Adding JSON Schema support in APEX-PDP

More details can be found here:
https://wiki.onap.org/display/DW/JSON+Schema+support+in+APEX-PDP

A separate review will be raised as part of POLICY-4292 with a reference
example on how to use the JSON Schema.

Change-Id: I903d48969c6c5a24c63b8465b2412ed0b75b9351
Issue-ID: POLICY-4291
Signed-off-by: a.sreekumar <ajith.sreekumar@bell.ca>
(cherry picked from commit c354fba3fb87ebe21a7fbb2a15268ccc9d033fbd)

12 files changed, 810 insertions, 0 deletions

diff --git a/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/pom.xml b/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/pom.xml
new file mode 100644
index 000000000..979ab49cf
--- /dev/null
+++ b/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/pom.xml
@@ -0,0 +1,44 @@
+<!--
+  ============LICENSE_START=======================================================
+   Copyright (C) 2022 Bell Canada. 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.
+
+  SPDX-License-Identifier: Apache-2.0
+  ============LICENSE_END=========================================================
+-->
+<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>org.onap.policy.apex-pdp.plugins.plugins-context.plugins-context-schema</groupId>
+        <artifactId>plugins-context-schema</artifactId>
+        <version>2.5.5-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>plugins-context-schema-json</artifactId>
+    <name>${project.artifactId}</name>
+    <description>[${project.parent.artifactId}] Plugin for schemas using JSON</description>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.worldturner.medeia</groupId>
+            <artifactId>medeia-validator-gson</artifactId>
+            <version>1.1.1</version>
+        </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+</project>
diff --git a/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/main/java/org/onap/policy/apex/plugins/context/schema/json/JsonSchemaHelper.java b/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/main/java/org/onap/policy/apex/plugins/context/schema/json/JsonSchemaHelper.java
new file mode 100644
index 000000000..4896e5d4a
--- /dev/null
+++ b/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/main/java/org/onap/policy/apex/plugins/context/schema/json/JsonSchemaHelper.java
@@ -0,0 +1,122 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2022 Bell Canada. 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.plugins.context.schema.json;
+
+import com.google.gson.Gson;
+import com.google.gson.JsonElement;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonWriter;
+import com.worldturner.medeia.api.SchemaSource;
+import com.worldturner.medeia.api.StringInputSource;
+import com.worldturner.medeia.api.StringSchemaSource;
+import com.worldturner.medeia.api.gson.MedeiaGsonApi;
+import com.worldturner.medeia.schema.validation.SchemaValidator;
+import java.io.StringWriter;
+import java.util.List;
+import java.util.Map;
+import org.onap.policy.apex.context.ContextRuntimeException;
+import org.onap.policy.apex.context.impl.schema.AbstractSchemaHelper;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKey;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextSchema;
+
+/**
+ * This class is the implementation of the {@link org.onap.policy.apex.context.SchemaHelper} interface for JSON schema.
+ */
+public class JsonSchemaHelper extends AbstractSchemaHelper {
+
+    private static final Gson gson = new Gson();
+
+    private MedeiaGsonApi api = new MedeiaGsonApi();
+    private SchemaValidator validator;
+
+    @Override
+    public void init(final AxKey userKey, final AxContextSchema schema) {
+        super.init(userKey, schema);
+
+        try {
+            SchemaSource source = new StringSchemaSource(schema.getSchema());
+            validator = api.loadSchema(source);
+        } catch (final Exception e) {
+            final String resultSting = userKey.getId() + ": json context schema \"" + schema.getId()
+                + "\" schema is invalid, schema: " + schema.getSchema();
+            throw new ContextRuntimeException(resultSting, e);
+        }
+    }
+
+    @Override
+    public Object createNewInstance(final String stringValue) {
+        return unmarshal(stringValue);
+    }
+
+    @Override
+    public Object createNewInstance(final Object incomingObject) {
+        if (incomingObject instanceof JsonElement) {
+            final var elementJsonString = gson.toJson((JsonElement) incomingObject);
+
+            return createNewInstance(elementJsonString);
+        } else {
+            final var returnString =
+                getUserKey().getId() + ": the object \"" + incomingObject + "\" is not an instance of JsonObject";
+            throw new ContextRuntimeException(returnString);
+        }
+    }
+
+    @Override
+    public Object unmarshal(Object object) {
+        // If an object is already in the correct format, just carry on
+        if (passThroughObject(object)) {
+            return object;
+        }
+        var objectString = (String) object;
+        JsonReader reader = api.createJsonReader(validator, new StringInputSource(objectString));
+        return gson.fromJson(reader, Object.class);
+    }
+
+    @Override
+    public String marshal2String(Object schemaObject) {
+        StringWriter stringWriter = new StringWriter();
+        validateAndDecode(schemaObject, stringWriter);
+        return stringWriter.toString();
+    }
+
+    @Override
+    public Object marshal2Object(Object schemaObject) {
+        return validateAndDecode(schemaObject, new StringWriter());
+    }
+
+    private JsonElement validateAndDecode(Object schemaObject, StringWriter stringWriter) {
+        JsonWriter jsonWriter = api.createJsonWriter(validator, stringWriter);
+        jsonWriter.setIndent("  "); // to enable pretty print
+        JsonElement jsonObj = gson.toJsonTree(schemaObject);
+        gson.toJson(jsonObj, jsonWriter);
+        return jsonObj;
+    }
+
+    /**
+     * Check if we can pass this object straight through encoding or decoding.
+     *
+     * @param object the object to check
+     * @return true if it's a straight pass through
+     */
+    private boolean passThroughObject(final Object object) {
+        return (object instanceof JsonElement || object instanceof Map || object instanceof List);
+    }
+}
diff --git a/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/main/java/org/onap/policy/apex/plugins/context/schema/json/JsonSchemaHelperParameters.java b/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/main/java/org/onap/policy/apex/plugins/context/schema/json/JsonSchemaHelperParameters.java
new file mode 100644
index 000000000..0e275130d
--- /dev/null
+++ b/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/main/java/org/onap/policy/apex/plugins/context/schema/json/JsonSchemaHelperParameters.java
@@ -0,0 +1,30 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2022 Bell Canada. 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.plugins.context.schema.json;
+
+import org.onap.policy.apex.context.parameters.SchemaHelperParameters;
+
+public class JsonSchemaHelperParameters extends SchemaHelperParameters {
+
+    public JsonSchemaHelperParameters() {
+        this.setSchemaHelperPluginClass(JsonSchemaHelper.class.getName());
+    }
+}
diff --git a/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/test/java/org/onap/policy/apex/plugins/context/schema/json/CommonTestData.java b/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/test/java/org/onap/policy/apex/plugins/context/schema/json/CommonTestData.java
new file mode 100644
index 000000000..ce03678c9
--- /dev/null
+++ b/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/test/java/org/onap/policy/apex/plugins/context/schema/json/CommonTestData.java
@@ -0,0 +1,115 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2022 Bell Canada. 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.plugins.context.schema.json;
+
+import java.io.IOException;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.onap.policy.apex.context.SchemaHelper;
+import org.onap.policy.apex.context.impl.schema.SchemaHelperFactory;
+import org.onap.policy.apex.context.parameters.ContextParameterConstants;
+import org.onap.policy.apex.context.parameters.SchemaParameters;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKey;
+import org.onap.policy.apex.model.basicmodel.service.ModelService;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextSchema;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextSchemas;
+import org.onap.policy.common.parameters.ParameterService;
+import org.onap.policy.common.utils.coder.StandardCoder;
+import org.onap.policy.common.utils.resources.TextFileUtils;
+
+public class CommonTestData {
+
+    protected static final String VERSION = "0.0.1";
+    protected static final String JSON = "JSON";
+    protected static final String TEST_ID = "testId";
+    protected final AxKey testKey = new AxArtifactKey("JsonTest", VERSION);
+    protected AxContextSchemas schemas;
+    protected final StandardCoder coder = new StandardCoder();
+
+    protected static final String BOOLEAN_SCHEMA =
+        "{\"$schema\": \"http://json-schema.org/draft-07/schema#\",\"type\": \"boolean\"}";
+    protected static final String BOOLEAN_DATA = "true";
+    protected static final String NULL_SCHEMA =
+        "{\"$schema\":\"http://json-schema.org/draft-07/schema#\",\"type\":\"null\"}";
+    protected static final String NULL_DATA = "null";
+    protected static String COMMONHEADERTYPE_DRAFT04;
+    protected static String COMMONHEADERTYPE_DRAFT07;
+    protected static String COMMONHEADERTYPE_WITH_OPTIONAL;
+    protected static String COMMONHEADER;
+    protected static String MEASUREMENTGROUPS_TYPE;
+    protected static String MEASUREMENTGROUPS;
+
+    /**
+     * Setup before all tests.
+     */
+    @BeforeClass
+    public static void setUpBeforeClass() throws IOException {
+        COMMONHEADERTYPE_DRAFT04 =
+            TextFileUtils.getTextFileAsString("src/test/resources/schema/commonHeaderType_draft04.json");
+        COMMONHEADERTYPE_DRAFT07 =
+            TextFileUtils.getTextFileAsString("src/test/resources/schema/commonHeaderType_draft07.json");
+        COMMONHEADERTYPE_WITH_OPTIONAL =
+            TextFileUtils.getTextFileAsString("src/test/resources/schema/commonHeaderTypeWithOptional.json");
+        COMMONHEADER =
+            TextFileUtils.getTextFileAsString("src/test/resources/data/commonHeader.json").replaceAll("\r", "").trim();
+        MEASUREMENTGROUPS_TYPE =
+            TextFileUtils.getTextFileAsString("src/test/resources/schema/measurementGroupsType.json");
+        MEASUREMENTGROUPS = TextFileUtils.getTextFileAsString("src/test/resources/data/measurementGroups.json")
+            .replaceAll("\r", "").trim();
+    }
+
+    /**
+     * Setup before test.
+     */
+    @Before
+    public void setUp() {
+        schemas = new AxContextSchemas(new AxArtifactKey("JsonSchema", VERSION));
+        ModelService.registerModel(AxContextSchemas.class, schemas);
+
+        SchemaParameters schemaParameters = new SchemaParameters();
+        schemaParameters.setName(ContextParameterConstants.SCHEMA_GROUP_NAME);
+        schemaParameters.getSchemaHelperParameterMap().put(JSON, new JsonSchemaHelperParameters());
+        ParameterService.register(schemaParameters);
+    }
+
+    /**
+     * Teardown after test.
+     */
+    @After
+    public void tearDown() {
+        ParameterService.deregister(ContextParameterConstants.SCHEMA_GROUP_NAME);
+        ModelService.clear();
+    }
+
+    /**
+     * Method to create JsonSchemaHelper instance from schema content.
+     *
+     * @param schema the schema content as string
+     * @return schemaHelper instance
+     */
+    protected SchemaHelper createSchema(String schema) {
+        final AxContextSchema jsonSchema = new AxContextSchema(new AxArtifactKey("SchemaTest", VERSION), JSON, schema);
+        schemas.getSchemasMap().put(jsonSchema.getKey(), jsonSchema);
+        return new SchemaHelperFactory().createSchemaHelper(testKey, jsonSchema.getKey());
+    }
+}
diff --git a/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/test/java/org/onap/policy/apex/plugins/context/schema/json/JsonSchemaHelperMarshalTest.java b/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/test/java/org/onap/policy/apex/plugins/context/schema/json/JsonSchemaHelperMarshalTest.java
new file mode 100644
index 000000000..15458199a
--- /dev/null
+++ b/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/test/java/org/onap/policy/apex/plugins/context/schema/json/JsonSchemaHelperMarshalTest.java
@@ -0,0 +1,133 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2022 Bell Canada. 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.plugins.context.schema.json;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+import com.google.gson.JsonArray;
+import com.google.gson.JsonObject;
+import com.worldturner.medeia.api.ValidationFailedException;
+import java.util.ArrayList;
+import java.util.Map;
+import org.junit.Test;
+import org.onap.policy.common.utils.coder.CoderException;
+
+public class JsonSchemaHelperMarshalTest extends CommonTestData {
+
+    /**
+     * Test Boolean.
+     */
+    @Test
+    public void testBooleanMarshal() {
+        var schemaHelper = createSchema(BOOLEAN_SCHEMA);
+        assertThat(schemaHelper.marshal2String(Boolean.TRUE)).isEqualTo("true");
+    }
+
+    /**
+     * Test null.
+     */
+    @Test
+    public void testNullMarshal() {
+        var schemaHelper = createSchema(NULL_SCHEMA);
+        assertThat(schemaHelper.marshal2String(null)).isEqualTo("null");
+    }
+
+    /**
+     * Test Array.
+     *
+     * @throws CoderException the coder exception
+     */
+    @Test
+    public void testArrayMarshal() throws CoderException {
+        var schemaHelper = createSchema(MEASUREMENTGROUPS_TYPE);
+        var object = coder.decode(MEASUREMENTGROUPS, Object.class);
+        assertThat(object).isInstanceOf(ArrayList.class);
+        var marshalledString = schemaHelper.marshal2String(object);
+        assertThat(marshalledString).isEqualTo(MEASUREMENTGROUPS);
+        var marshalledObject = schemaHelper.marshal2Object(object);
+        assertThat(marshalledObject).isInstanceOf(JsonArray.class);
+    }
+
+    /**
+     * Test Object marshal valid scenario using JSON Schema draft 04.
+     *
+     * @throws CoderException the coderException
+     */
+    @Test
+    public void testObjectSchemaDraft04_valid() throws CoderException {
+        var dataAsObject = coder.decode(COMMONHEADER, Map.class);
+        var dataReturned = validateAndMarshal(COMMONHEADERTYPE_DRAFT04, dataAsObject, true);
+        assertThat(dataReturned).isEqualTo(COMMONHEADER);
+    }
+
+    /**
+     * Test Object marshal valid scenario using JSON Schema draft 07.
+     *
+     * @throws CoderException the coderException
+     */
+    @Test
+    public void testObjectSchemaDraft07_valid() throws CoderException {
+        var dataAsObject = coder.decode(COMMONHEADER, Map.class);
+        var dataReturned = validateAndMarshal(COMMONHEADERTYPE_DRAFT07, dataAsObject, true);
+        assertThat(dataReturned).isEqualTo(COMMONHEADER);
+        assertThat(validateAndMarshal(COMMONHEADERTYPE_DRAFT07, dataAsObject, false)).isInstanceOf(JsonObject.class);
+    }
+
+    /**
+     * Test Object marshal invalid - required field missing scenario.
+     *
+     * @throws CoderException the coderException
+     */
+    @Test
+    public void testObjectSchema_fieldMissing() throws CoderException {
+        var dataAsObject = coder.decode(COMMONHEADER, Map.class);
+        dataAsObject.remove(TEST_ID);
+        assertThatThrownBy(() -> validateAndMarshal(COMMONHEADERTYPE_DRAFT07, dataAsObject, true))
+            .isInstanceOf(ValidationFailedException.class)
+            .hasMessageContaining("Required property testId is missing from object");
+    }
+
+    /**
+     * Test Object marshal with optional field.
+     *
+     * @throws CoderException the coderException
+     */
+    @Test
+    public void testObjectSchema_OptionalField() throws CoderException {
+        var dataAsObject = coder.decode(COMMONHEADER, Map.class);
+        var dataAsjsonObject = coder.decode(COMMONHEADER, JsonObject.class);
+        dataAsObject.remove(TEST_ID);
+        dataAsjsonObject.remove(TEST_ID);
+        var dataReturned = validateAndMarshal(COMMONHEADERTYPE_WITH_OPTIONAL, dataAsObject, false);
+        assertThat(dataReturned).isEqualTo(dataAsjsonObject);
+    }
+
+    private Object validateAndMarshal(String schemaDef, Object obj, boolean marshalAsString) {
+        var schemaHelper = createSchema(schemaDef);
+        if (marshalAsString) {
+            return schemaHelper.marshal2String(obj);
+        } else {
+            return schemaHelper.marshal2Object(obj);
+        }
+    }
+
+}
diff --git a/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/test/java/org/onap/policy/apex/plugins/context/schema/json/JsonSchemaHelperUnmarshalTest.java b/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/test/java/org/onap/policy/apex/plugins/context/schema/json/JsonSchemaHelperUnmarshalTest.java
new file mode 100644
index 000000000..11c8638de
--- /dev/null
+++ b/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/test/java/org/onap/policy/apex/plugins/context/schema/json/JsonSchemaHelperUnmarshalTest.java
@@ -0,0 +1,166 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2022 Bell Canada. 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.plugins.context.schema.json;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+import com.google.gson.JsonObject;
+import com.worldturner.medeia.api.ValidationFailedException;
+import java.util.ArrayList;
+import java.util.Map;
+import org.junit.Test;
+import org.onap.policy.apex.context.ContextRuntimeException;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextSchema;
+import org.onap.policy.common.utils.coder.CoderException;
+
+public class JsonSchemaHelperUnmarshalTest extends CommonTestData {
+
+    /**
+     * Test Boolean.
+     */
+    @Test
+    public void testBooleanUnmarshal() {
+        var schemaHelper = createSchema(BOOLEAN_SCHEMA);
+        assertThat(schemaHelper.createNewInstance(BOOLEAN_DATA)).isInstanceOf(Boolean.class).isEqualTo(Boolean.TRUE);
+    }
+
+    /**
+     * Test null.
+     */
+    @Test
+    public void testNullUnmarshal() {
+        var schemaHelper = createSchema(NULL_SCHEMA);
+        assertThat(schemaHelper.createNewInstance(NULL_DATA)).isEqualTo(null);
+    }
+
+    /**
+     * Test Array.
+     */
+    @Test
+    public void testArrayUnmarshal() {
+        var schemaHelper = createSchema(MEASUREMENTGROUPS_TYPE);
+        var obj = schemaHelper.createNewInstance(MEASUREMENTGROUPS);
+        assertThat(obj).isInstanceOf(ArrayList.class);
+    }
+
+    /**
+     * Test invlaid schema.
+     */
+    @Test
+    public void testSchemaInvalid() {
+        String schemaDef = "{\"type\": \"object\"}";
+        final AxContextSchema jsonSchema =
+            new AxContextSchema(new AxArtifactKey("JsonObject", VERSION), JSON, schemaDef);
+        assertThatThrownBy(() -> new JsonSchemaHelper().init(testKey, jsonSchema))
+            .isInstanceOf(ContextRuntimeException.class).hasMessageContaining("schema is invalid");
+    }
+
+    /**
+     * Test Object unmarshal valid scenario using JSON Schema draft 04.
+     *
+     * @throws CoderException the coderException
+     */
+    @Test
+    public void testObjectSchemaDraft04_valid() throws CoderException {
+        var dataAsObject = coder.decode(COMMONHEADER, Map.class);
+        var dataReturned = validateAndUnmarshal(COMMONHEADERTYPE_DRAFT04, COMMONHEADER);
+        assertThat(dataReturned).isEqualTo(dataAsObject);
+    }
+
+    /**
+     * Test Object unmarshal valid scenario using JSON Schema draft 07.
+     *
+     * @throws CoderException the coderException
+     */
+    @Test
+    public void testObjectSchemaDraft07_valid() throws CoderException {
+        var dataAsObject = coder.decode(COMMONHEADER, Map.class);
+        var dataReturned = validateAndUnmarshal(COMMONHEADERTYPE_DRAFT07, COMMONHEADER);
+        assertThat(dataReturned).isEqualTo(dataAsObject);
+    }
+
+    /**
+     * Test Object unmarshal invalid scenario using JSON Schema draft 07.
+     *
+     * @throws CoderException the coderException
+     */
+    @Test
+    public void testObjectSchemaDraft07_invalid() throws CoderException {
+        var dataAsObject = coder.decode(COMMONHEADER, JsonObject.class);
+        dataAsObject.addProperty("requestId", "abcd");
+        assertThatThrownBy(() -> validateAndUnmarshal(COMMONHEADERTYPE_DRAFT07, dataAsObject))
+            .isInstanceOf(ValidationFailedException.class)
+            .hasMessageContaining("Pattern ^[0-9]*-[0-9]*$ is not contained in text");
+    }
+
+    /**
+     * Test createInstance using invalid format data.
+     *
+     * @throws CoderException the coderException
+     */
+    @Test
+    public void testCreateNewInstanceInvalid() throws CoderException {
+        var dataAsObject = coder.decode(COMMONHEADER, Map.class);
+        assertThatThrownBy(() -> validateAndUnmarshal(COMMONHEADERTYPE_DRAFT07, dataAsObject))
+            .isInstanceOf(ContextRuntimeException.class).hasMessageContaining("not an instance of JsonObject");
+    }
+
+    /**
+     * Test Object unmarshal invalid - required field missing scenario.
+     *
+     * @throws CoderException the coderException
+     */
+    @Test
+    public void testObjectSchema_fieldMissing() throws CoderException {
+        var dataAsObject = coder.decode(COMMONHEADER, JsonObject.class);
+        dataAsObject.remove(TEST_ID);
+        assertThatThrownBy(() -> validateAndUnmarshal(COMMONHEADERTYPE_DRAFT07, dataAsObject))
+            .isInstanceOf(ValidationFailedException.class)
+            .hasMessageContaining("Required property testId is missing from object");
+    }
+
+    /**
+     * Test Object unmarshal with optional field.
+     *
+     * @throws CoderException the coderException
+     */
+    @Test
+    public void testObjectSchema_OptionalField() throws CoderException {
+        var dataAsObject = coder.decode(COMMONHEADER, Map.class);
+        var dataAsjsonObject = coder.decode(COMMONHEADER, JsonObject.class);
+        dataAsObject.remove(TEST_ID);
+        dataAsjsonObject.remove(TEST_ID);
+        var dataReturned = validateAndUnmarshal(COMMONHEADERTYPE_WITH_OPTIONAL, dataAsjsonObject);
+        assertThat(dataReturned).isEqualTo(dataAsObject);
+    }
+
+    private Object validateAndUnmarshal(String schemaDef, Object data) {
+        var schemaHelper = createSchema(schemaDef);
+        if (data instanceof String) {
+            return schemaHelper.createNewInstance((String) data);
+        } else {
+            return schemaHelper.createNewInstance(data);
+        }
+    }
+
+}
diff --git a/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/test/resources/data/commonHeader.json b/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/test/resources/data/commonHeader.json
new file mode 100644
index 000000000..d3393cc63
--- /dev/null
+++ b/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/test/resources/data/commonHeader.json
@@ -0,0 +1,6 @@
+{
+  "requestId": "123456-1000",
+  "subRequestId": "sub-123456-1000",
+  "originatorId": "sdnc",
+  "testId": 212.2
+}
diff --git a/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/test/resources/data/measurementGroups.json b/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/test/resources/data/measurementGroups.json
new file mode 100644
index 000000000..e615968ac
--- /dev/null
+++ b/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/test/resources/data/measurementGroups.json
@@ -0,0 +1,34 @@
+[
+  {
+    "measurementGroup": {
+      "measurementTypes": [
+        {
+          "measurementType": "countera"
+        },
+        {
+          "measurementType": "counterb"
+        }
+      ],
+      "managedObjectDNsBasic": [
+        {
+          "DN": "dna"
+        },
+        {
+          "DN": "dnb"
+        }
+      ]
+    }
+  },
+  {
+    "measurementGroup": {
+      "measurementTypes": [
+        {
+          "measurementType": "counterc"
+        },
+        {
+          "measurementType": "counterd"
+        }
+      ]
+    }
+  }
+]
diff --git a/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/test/resources/schema/commonHeaderTypeWithOptional.json b/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/test/resources/schema/commonHeaderTypeWithOptional.json
new file mode 100644
index 000000000..d8d994fda
--- /dev/null
+++ b/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/test/resources/schema/commonHeaderTypeWithOptional.json
@@ -0,0 +1,23 @@
+{
+  "$schema": "http://json-schema.org/draft-04/schema#",
+  "type": "object",
+  "properties": {
+    "requestId": {
+      "type": "string"
+    },
+    "subRequestId": {
+      "type": "string"
+    },
+    "originatorId": {
+      "type": "string"
+    },
+    "testId": {
+      "type": "integer"
+    }
+  },
+  "required": [
+    "requestId",
+    "subRequestId",
+    "originatorId"
+  ]
+}
diff --git a/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/test/resources/schema/commonHeaderType_draft04.json b/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/test/resources/schema/commonHeaderType_draft04.json
new file mode 100644
index 000000000..de1c05b6f
--- /dev/null
+++ b/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/test/resources/schema/commonHeaderType_draft04.json
@@ -0,0 +1,24 @@
+{
+  "$schema": "http://json-schema.org/draft-04/schema#",
+  "type": "object",
+  "properties": {
+    "requestId": {
+      "type": "string"
+    },
+    "subRequestId": {
+      "type": "string"
+    },
+    "originatorId": {
+      "type": "string"
+    },
+    "testId": {
+      "type": "number"
+    }
+  },
+  "required": [
+    "requestId",
+    "subRequestId",
+    "originatorId",
+    "testId"
+  ]
+}
diff --git a/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/test/resources/schema/commonHeaderType_draft07.json b/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/test/resources/schema/commonHeaderType_draft07.json
new file mode 100644
index 000000000..94558ffe5
--- /dev/null
+++ b/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/test/resources/schema/commonHeaderType_draft07.json
@@ -0,0 +1,52 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "title": "Root",
+  "type": "object",
+  "required": [
+    "requestId",
+    "subRequestId",
+    "originatorId",
+    "testId"
+  ],
+  "properties": {
+    "requestId": {
+      "$id": "#root/requestId",
+      "title": "Requestid",
+      "type": "string",
+      "default": "",
+      "examples": [
+        "123456-1000"
+      ],
+      "pattern": "^[0-9]*-[0-9]*$"
+    },
+    "subRequestId": {
+      "$id": "#root/subRequestId",
+      "title": "Subrequestid",
+      "type": "string",
+      "default": "",
+      "examples": [
+        "sub-123456-1000"
+      ],
+      "pattern": "^.*$"
+    },
+    "originatorId": {
+      "$id": "#root/originatorId",
+      "title": "Originatorid",
+      "type": "string",
+      "default": "",
+      "examples": [
+        "sdnc"
+      ],
+      "pattern": "^.*$"
+    },
+    "testId": {
+      "$id": "#root/testId",
+      "title": "Testid",
+      "type": "number",
+      "examples": [
+        212.2
+      ],
+      "default": 0
+    }
+  }
+}
diff --git a/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/test/resources/schema/measurementGroupsType.json b/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/test/resources/schema/measurementGroupsType.json
new file mode 100644
index 000000000..41e598f93
--- /dev/null
+++ b/plugins/plugins-context/plugins-context-schema/plugins-context-schema-json/src/test/resources/schema/measurementGroupsType.json
@@ -0,0 +1,61 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "type": "array",
+  "default": [],
+  "items": {
+    "type": "object",
+    "required": [
+      "measurementGroup"
+    ],
+    "properties": {
+      "measurementGroup": {
+        "type": "object",
+        "required": [
+          "measurementTypes"
+        ],
+        "properties": {
+          "measurementTypes": {
+            "type": "array",
+            "default": [],
+            "items": {
+              "type": "object",
+              "required": [
+                "measurementType"
+              ],
+              "properties": {
+                "measurementType": {
+                  "type": "string",
+                  "default": "",
+                  "examples": [
+                    "countera"
+                  ],
+                  "pattern": "^.*$"
+                }
+              }
+            }
+          },
+          "managedObjectDNsBasic": {
+            "type": "array",
+            "default": [],
+            "items": {
+              "type": "object",
+              "required": [
+                "DN"
+              ],
+              "properties": {
+                "DN": {
+                  "type": "string",
+                  "default": "",
+                  "examples": [
+                    "dna"
+                  ],
+                  "pattern": "^.*$"
+                }
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+}