1 files changed, 287 insertions, 0 deletions
diff --git a/services/services-engine/src/main/java/org/onap/policy/apex/service/parameters/engineservice/EngineServiceParametersJSONAdapter.java b/services/services-engine/src/main/java/org/onap/policy/apex/service/parameters/engineservice/EngineServiceParametersJSONAdapter.java
new file mode 100644
index 000000000..9fca2fd19
--- /dev/null
+++ b/services/services-engine/src/main/java/org/onap/policy/apex/service/parameters/engineservice/EngineServiceParametersJSONAdapter.java
@@ -0,0 +1,287 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. 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.service.parameters.engineservice;
+
+import java.lang.reflect.Type;
+import java.util.Map.Entry;
+
+import org.onap.policy.apex.context.impl.schema.java.JavaSchemaHelperParameters;
+import org.onap.policy.apex.context.parameters.ContextParameters;
+import org.onap.policy.apex.context.parameters.DistributorParameters;
+import org.onap.policy.apex.context.parameters.LockManagerParameters;
+import org.onap.policy.apex.context.parameters.PersistorParameters;
+import org.onap.policy.apex.context.parameters.SchemaHelperParameters;
+import org.onap.policy.apex.context.parameters.SchemaParameters;
+import org.onap.policy.apex.core.engine.EngineParameters;
+import org.onap.policy.apex.core.engine.ExecutorParameters;
+import org.onap.policy.apex.model.basicmodel.service.AbstractParameters;
+import org.onap.policy.apex.service.parameters.ApexParameterRuntimeException;
+import org.slf4j.ext.XLogger;
+import org.slf4j.ext.XLoggerFactory;
+
+import com.google.gson.JsonDeserializationContext;
+import com.google.gson.JsonDeserializer;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParseException;
+import com.google.gson.JsonSerializationContext;
+import com.google.gson.JsonSerializer;
+
+/**
+ * This class deserializes engine service parameters from JSON format. The class produces an
+ * {@link EngineServiceParameters} instance from incoming JSON read from a configuration file in
+ * JSON format.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class EngineServiceParametersJSONAdapter
+        implements JsonSerializer<EngineParameters>, JsonDeserializer<EngineParameters> {
+    private static final XLogger LOGGER = XLoggerFactory.getXLogger(EngineServiceParametersJSONAdapter.class);
+
+    private static final String PARAMETER_CLASS_NAME = "parameterClassName";
+
+    // @formatter:off
+    private static final String CONTEXT_PARAMETERS      = "contextParameters";
+    private static final String DISTRIBUTOR_PARAMETERS  = "distributorParameters";
+    private static final String LOCK_MANAGER_PARAMETERS = "lockManagerParameters";
+    private static final String PERSISTOR_PARAMETERS    = "persistorParameters";
+    private static final String SCHEMA_PARAMETERS       = "schemaParameters";
+    private static final String EXECUTOR_PARAMETERS     = "executorParameters";
+    // @formatter:on
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see com.google.gson.JsonSerializer#serialize(java.lang.Object, java.lang.reflect.Type,
+     * com.google.gson.JsonSerializationContext)
+     */
+    @Override
+    public JsonElement serialize(final EngineParameters src, final Type typeOfSrc,
+            final JsonSerializationContext context) {
+        final String returnMessage = "serialization of Apex parameters to Json is not supported";
+        LOGGER.error(returnMessage);
+        throw new ApexParameterRuntimeException(returnMessage);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see com.google.gson.JsonDeserializer#deserialize(com.google.gson.JsonElement,
+     * java.lang.reflect.Type, com.google.gson.JsonDeserializationContext)
+     */
+    @Override
+    public EngineParameters deserialize(final JsonElement json, final Type typeOfT,
+            final JsonDeserializationContext context) throws JsonParseException {
+        final JsonObject engineParametersJsonObject = json.getAsJsonObject();
+
+        final EngineParameters engineParameters = new EngineParameters();
+
+        // Deserialise context parameters, they may be a subclass of the ContextParameters class
+        engineParameters.setContextParameters(
+                (ContextParameters) context.deserialize(engineParametersJsonObject, ContextParameters.class));
+
+        // Context parameter wrangling
+        getContextParameters(engineParametersJsonObject, engineParameters, context);
+
+        // Executor parameter wrangling
+        getExecutorParameters(engineParametersJsonObject, engineParameters, context);
+
+        return engineParameters;
+    }
+
+    /**
+     * Get the context parameters for Apex.
+     *
+     * @param engineParametersJsonObject The input JSON
+     * @param engineParameters The output parameters
+     * @param context the JSON context
+     */
+    private void getContextParameters(final JsonObject engineParametersJsonObject,
+            final EngineParameters engineParameters, final JsonDeserializationContext context) {
+        final JsonElement contextParametersElement = engineParametersJsonObject.get(CONTEXT_PARAMETERS);
+
+        // Context parameters are optional so if the element does not exist, just return
+        if (contextParametersElement == null) {
+            return;
+        }
+
+        // We do this because the JSON parameters may be for a subclass of ContextParameters
+        final ContextParameters contextParameters =
+                (ContextParameters) deserializeParameters(CONTEXT_PARAMETERS, contextParametersElement, context);
+
+        // We know this will work because if the context parameters was not a Json object, the
+        // previous deserializeParameters() call would not have worked
+        final JsonObject contextParametersObject = engineParametersJsonObject.get(CONTEXT_PARAMETERS).getAsJsonObject();
+
+        // Now get the distributor, lock manager, and persistence parameters
+        final JsonElement distributorParametersElement = contextParametersObject.get(DISTRIBUTOR_PARAMETERS);
+        if (distributorParametersElement != null) {
+            contextParameters
+                    .setDistributorParameters((DistributorParameters) deserializeParameters(DISTRIBUTOR_PARAMETERS,
+                            distributorParametersElement, context));
+        }
+
+        final JsonElement lockManagerParametersElement = contextParametersObject.get(LOCK_MANAGER_PARAMETERS);
+        if (lockManagerParametersElement != null) {
+            contextParameters
+                    .setLockManagerParameters((LockManagerParameters) deserializeParameters(LOCK_MANAGER_PARAMETERS,
+                            lockManagerParametersElement, context));
+        }
+
+        final JsonElement persistorParametersElement = contextParametersObject.get(PERSISTOR_PARAMETERS);
+        if (persistorParametersElement != null) {
+            contextParameters.setPersistorParameters((PersistorParameters) deserializeParameters(PERSISTOR_PARAMETERS,
+                    persistorParametersElement, context));
+        }
+
+        // Schema Handler parameter wrangling
+        getSchemaHandlerParameters(contextParametersObject, contextParameters, context);
+
+        // Get the engine plugin parameters
+        engineParameters.setContextParameters(contextParameters);
+    }
+
+    /**
+     * Get the executor parameters for Apex.
+     *
+     * @param engineParametersJsonObject The input JSON
+     * @param engineParameters The output parameters
+     * @param context the JSON context
+     */
+    private void getExecutorParameters(final JsonObject engineParametersJsonObject,
+            final EngineParameters engineParameters, final JsonDeserializationContext context) {
+        final JsonElement executorParametersElement = engineParametersJsonObject.get(EXECUTOR_PARAMETERS);
+
+        // Executor parameters are mandatory so if the element does not exist throw an exception
+        if (executorParametersElement == null) {
+            final String returnMessage = "no \"" + EXECUTOR_PARAMETERS
+                    + "\" entry found in parameters, at least one executor parameter entry must be specified";
+            LOGGER.error(returnMessage);
+            throw new ApexParameterRuntimeException(returnMessage);
+        }
+
+        // Deserialize the executor parameters
+        final JsonObject executorParametersJsonObject =
+                engineParametersJsonObject.get(EXECUTOR_PARAMETERS).getAsJsonObject();
+
+        for (final Entry<String, JsonElement> executorEntries : executorParametersJsonObject.entrySet()) {
+            final ExecutorParameters executorParameters =
+                    (ExecutorParameters) deserializeParameters(EXECUTOR_PARAMETERS + ':' + executorEntries.getKey(),
+                            executorEntries.getValue(), context);
+            engineParameters.getExecutorParameterMap().put(executorEntries.getKey(), executorParameters);
+        }
+    }
+
+    /**
+     * Get the schema parameters for Apex.
+     *
+     * @param contextParametersJsonObject The input JSON
+     * @param contextParameters The output parameters
+     * @param context the JSON context
+     */
+    private void getSchemaHandlerParameters(final JsonObject contextParametersJsonObject,
+            final ContextParameters contextParameters, final JsonDeserializationContext context) {
+        final JsonElement schemaParametersElement = contextParametersJsonObject.get(SCHEMA_PARAMETERS);
+
+        // Insert the default Java schema helper
+        contextParameters.getSchemaParameters().getSchemaHelperParameterMap()
+                .put(SchemaParameters.DEFAULT_SCHEMA_FLAVOUR, new JavaSchemaHelperParameters());
+
+        // Context parameters are optional so if the element does not exist, just return
+        if (schemaParametersElement == null) {
+            return;
+        }
+
+        // Deserialize the executor parameters
+        final JsonObject schemaHelperParametersJsonObject =
+                contextParametersJsonObject.get(SCHEMA_PARAMETERS).getAsJsonObject();
+
+        for (final Entry<String, JsonElement> schemaHelperEntries : schemaHelperParametersJsonObject.entrySet()) {
+            contextParameters.getSchemaParameters().getSchemaHelperParameterMap().put(schemaHelperEntries.getKey(),
+                    (SchemaHelperParameters) deserializeParameters(
+                            SCHEMA_PARAMETERS + ':' + schemaHelperEntries.getKey(), schemaHelperEntries.getValue(),
+                            context));
+        }
+    }
+
+    /**
+     * Deserialize a parameter object that's a superclass of the AbstractParameters class.
+     *
+     * @param parametersLabel Label to use for error messages
+     * @param parametersElement The JSON object holding the parameters
+     * @param context The GSON context
+     * @return the parameters
+     * @throws ApexParameterRuntimeException on errors reading the parameters
+     */
+    private AbstractParameters deserializeParameters(final String parametersLabel, final JsonElement parametersElement,
+            final JsonDeserializationContext context) throws ApexParameterRuntimeException {
+        JsonObject parametersObject = null;
+
+        // Check that the JSON element is a JSON object
+        if (parametersElement.isJsonObject()) {
+            parametersObject = parametersElement.getAsJsonObject();
+        } else {
+            final String returnMessage = "value of \"" + parametersLabel + "\" entry is not a parameter JSON object";
+            LOGGER.error(returnMessage);
+            throw new ApexParameterRuntimeException(returnMessage);
+        }
+
+        // Get the parameter class name for instantiation in deserialization
+        final JsonElement parameterClassNameElement = parametersObject.get(PARAMETER_CLASS_NAME);
+        if (parameterClassNameElement == null) {
+            final String returnMessage =
+                    "could not find field \"" + PARAMETER_CLASS_NAME + "\" in \"" + parametersLabel + "\" entry";
+            LOGGER.error(returnMessage);
+            throw new ApexParameterRuntimeException(returnMessage);
+        }
+
+        // Check the parameter is a JSON primitive
+        if (!parameterClassNameElement.isJsonPrimitive()) {
+            final String returnMessage = "value for field \"" + PARAMETER_CLASS_NAME + "\" in \"" + parametersLabel
+                    + "\" entry is not a plain string";
+            LOGGER.error(returnMessage);
+            throw new ApexParameterRuntimeException(returnMessage);
+        }
+
+        // Check the parameter has a value
+        final String parameterClassName = parameterClassNameElement.getAsString();
+        if (parameterClassName == null || parameterClassName.trim().length() == 0) {
+            final String returnMessage = "value for field \"" + PARAMETER_CLASS_NAME + "\" in \"" + parametersLabel
+                    + "\" entry is not specified or is blank";
+            LOGGER.error(returnMessage);
+            throw new ApexParameterRuntimeException(returnMessage);
+        }
+
+        // Deserialize the parameters using GSON
+        AbstractParameters parameters = null;
+        try {
+            parameters = context.deserialize(parametersObject, Class.forName(parameterClassName));
+        } catch (JsonParseException | ClassNotFoundException e) {
+            final String returnMessage =
+                    "failed to deserialize the parameters for \"" + parametersLabel + "\" " + "to parameter class \""
+                            + parameterClassName + "\"\n" + e.getClass().getCanonicalName() + ": " + e.getMessage();
+            LOGGER.error(returnMessage, e);
+            throw new ApexParameterRuntimeException(returnMessage, e);
+        }
+
+        return parameters;
+    }
+}