Remove JAXB and XML, use GSON for JSON

This review converst apex-pdp to use GSON for JSON handling. In order to
preserve backward compatibility with the JAXB format of JSON, custom
handling of maps was required. Therefore, the policy-common
StandardCoder could not be used.

There are a lot of small changes, removing annotations from concepts and
tweaking of test data. However, this cleans up the code base so it is
worth doing.

Issue-ID: POLICY-1820
Change-Id: I213fa64f6d7f3f1df8d10f111d9fbedbe80f9fe0
Signed-off-by: liamfallon <liam.fallon@est.tech>

7 files changed, 14 insertions, 109 deletions

diff --git a/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/AxEvent.java b/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/AxEvent.java
index 8128b3d9a..a4c0e9db1 100644
--- a/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/AxEvent.java
+++ b/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/AxEvent.java
@@ -23,6 +23,7 @@
 package org.onap.policy.apex.model.eventmodel.concepts;
 
 import com.google.common.base.Strings;
+import com.google.gson.annotations.SerializedName;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
@@ -31,12 +32,6 @@ import java.util.Set;
 import java.util.SortedMap;
 import java.util.TreeMap;
 import java.util.TreeSet;
-import javax.xml.bind.Unmarshaller;
-import javax.xml.bind.annotation.XmlAccessType;
-import javax.xml.bind.annotation.XmlAccessorType;
-import javax.xml.bind.annotation.XmlElement;
-import javax.xml.bind.annotation.XmlRootElement;
-import javax.xml.bind.annotation.XmlType;
 import org.apache.commons.lang3.EnumUtils;
 import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
 import org.onap.policy.apex.model.basicmodel.concepts.AxConcept;
@@ -69,35 +64,22 @@ import org.onap.policy.common.utils.validation.Assertions;
  * is checked to ensure it matches the event parameter key on the event. Finally, the parent key of each parameter is
  * checked to ensure it matches the event key.
  */
-@XmlAccessorType(XmlAccessType.FIELD)
-@XmlRootElement(name = "apexEvent", namespace = "http://www.onap.org/policy/apex-pdp")
-@XmlType(name = "AxEvent", namespace = "http://www.onap.org/policy/apex-pdp", propOrder =
-    { "key", "nameSpace", "source", "target", "parameterMap", "toscaPolicyState"})
-
 public class AxEvent extends AxConcept {
     private static final long serialVersionUID = -1460388382582984269L;
 
     private static final String WHITESPACE_REGEXP = "\\s+$";
 
     /** The key of the event, unique in the Apex system. */
-    @XmlElement(name = "key", required = true)
     // CHECKSTYLE:OFF: checkstyle:VisibilityMonitor
     protected AxArtifactKey key;
     // CHECKSTYLE:ON: checkstyle:VisibilityMonitor
 
-    @XmlElement(required = true)
     private String nameSpace;
-
-    @XmlElement(required = true)
     private String source;
-
-    @XmlElement(required = true)
     private String target;
 
-    @XmlElement(name = "parameter", required = true)
+    @SerializedName("parameter")
     private Map<String, AxField> parameterMap;
-
-    @XmlElement(required = false)
     private String toscaPolicyState;
 
     /**
@@ -189,14 +171,10 @@ public class AxEvent extends AxConcept {
     }
 
     /**
-     * When an event is unmarshalled from disk or from the database, the parent key in the reference keys in its
-     * parameter map are not set. This method is called by JAXB after unmarshaling and is used to set the parent key of
-     * the {@link AxField} instances in the parameter map to be the key of the event that contains them.
-     *
-     * @param unmarshaler the unmarshaler that is unmarshaling the model
-     * @param parent the parent object of this object in the unmarshaler
+     * {@inheritDoc}.
      */
-    public void afterUnmarshal(final Unmarshaller unmarshaler, final Object parent) {
+    @Override
+    public void buildReferences() {
         for (final AxField parameter : parameterMap.values()) {
             parameter.getKey().setParentArtifactKey(key);
         }
diff --git a/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/AxEventModel.java b/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/AxEventModel.java
index bb4307604..b91712c9d 100644
--- a/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/AxEventModel.java
+++ b/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/AxEventModel.java
@@ -23,11 +23,6 @@
 package org.onap.policy.apex.model.eventmodel.concepts;
 
 import java.util.List;
-import javax.xml.bind.annotation.XmlAccessType;
-import javax.xml.bind.annotation.XmlAccessorType;
-import javax.xml.bind.annotation.XmlElement;
-import javax.xml.bind.annotation.XmlRootElement;
-import javax.xml.bind.annotation.XmlType;
 import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
 import org.onap.policy.apex.model.basicmodel.concepts.AxConcept;
 import org.onap.policy.apex.model.basicmodel.concepts.AxKey;
@@ -46,18 +41,10 @@ import org.onap.policy.common.utils.validation.Assertions;
  * <p>Validation runs {@link AxModel} validation on the model. In addition, the {@link AxContextSchemas} and
  * {@link AxEvents} validation is run on the context schemas and events in the model.
  */
-
-@XmlRootElement(name = "apexEventModel", namespace = "http://www.onap.org/policy/apex-pdp")
-@XmlAccessorType(XmlAccessType.FIELD)
-@XmlType(name = "AxEventModel", namespace = "http://www.onap.org/policy/apex-pdp", propOrder = { "schemas", "events" })
-
 public class AxEventModel extends AxModel {
     private static final long serialVersionUID = 8800599637708309945L;
 
-    @XmlElement(name = "schemas", required = true)
     private AxContextSchemas schemas;
-
-    @XmlElement(name = "events", required = true)
     private AxEvents events;
 
     /**
diff --git a/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/AxEvents.java b/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/AxEvents.java
index 26275a157..aac1562de 100644
--- a/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/AxEvents.java
+++ b/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/AxEvents.java
@@ -27,11 +27,6 @@ import java.util.Map.Entry;
 import java.util.NavigableMap;
 import java.util.Set;
 import java.util.TreeMap;
-import javax.xml.bind.Unmarshaller;
-import javax.xml.bind.annotation.XmlAccessType;
-import javax.xml.bind.annotation.XmlAccessorType;
-import javax.xml.bind.annotation.XmlElement;
-import javax.xml.bind.annotation.XmlType;
 import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
 import org.onap.policy.apex.model.basicmodel.concepts.AxConcept;
 import org.onap.policy.apex.model.basicmodel.concepts.AxConceptGetter;
@@ -52,17 +47,10 @@ import org.onap.policy.common.utils.validation.Assertions;
  * container. Each event entry is checked to ensure that its key and value are not null and that the key matches the key
  * in the map value. Each event entry is then validated individually.
  */
-@XmlAccessorType(XmlAccessType.FIELD)
-@XmlType(name = "AxEvents", namespace = "http://www.onap.org/policy/apex-pdp", propOrder =
-    { "key", "eventMap" })
-
 public class AxEvents extends AxConcept implements AxConceptGetter<AxEvent> {
     private static final long serialVersionUID = 4290442590545820316L;
 
-    @XmlElement(name = "key", required = true)
     private AxArtifactKey key;
-
-    @XmlElement(required = true)
     private Map<AxArtifactKey, AxEvent> eventMap;
 
     /**
@@ -108,21 +96,6 @@ public class AxEvents extends AxConcept implements AxConceptGetter<AxEvent> {
     }
 
     /**
-     * When a model is unmarshalled from disk or from the database, the event map is returned as a raw hash map. This
-     * method is called by JAXB after unmarshaling and is used to convert the hash map to a {@link NavigableMap} so that
-     * it will work with the {@link AxConceptGetter} interface.
-     *
-     * @param unmarshaler the unmarshaler that is unmarshaling the model
-     * @param parent the parent object of this object in the unmarshaler
-     */
-    public void afterUnmarshal(final Unmarshaller unmarshaler, final Object parent) {
-        // The map must be navigable to allow name and version searching, unmarshaling returns a hash map
-        final NavigableMap<AxArtifactKey, AxEvent> navigableEventMap = new TreeMap<>();
-        navigableEventMap.putAll(eventMap);
-        eventMap = navigableEventMap;
-    }
-
-    /**
      * {@inheritDoc}.
      */
     @Override
@@ -145,6 +118,14 @@ public class AxEvents extends AxConcept implements AxConceptGetter<AxEvent> {
     }
 
     /**
+     * {@inheritDoc}.
+     */
+    @Override
+    public void buildReferences() {
+        eventMap.values().stream().forEach(event -> event.buildReferences());
+    }
+
+    /**
      * Sets the key of the event container.
      *
      * @param key the event container key
diff --git a/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/AxField.java b/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/AxField.java
index 9f98a6253..26511c9d1 100644
--- a/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/AxField.java
+++ b/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/AxField.java
@@ -23,12 +23,6 @@
 package org.onap.policy.apex.model.eventmodel.concepts;
 
 import java.util.List;
-import javax.xml.bind.annotation.XmlAccessType;
-import javax.xml.bind.annotation.XmlAccessorType;
-import javax.xml.bind.annotation.XmlElement;
-import javax.xml.bind.annotation.XmlRootElement;
-import javax.xml.bind.annotation.XmlType;
-import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
 import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
 import org.onap.policy.apex.model.basicmodel.concepts.AxConcept;
 import org.onap.policy.apex.model.basicmodel.concepts.AxKey;
@@ -37,7 +31,6 @@ import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
 import org.onap.policy.apex.model.basicmodel.concepts.AxValidationMessage;
 import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
 import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult.ValidationResult;
-import org.onap.policy.apex.model.basicmodel.xml.AxReferenceKeyAdapter;
 import org.onap.policy.common.utils.validation.Assertions;
 
 /**
@@ -50,11 +43,6 @@ import org.onap.policy.common.utils.validation.Assertions;
  *
  * <p>Validation checks that the field key and the field schema reference key are not null.
  */
-@XmlAccessorType(XmlAccessType.FIELD)
-@XmlRootElement(name = "apexField", namespace = "http://www.onap.org/policy/apex-pdp")
-@XmlType(name = "AxField", namespace = "http://www.onap.org/policy/apex-pdp", propOrder =
-    { "key", "fieldSchemaKey", "optional" })
-
 public class AxField extends AxConcept {
     private static final String KEY_MAY_NOT_BE_NULL = "key may not be null";
     private static final String FIELD_SCHEMA_KEY_MAY_NOT_BE_NULL = "fieldSchemaKey may not be null";
@@ -64,14 +52,8 @@ public class AxField extends AxConcept {
     private static final int HASH_PRIME_0 = 1231;
     private static final int HASH_PRIME_1 = 1237;
 
-    @XmlElement(name = "key", required = true)
-    @XmlJavaTypeAdapter(AxReferenceKeyAdapter.class)
     private AxReferenceKey key;
-
-    @XmlElement(required = true)
     private AxArtifactKey fieldSchemaKey;
-
-    @XmlElement(required = false)
     private boolean optional;
 
     /**
diff --git a/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/AxInputField.java b/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/AxInputField.java
index 2626e8b25..6155c7186 100644
--- a/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/AxInputField.java
+++ b/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/AxInputField.java
@@ -21,20 +21,12 @@
 
 package org.onap.policy.apex.model.eventmodel.concepts;
 
-import javax.xml.bind.annotation.XmlAccessType;
-import javax.xml.bind.annotation.XmlAccessorType;
-import javax.xml.bind.annotation.XmlRootElement;
-import javax.xml.bind.annotation.XmlType;
 import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
 import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
 
 /**
  * This class specializes the {@link AxField} class for use as input fields on events.
  */
-@XmlAccessorType(XmlAccessType.FIELD)
-@XmlRootElement(name = "apexInputField", namespace = "http://www.onap.org/policy/apex-pdp")
-@XmlType(name = "AxInputField", namespace = "http://www.onap.org/policy/apex-pdp")
-
 public class AxInputField extends AxField {
     private static final long serialVersionUID = 2090324845463750391L;
 
diff --git a/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/AxOutputField.java b/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/AxOutputField.java
index a3e835202..7f3437617 100644
--- a/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/AxOutputField.java
+++ b/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/AxOutputField.java
@@ -21,20 +21,12 @@
 
 package org.onap.policy.apex.model.eventmodel.concepts;
 
-import javax.xml.bind.annotation.XmlAccessType;
-import javax.xml.bind.annotation.XmlAccessorType;
-import javax.xml.bind.annotation.XmlRootElement;
-import javax.xml.bind.annotation.XmlType;
 import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
 import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
 
 /**
  * This class specializes the {@link AxField} class for use as output fields on events.
  */
-@XmlAccessorType(XmlAccessType.FIELD)
-@XmlRootElement(name = "apexOutputField", namespace = "http://www.onap.org/policy/apex-pdp")
-@XmlType(name = "AxOutputField", namespace = "http://www.onap.org/policy/apex-pdp")
-
 public class AxOutputField extends AxField {
     private static final long serialVersionUID = 2090324845463750391L;
 
diff --git a/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/package-info.java b/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/package-info.java
index 7b20b3939..414d22d0e 100644
--- a/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/package-info.java
+++ b/model/event-model/src/main/java/org/onap/policy/apex/model/eventmodel/concepts/package-info.java
@@ -1,6 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2022 Nordix Foundation.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,12 +24,4 @@
  *
  * @author Liam Fallon (liam.fallon@ericsson.com)
  */
-
-@XmlSchema(namespace = "http://www.onap.org/policy/apex-pdp", elementFormDefault = XmlNsForm.QUALIFIED,
-        xmlns = { @XmlNs(namespaceURI = "http://www.onap.org/policy/apex-pdp", prefix = "") })
-
 package org.onap.policy.apex.model.eventmodel.concepts;
-
-import javax.xml.bind.annotation.XmlNs;
-import javax.xml.bind.annotation.XmlNsForm;
-import javax.xml.bind.annotation.XmlSchema;