WorkflowResponse json issues

This commit adds some robustness to the interface between the
API-H and BPMN, specifically, in how the response is handled.

I don't have proof, but there appears to be some randomness to
the json provider behavior when used with the jax-rs. Sometimes,
the serializer is adding the root element, and sometimes it
is not.  Maybe there's something wrong with the configuration.
Maybe we have competing json providers.  I couldn't pin this
down.

I'm almost certain it is the presence of the root element in
the content that causes the API-H code to fail parsing of the
BPMN response.  This doesn't kill the request, as you might
expect, but rather, the API-H passes the BPMN response through
to the client (VID, or policy, or whatever).

The original problem (SO-586) was "fixed" by "removing the
wrapper".  This "wrapper" is a needed feature of the interface
between BPMN and the API-H.  We shouldn't have removed it.
The fact that the "fix" appeared to work is due to the
behavior I described in the previous paragraph.  The API-H
chokes on the message, and it passes it through unchanged.
Not really what we want.

So, I don't know why the jackson/json behavior is flaky and
different now, but I can (and did) modify the API-H so it can
parse a json message whether or not it has a root element.

Note that WorkflowResponse.java (in BPMN) and CamundaResponse.java
(in the API-H) are basically the same bean representing the
message format.  Seems less than ideal to have two different
classes.

Also note that I changed the name of the "response" attribute
of the WorkflowResponse and CamundaResponse classes to "content".
Got tired of seeing this nonsense everywhere in the code:
	response.getResponse()

Change-Id: Icaf70f8457de99e493cf882170fe778c620308c9
Issue-ID: SO-586
Issue-ID: SO-618
Signed-off-by: Rob Daugherty <rd472p@att.com>

2 files changed, 106 insertions, 0 deletions

diff --git a/common/src/main/java/org/openecomp/mso/utils/RootIgnoringJsonDeserializer.java b/common/src/main/java/org/openecomp/mso/utils/RootIgnoringJsonDeserializer.java
new file mode 100644
index 0000000000..95f72c4dd4
--- /dev/null
+++ b/common/src/main/java/org/openecomp/mso/utils/RootIgnoringJsonDeserializer.java
@@ -0,0 +1,67 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * ONAP - SO
+ * ================================================================================
+ * Copyright (C) 2017 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.openecomp.mso.utils;
+
+import java.io.IOException;
+import java.util.Map;
+
+import com.fasterxml.jackson.annotation.JsonRootName;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonDeserializer;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+/**
+ * A JSON deserializer that ignores the root element if it is present.
+ */
+public class RootIgnoringJsonDeserializer<T> extends JsonDeserializer<T> {
+
+	private final ObjectMapper mapper = new ObjectMapper();
+	private final Class<T> clazz;
+	private final String jsonRootName;
+
+	public RootIgnoringJsonDeserializer(Class<T> clazz) {
+		this.clazz = clazz;
+
+		JsonRootName annotation = clazz.getAnnotation(JsonRootName.class);
+		
+		if (annotation == null || annotation.value() == null || annotation.value().equals("")) {
+			jsonRootName = clazz.getSimpleName();
+		} else {
+			jsonRootName = annotation.value();
+		}
+	}
+
+	@Override
+	public T deserialize(JsonParser jp, DeserializationContext dc) 
+			throws IOException, JsonProcessingException {
+	   JsonNode rootNode = jp.getCodec().readTree(jp);
+	   Map.Entry<String,JsonNode> field = rootNode.fields().next();
+
+	   if (jsonRootName.equals(field.getKey())) {
+		   rootNode = field.getValue();
+	   }
+
+	   return mapper.convertValue(rootNode, clazz);
+	}
+}
\ No newline at end of file
diff --git a/common/src/main/java/org/openecomp/mso/utils/RootIgnoringObjectMapper.java b/common/src/main/java/org/openecomp/mso/utils/RootIgnoringObjectMapper.java
new file mode 100644
index 0000000000..6f3c5b7d99
--- /dev/null
+++ b/common/src/main/java/org/openecomp/mso/utils/RootIgnoringObjectMapper.java
@@ -0,0 +1,39 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * ONAP - SO
+ * ================================================================================
+ * Copyright (C) 2017 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.openecomp.mso.utils;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.module.SimpleModule;
+
+/**
+ * An ObjectMapper for a specific class that ignores the root element
+ * if it is present.
+ */
+public class RootIgnoringObjectMapper<T> extends ObjectMapper {
+
+	private static final long serialVersionUID = 6812584067195377395L;
+
+	public RootIgnoringObjectMapper(Class<T> clazz) {
+		SimpleModule module = new SimpleModule();
+		module.addDeserializer(clazz, new RootIgnoringJsonDeserializer<T>(clazz));
+		registerModule(module);
+	}
+}
\ No newline at end of file