utf8.
+   * ObjectOutputStream seeks this method to serialize the object.
+   */
+  private void writeObject(java.io.ObjectOutputStream out) throws java.io.IOException {
+    out.writeObject(_utf8List.stream().map(Utf8::toString).collect(Collectors.toList()));
+  }
 }