DATAREDIS-1175 - Allow direct mapping of Collection like structures like java.util.List via MappingRedisConverter.

It is now possible to hand a plain list to the converter that is then converted into a hash structure using index numbers as keys. Original pull request: spring-projects#546.

Author: christophstrobl

src/main/java/org/springframework/data/redis/core/convert/MappingRedisConverter.java

@@ -176,6 +176,11 @@ public MappingRedisConverter(@Nullable RedisMappingContext mappingContext, @Null
  */
 @Override
 public <R> R read(Class<R> type, RedisData source) {
+
+TypeInformation<?> readType = typeMapper.readType(source.getBucket().getPath(), ClassTypeInformation.from(type));
+if(readType.isCollectionLike()) {
+return (R) readCollectionOrArray("", ArrayList.class, Object.class, source.getBucket());
+}
 return readInternal("", type, source);
 }
 
@@ -395,7 +400,11 @@ public void write(Object source, RedisData sink) {
 
 sink.setKeyspace(entity.getKeySpace());
 
-writeInternal(entity.getKeySpace(), "", source, entity.getTypeInformation(), sink);
+if(entity.getTypeInformation().isCollectionLike()) {
+writeCollection(entity.getKeySpace(), "", (List) source, entity.getTypeInformation().getComponentType(), sink);
+} else {
+writeInternal(entity.getKeySpace(), "", source, entity.getTypeInformation(), sink);
+}
 
 Object identifier = entity.getIdentifierAccessor(source).getIdentifier();
 
@@ -713,7 +722,7 @@ private void writeCollection(String keyspace, String path, @Nullable Iterable<?>
 break;
 }
 
-String currentPath = path + ".[" + i + "]";
+String currentPath = path + (path.equals("") ? "" : ".") + "[" + i + "]";
 
 if (!ClassUtils.isAssignable(typeHint.getType(), value.getClass())) {
 throw new MappingException(

src/test/java/org/springframework/data/redis/core/convert/MappingRedisConverterUnitTests.java

@@ -36,6 +36,7 @@
 import java.util.Date;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.UUID;
 
@@ -1884,6 +1885,38 @@ public void readEntityWithCustomConverter() {
 assertThat(target.getAccountName()).isEqualTo("Golam Mazid Sajib");
 }
 
+@Test // DATAREDIS-1175
+public void writePlainList() {
+
+List<Object> source = Arrays.asList("Hello", "stream", "message", 100L);
+RedisTestData target = write(source);
+
+System.out.println(target.getBucket().toString());
+
+assertThat(target).containsEntry("[0]", "Hello") //
+.containsEntry("[1]", "stream") //
+.containsEntry("[2]", "message") //
+.containsEntry("[3]", "100");
+}
+
+@Test // DATAREDIS-1175
+public void readPlainList() {
+
+Map<String, String> source = new LinkedHashMap<>();
+source.put("[0]._class", "java.lang.String");
+source.put("[0]", "Hello");
+source.put("[1]._class", "java.lang.String");
+source.put("[1]", "stream");
+source.put("[2]._class", "java.lang.String");
+source.put("[2]", "message");
+source.put("[3]._class", "java.lang.Long");
+source.put("[3]", "100");
+
+List target = read(List.class, source);
+
+assertThat(target).containsExactly("Hello", "stream", "message", 100L);
+}
+
 private RedisTestData write(Object source) {
 
 RedisData rdo = new RedisData();

src/test/java/org/springframework/data/redis/test/util/RedisTestData.java

@@ -140,13 +140,20 @@ private String getString(String path) {
 return actual.get(path);
 }
 
-private static Map<String, String> toStringMap(Map<String, byte[]> source) {
+}
 
-Map<String, String> converted = new LinkedHashMap<>();
 
-source.forEach((k, v) -> converted.put(k, new String(v, StandardCharsets.UTF_8)));
+private static Map<String, String> toStringMap(Map<String, byte[]> source) {
 
-return converted;
-}
+Map<String, String> converted = new LinkedHashMap<>();
+
+source.forEach((k, v) -> converted.put(k, new String(v, StandardCharsets.UTF_8)));
+
+return converted;
+}
+
+@Override
+public String toString() {
+return toStringMap(getBucket().asMap()).toString();
 }
 }