AMBARI-7676. Stack API generates invalid json files at "content" area (dlysnichenko)

ambari-server/src/main/java/org/apache/ambari/server/api/services/serializers/JsonSerializer.java

@@ -115,7 +115,10 @@ public class JsonSerializer implements ResultSerializer {
     }
 
     if (isArray(node)) {
-      m_generator.writeArrayFieldStart(node.getName());
+      if (node.getName() != null)
+        m_generator.writeArrayFieldStart(node.getName());
+      else
+        m_generator.writeStartArray();
     }
 
     for (TreeNode<Resource> child : node.getChildren()) {
@@ -139,7 +142,9 @@ public class JsonSerializer implements ResultSerializer {
 
   // Determines whether or not the given node is an array
   private boolean isArray(TreeNode<Resource> node) {
-    return node.getObject() == null && node.getName() != null;
+    return (node.getObject() == null && node.getName() != null) ||
+            (node.getObject() == null && node.getName() == null &&
+             node.getChildren().size() > 1);
   }
 
   private TreeNode<Map<String, Object>> getTreeProperties (Map<String, Map<String, Object>> propertiesMap) {

ambari-server/src/test/java/org/apache/ambari/server/api/services/serializers/JsonSerializerTest.java

@@ -101,7 +101,7 @@ public class JsonSerializerTest {
 
 
     TreeNode<Resource> resourcesNode = tree.addChild(null, "resources");
-
+    
 
     resourcesNode.addChild(resource, "resource1");
 
@@ -145,4 +145,68 @@ public class JsonSerializerTest {
 
     verify(uriInfo, resource);
   }
+  
+  @Test
+  public void testSerializeResourcesAsArray() throws Exception {
+    UriInfo uriInfo = createMock(UriInfo.class);
+    Resource resource = createMock(Resource.class);
+    //Resource resource2 = createMock(Resource.class);
+
+    Result result = new ResultImpl(true);
+    result.setResultStatus(new ResultStatus(ResultStatus.STATUS.OK));
+    TreeNode<Resource> tree = result.getResultTree();
+    //tree.setName("items");
+    TreeNode<Resource> child = tree.addChild(resource, "resource1");
+    child.setProperty("href", "this is an href");
+    tree.addChild(resource, "resource2");
+    //child.addChild(resource2, "sub-resource");
+
+    // resource properties
+    HashMap<String, Object> mapRootProps = new HashMap<String, Object>();
+    mapRootProps.put("prop1", "value1");
+    mapRootProps.put("prop2", "value2");
+
+    HashMap<String, Object> mapCategoryProps = new HashMap<String, Object>();
+    mapCategoryProps.put("catProp1", "catValue1");
+    mapCategoryProps.put("catProp2", "catValue2");
+
+    Map<String, Map<String, Object>> propertyMap = new HashMap<String, Map<String, Object>>();
+
+    propertyMap.put(null, mapRootProps);
+    propertyMap.put("category", mapCategoryProps);
+
+    //expectations
+    expect(resource.getPropertiesMap()).andReturn(propertyMap).anyTimes();
+    expect(resource.getType()).andReturn(Resource.Type.Cluster).anyTimes();
+
+    replay(uriInfo, resource/*, resource2*/);
+
+    //execute test
+    Object o = new JsonSerializer().serialize(result);
+    String expected = "[\n" +
+    "  {\n" +
+    "    \"href\" : \"this is an href\",\n" +
+    "    \"prop2\" : \"value2\",\n" +
+    "    \"prop1\" : \"value1\",\n" +
+    "    \"category\" : {\n" +
+    "      \"catProp1\" : \"catValue1\",\n" +
+    "      \"catProp2\" : \"catValue2\"\n" +
+    "    }\n" +
+    "  },\n" +
+    "  {\n" +
+    "    \"prop2\" : \"value2\",\n" +
+    "    \"prop1\" : \"value1\",\n" +
+    "    \"category\" : {\n" +
+    "      \"catProp1\" : \"catValue1\",\n" +
+    "      \"catProp2\" : \"catValue2\"\n" +
+    "    }\n" +
+    "  }\n" +
+    "]";
+
+    assertEquals(expected, o);
+
+    verify(uriInfo, resource/*, resource2*/);
+  }
+    
+  
 }