Allow providers other than PolicyModelsProvider

[policy/models.git] / models-provider / src / main / java / org / onap / policy / models / provider / impl / AbstractModelsProvider.java

diff --git a/models-provider/src/main/java/org/onap/policy/models/provider/impl/AbstractModelsProvider.java b/models-provider/src/main/java/org/onap/policy/models/provider/impl/AbstractModelsProvider.java
new file mode 100644 (file)
index 0000000..818cc44
--- /dev/null
+++ b/models-provider/src/main/java/org/onap/policy/models/provider/impl/AbstractModelsProvider.java
@@ -0,0 +1,115 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2021 Nordix Foundation.
+ * ================================================================================
+ * 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.models.provider.impl;
+
+import java.io.Closeable;
+import java.util.Properties;
+import javax.ws.rs.core.Response;
+import lombok.Getter;
+import lombok.NonNull;
+import org.eclipse.persistence.config.PersistenceUnitProperties;
+import org.onap.policy.models.base.PfModelException;
+import org.onap.policy.models.dao.DaoParameters;
+import org.onap.policy.models.dao.PfDao;
+import org.onap.policy.models.dao.PfDaoFactory;
+import org.onap.policy.models.dao.impl.DefaultPfDao;
+import org.onap.policy.models.provider.PolicyModelsProviderParameters;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * This class provides an abstract models provider that can be used to initialise the database for any specialisation of
+ * the class.
+ */
+public abstract class AbstractModelsProvider implements Closeable {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(AbstractModelsProvider.class);
+
+    private final PolicyModelsProviderParameters parameters;
+
+    // Database connection and the DAO for reading and writing Policy Framework concepts
+    @Getter
+    private PfDao pfDao;
+
+    /**
+     * Constructor that takes the parameters.
+     *
+     * @param parameters the parameters for the provider
+     */
+    protected AbstractModelsProvider(@NonNull final PolicyModelsProviderParameters parameters) {
+        this.parameters = parameters;
+    }
+
+    /**
+     * Initialise the provider.
+     *
+     * @throws PfModelException in initialisation errors
+     */
+    public synchronized void init() throws PfModelException {
+        LOGGER.debug("opening the database connection to {} using persistence unit {}", parameters.getDatabaseUrl(),
+                parameters.getPersistenceUnit());
+
+        if (pfDao != null) {
+            String errorMessage = "provider is already initialized";
+            throw new PfModelException(Response.Status.NOT_ACCEPTABLE, errorMessage);
+        }
+
+        // Parameters for the DAO
+        final DaoParameters daoParameters = new DaoParameters();
+        daoParameters.setPluginClass(DefaultPfDao.class.getName());
+        daoParameters.setPersistenceUnit(parameters.getPersistenceUnit());
+
+        // @formatter:off
+        Properties jdbcProperties = new Properties();
+        jdbcProperties.setProperty(PersistenceUnitProperties.JDBC_DRIVER,   parameters.getDatabaseDriver());
+        jdbcProperties.setProperty(PersistenceUnitProperties.JDBC_URL,      parameters.getDatabaseUrl());
+        jdbcProperties.setProperty(PersistenceUnitProperties.JDBC_USER,     parameters.getDatabaseUser());
+        jdbcProperties.setProperty(PersistenceUnitProperties.JDBC_PASSWORD, parameters.getDatabasePassword());
+        // @formatter:on
+
+        daoParameters.setJdbcProperties(jdbcProperties);
+
+        try {
+            pfDao = new PfDaoFactory().createPfDao(daoParameters);
+            pfDao.init(daoParameters);
+        } catch (Exception exc) {
+            String errorMessage = "could not create Data Access Object (DAO) using url \"" + parameters.getDatabaseUrl()
+                    + "\" and persistence unit \"" + parameters.getPersistenceUnit() + "\"";
+
+            this.close();
+            throw new PfModelException(Response.Status.NOT_ACCEPTABLE, errorMessage, exc);
+        }
+    }
+
+    @Override
+    public synchronized void close() {
+        LOGGER.debug("closing the database connection to {} using persistence unit {}", parameters.getDatabaseUrl(),
+                parameters.getPersistenceUnit());
+
+        if (pfDao != null) {
+            pfDao.close();
+            pfDao = null;
+        }
+
+        LOGGER.debug("closed the database connection to {} using persistence unit {}", parameters.getDatabaseUrl(),
+                parameters.getPersistenceUnit());
+    }
+}