DATACOUCH-36 - Don't allow NULL values to be stored.

It is illegal to store a NULL value as a document. An attempt to do so will
throw an IllegalArgumentException.

-=david=-

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

@@ -104,7 +104,7 @@ public class CouchbaseDocument implements CouchbaseStorable {
    * @return the {@link CouchbaseDocument} for chaining.
    */
   public final CouchbaseDocument put(final String key, final Object value) {
-    verifyValueType(value.getClass());
+    verifyValueType(value);
 
     payload.put(key, value);
     return this;
@@ -259,15 +259,19 @@ public class CouchbaseDocument implements CouchbaseStorable {
    * <p>If this is not the case, a {@link IllegalArgumentException} is
    * thrown.</p>
    *
-   * @param clazz the class type to check and verify.
+   * Objects that are NULL cannot be stored.
+   *
+   * @param value the object to verify its type.
    */
-  private void verifyValueType(final Class<?> clazz) {
-    if (simpleTypeHolder.isSimpleType(clazz)) {
-      return;
+  private void verifyValueType(final Object value) {
+    if(value == null) {
+      throw new IllegalArgumentException("Attribute of type null cannot be stored.");
     }
-
-    throw new IllegalArgumentException("Attribute of type "
-      + clazz.getCanonicalName() + " can not be stored and must be converted.");
+    final Class<?> clazz = value.getClass();
+    if (simpleTypeHolder.isSimpleType(clazz)) {
+        return;
+    }
+    throw new IllegalArgumentException("Attribute of type " + clazz.getCanonicalName() + " cannot be stored and must be converted.");
   }
 
   /**

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

@@ -179,6 +179,18 @@ public class CouchbaseTemplateTests {
       assertNotNull(beer.getActive());
     }
   }
+
+  @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);
+    }
+  }
   
   /**
    * A sample document with just an id and property.