DATACOUCH-58 allow for null values to be persisted for List elements and Map values.

src/main/java/org/springframework/data/couchbase/core/convert/translation/JacksonTranslationService.java

@@ -227,6 +227,8 @@ public class JacksonTranslationService implements TranslationService, Initializi
         }
       case VALUE_NUMBER_FLOAT:
         return parser.getValueAsDouble();
+      case VALUE_NULL:
+        return null;
       default:
         throw new MappingException("Could not decode primitve value " + token);
     }

src/main/java/org/springframework/data/couchbase/core/mapping/CouchbaseDocument.java

@@ -259,13 +259,11 @@ public class CouchbaseDocument implements CouchbaseStorable {
    * <p>If this is not the case, a {@link IllegalArgumentException} is
    * thrown.</p>
    *
-   * Objects that are NULL cannot be stored.
-   *
    * @param value the object to verify its type.
    */
   private void verifyValueType(final Object value) {
     if(value == null) {
-      throw new IllegalArgumentException("Attribute of type null cannot be stored.");
+      return;
     }
     final Class<?> clazz = value.getClass();
     if (simpleTypeHolder.isSimpleType(clazz)) {

src/main/java/org/springframework/data/couchbase/core/mapping/CouchbaseList.java

@@ -69,7 +69,7 @@ public class CouchbaseList implements CouchbaseStorable {
    * @return the {@link CouchbaseList} object for chaining purposes.
    */
   public final CouchbaseList put(final Object value) {
-    verifyValueType(value.getClass());
+    verifyValueType(value);
 
     payload.add(value);
     return this;
@@ -170,9 +170,14 @@ public class CouchbaseList implements CouchbaseStorable {
    * <p>If this is not the case, a {@link IllegalArgumentException} is
    * thrown.</p>
    *
-   * @param clazz the class type to check and verify.
+   * @param value the object to verify its type.
    */
-  private void verifyValueType(final Class<?> clazz) {
+  private void verifyValueType(final Object value) {
+    if(value == null) {
+      return;
+    }
+
+    final Class<?> clazz = value.getClass();
     if (simpleTypeHolder.isSimpleType(clazz)) {
       return;
     }

src/test/java/org/springframework/data/couchbase/core/CouchbaseTemplateTests.java

@@ -43,7 +43,6 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
-import static org.junit.Assert.fail;
 
 /**
  * @author Michael Nitschinger
@@ -133,10 +132,12 @@ public class CouchbaseTemplateTests {
     List<String> names = new ArrayList<String>();
     names.add("Michael");
     names.add("Thomas");
+    names.add(null);
     List<Integer> votes = new LinkedList<Integer>();
     Map<String, Boolean> info1 = new HashMap<String, Boolean>();
     info1.put("foo", true);
     info1.put("bar", false);
+    info1.put("nullValue", null);
     Map<String, Integer> info2 = new HashMap<String, Integer>();
 
     ComplexPerson complex = new ComplexPerson(id, names, votes, info1, info2);
@@ -144,8 +145,8 @@ public class CouchbaseTemplateTests {
     template.save(complex);
 
     String expected = "{\"_class\":\"org.springframework.data.couchbase.core."
-            + "CouchbaseTemplateTests$ComplexPerson\",\"info1\":{\"foo\":true,\"bar\""
-            + ":false},\"votes\":[],\"firstnames\":[\"Michael\",\"Thomas\"],\"info2\":"
+            + "CouchbaseTemplateTests$ComplexPerson\",\"info1\":{\"nullValue\":null,\"foo\":true,\"bar\""
+            + ":false},\"votes\":[],\"firstnames\":[\"Michael\",\"Thomas\",null],\"info2\":"
             + "{}}";
     assertEquals(expected, client.get(id));
 
@@ -189,18 +190,6 @@ public class CouchbaseTemplateTests {
     }
   }
 
-  @Test
-  public void shouldNotSaveNull() {
-    final Map<String, String> things = new HashMap<String, String>();
-    things.put("key", null);
-    try {
-      template.save(things);
-      fail("We should not be able to store a NULL!");
-    } catch (final IllegalArgumentException e) {
-      assertTrue(true);
-    }
-  }
-
   @Test
   public void shouldDeserialiseLongs() {
     final long time = new Date().getTime();