DATAREST-956 handle add and remove item to nested collections

Author: Mathias Düsterhöft

spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/json/DomainObjectReader.java

@@ -48,6 +48,7 @@
  * @author Oliver Gierke
  * @author Mark Paluch
  * @author Craig Andrews
+ * @author Mathias Düsterhöft
  * @since 2.2
  */
 @RequiredArgsConstructor
@@ -175,7 +176,7 @@ private <T> T doMerge(ObjectNode root, T target, ObjectMapper mapper) throws Exc
 
 if (child.isArray()) {
 
-boolean nestedObjectFound = handleArrayNode((ArrayNode) child, asCollection(rawValue), mapper);
+boolean nestedObjectFound = handleArrayNode((ArrayNode) child, asCollection(rawValue), property.getComponentType(), mapper);
 
 if (nestedObjectFound) {
 i.remove();
@@ -224,10 +225,10 @@ private <T> T doMerge(ObjectNode root, T target, ObjectMapper mapper) throws Exc
  * 
  * @param array the source {@link ArrayNode}m, must not be {@literal null}.
  * @param collection the actual collection values, must not be {@literal null}.
- * @param mapper the {@link ObjectMapper} to use, must not be {@literal null}.
- * @return whether an object merge has been applied to the {@link ArrayNode}.
+ * @param componentType the item type of the collection
+ * @param mapper the {@link ObjectMapper} to use, must not be {@literal null}. @return whether an object merge has been applied to the {@link ArrayNode}.
  */
-private boolean handleArrayNode(ArrayNode array, Collection<Object> collection, ObjectMapper mapper)
+private boolean handleArrayNode(ArrayNode array, Collection<Object> collection, Class<?> componentType, ObjectMapper mapper)
 throws Exception {
 
 Assert.notNull(array, "ArrayNode must not be null!");
@@ -240,13 +241,18 @@ private boolean handleArrayNode(ArrayNode array, Collection<Object> collection,
 for (JsonNode jsonNode : array) {
 
 if (!value.hasNext()) {
+if (componentType != null) {
+collection.add(mapper.treeToValue(jsonNode, componentType));
+}
 return nestedObjectFound;
 }
 
 Object next = value.next();
 
 if (ArrayNode.class.isInstance(jsonNode)) {
-return handleArrayNode(array, asCollection(next), mapper);
+final Collection<Object> nestedCollection = asCollection(next);
+final Iterator<Object> iterator = nestedCollection.iterator();
+return handleArrayNode(array, nestedCollection, iterator.hasNext() ? iterator.next().getClass() : null, mapper);
 }
 
 if (ObjectNode.class.isInstance(jsonNode)) {
@@ -256,6 +262,12 @@ private boolean handleArrayNode(ArrayNode array, Collection<Object> collection,
 }
 }
 
+while (value.hasNext()) {
+//there are more items in the collection than contained in the json node - remove it.
+value.next();
+value.remove();
+}
+
 return nestedObjectFound;
 }
 
@@ -284,7 +296,9 @@ private void doMergeNestedMap(Map<String, Object> source, ObjectNode node, Objec
 if (child instanceof ObjectNode && sourceValue != null) {
 doMerge((ObjectNode) child, sourceValue, mapper);
 } else if (child instanceof ArrayNode && sourceValue != null) {
-handleArrayNode((ArrayNode) child, asCollection(sourceValue), mapper);
+final Collection<Object> nestedCollection = asCollection(sourceValue);
+final Iterator<Object> iterator = nestedCollection.iterator();
+handleArrayNode((ArrayNode) child, nestedCollection, iterator.hasNext() ? iterator.next().getClass() : null, mapper);
 } else {
 source.put(entry.getKey(),
 mapper.treeToValue(child, sourceValue == null ? Object.class : sourceValue.getClass()));

spring-data-rest-webmvc/src/test/java/org/springframework/data/rest/webmvc/json/DomainObjectReaderUnitTests.java

@@ -19,6 +19,9 @@
 import static org.junit.Assert.*;
 import static org.mockito.Mockito.*;
 
+import lombok.AllArgsConstructor;
+import lombok.NoArgsConstructor;
+
 import java.io.ByteArrayInputStream;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -60,6 +63,7 @@
  * 
  * @author Oliver Gierke
  * @author Craig Andrews
+ * @author Mathias Düsterhöft
  */
 @RunWith(MockitoJUnitRunner.class)
 public class DomainObjectReaderUnitTests {
@@ -373,6 +377,51 @@ public void writesArrayForPut() throws Exception {
 assertThat(result.inner.items.get(0).some, is("value"));
 }
 
+/**
+ * @see DATAREST-956
+ */
+@Test
+public void writesArrayWithAddedItemForPut() throws Exception {
+
+Child inner = new Child();
+inner.items = new ArrayList<Item>();
+inner.items.add(new Item());
+
+Parent source = new Parent();
+source.inner = inner;
+
+JsonNode node = new ObjectMapper().readTree("{ \"inner\" : { \"items\" : [ { \"some\" : \"value\" }, { \"some\" : \"value1\" } ] } }");
+
+Parent result = reader.readPut((ObjectNode) node, source, new ObjectMapper());
+
+assertThat(result.inner.items.size(), is(2));
+assertThat(result.inner.items.get(0).some, is("value"));
+assertThat(result.inner.items.get(1).some, is("value1"));
+}
+
+/**
+ * @see DATAREST-956
+ */
+@Test
+public void writesArrayWithRemovedItemForPut() throws Exception {
+
+Child inner = new Child();
+inner.items = new ArrayList<Item>();
+inner.items.add(new Item("test1"));
+inner.items.add(new Item("test2"));
+inner.items.add(new Item("test3"));
+
+Parent source = new Parent();
+source.inner = inner;
+
+JsonNode node = new ObjectMapper().readTree("{ \"inner\" : { \"items\" : [ { \"some\" : \"value\" } ] } }");
+
+Parent result = reader.readPut((ObjectNode) node, source, new ObjectMapper());
+
+assertThat(result.inner.items.size(), is(1));
+assertThat(result.inner.items.get(0).some, is("value"));
+}
+
 @JsonAutoDetect(fieldVisibility = Visibility.ANY)
 static class TypeWithGenericMap {
 
@@ -440,6 +489,8 @@ static class Child {
 }
 
 @JsonAutoDetect(fieldVisibility = Visibility.ANY)
+@NoArgsConstructor
+@AllArgsConstructor
 static class Item {
 String some;
 }