Add serializeIterable API to SerializerAdapter (Azure#19459)

* Add serializeIterable API to SerializerAdapter

* Fix checkstyle

Author: srnagar

sdk/core/azure-core/src/main/java/com/azure/core/util/serializer/JacksonAdapter.java

@@ -188,15 +188,7 @@ public String serializeRaw(Object object) {
 
     @Override
     public String serializeList(List<?> list, CollectionFormat format) {
-        if (list == null) {
-            return null;
-        }
-        List<String> serialized = new ArrayList<>();
-        for (Object element : list) {
-            String raw = serializeRaw(element);
-            serialized.add(raw != null ? raw : "");
-        }
-        return String.join(format.getDelimiter(), serialized);
+        return serializeIterable(list, format);
     }
 
     @Override

sdk/core/azure-core/src/main/java/com/azure/core/util/serializer/SerializerAdapter.java

@@ -12,6 +12,8 @@
 import java.lang.reflect.Type;
 import java.nio.charset.StandardCharsets;
 import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.StreamSupport;
 
 /**
  * An interface defining the behaviors of a serializer.
@@ -63,6 +65,24 @@ default void serialize(final Object object, final SerializerEncoding encoding, O
      */
     String serializeList(List<?> list, CollectionFormat format);
 
+    /**
+     * Serializes an iterable into a string with the delimiter specified with the Swagger collection format joining each
+     * individual serialized items in the list.
+     *
+     * @param iterable the iterable to serialize
+     * @param format the Swagger collection format
+     * @return the serialized string
+     */
+    default String serializeIterable(Iterable<?> iterable, CollectionFormat format) {
+        if (iterable == null) {
+            return null;
+        }
+        return StreamSupport.stream(iterable.spliterator(), false)
+            .map(this::serializeRaw)
+            .map(serializedString -> serializedString == null ? "" : serializedString)
+            .collect(Collectors.joining(format.getDelimiter()));
+    }
+
     /**
      * Deserializes a string into a {@code T} object.
      *

sdk/core/azure-core/src/test/java/com/azure/core/util/serializer/JacksonAdapterTests.java

@@ -14,7 +14,9 @@
 import java.io.IOException;
 import java.time.OffsetDateTime;
 import java.time.ZoneOffset;
+import java.util.Arrays;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.stream.Stream;
 
@@ -64,26 +66,42 @@ public void mapWithEmptyKeyAndNonEmptyValue() throws IOException {
     }
 
     private static class MapHolder {
+
         @JsonInclude(content = JsonInclude.Include.ALWAYS)
         private Map<String, String> map = new HashMap<>();
-
         public Map<String, String> map() {
             return map;
         }
 
         public void map(Map<String, String> map) {
             this.map = map;
         }
-    }
 
+    }
     @JacksonXmlRootElement(localName = "XmlString")
     private static class XmlString {
+
         @JsonProperty("Value")
         private String value;
-
         public String getValue() {
             return value;
         }
+
+    }
+    @ParameterizedTest
+    @MethodSource("serializeCollectionSupplier")
+    public void testSerializeList(List<?> values, CollectionFormat format, String expectedSerializedString) {
+        String actualSerializedString = JacksonAdapter.createDefaultSerializerAdapter()
+            .serializeList(values, format);
+        assertEquals(expectedSerializedString, actualSerializedString);
+    }
+
+    @ParameterizedTest
+    @MethodSource("serializeCollectionSupplier")
+    public void testSerializeIterable(Iterable<?> values, CollectionFormat format, String expectedSerializedString) {
+        String actualSerializedString = JacksonAdapter.createDefaultSerializerAdapter()
+            .serializeIterable(values, format);
+        assertEquals(expectedSerializedString, actualSerializedString);
     }
 
     @ParameterizedTest
@@ -95,6 +113,18 @@ public void deserializeJson(String json, OffsetDateTime expected) throws IOExcep
         assertEquals(expected, wrapper.getOffsetDateTime());
     }
 
+    private static Stream<Arguments> serializeCollectionSupplier() {
+        return Stream.of(
+            Arguments.of(Arrays.asList("foo", "bar", "baz"), CollectionFormat.CSV, "foo,bar,baz"),
+            Arguments.of(Arrays.asList("foo", null, "baz"), CollectionFormat.CSV, "foo,,baz"),
+            Arguments.of(Arrays.asList(null, "bar", null, null), CollectionFormat.CSV, ",bar,,"),
+            Arguments.of(Arrays.asList(1, 2, 3), CollectionFormat.CSV, "1,2,3"),
+            Arguments.of(Arrays.asList(1, 2, 3), CollectionFormat.PIPES, "1|2|3"),
+            Arguments.of(Arrays.asList(1, 2, 3), CollectionFormat.SSV, "1 2 3"),
+            Arguments.of(Arrays.asList("foo", "bar", "baz"), CollectionFormat.MULTI, "foo&bar&baz")
+        );
+    }
+
     private static Stream<Arguments> deserializeJsonSupplier() {
         final String jsonFormat = "{\"OffsetDateTime\":\"%s\"}";
         OffsetDateTime minValue = OffsetDateTime.of(1, 1, 1, 0, 0, 0, 0, ZoneOffset.UTC);