org.neo4j.jdbc.bolt.BoltNeo4jDatabaseMetaData Maven / Gradle / Ivy

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Bolt implementation for the Neo4j JDBC Driver
There is a newer version: 5.0.0
/*
 * Copyright (c) 2016 LARUS Business Automation [http://www.larus-ba.it]
 * 
 * This file is part of the "LARUS Integration Framework for Neo4j".
 * 

 * The "LARUS Integration Framework for Neo4j" is 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.
 * 

 * Created on 01/03/2016
 */
package org.neo4j.jdbc.bolt;

import org.neo4j.driver.Record;
import org.neo4j.driver.Session;
import org.neo4j.driver.Result;
import org.neo4j.jdbc.Neo4jDatabaseMetaData;
import org.neo4j.jdbc.bolt.impl.BoltNeo4jConnectionImpl;
import org.neo4j.jdbc.metadata.Column;
import org.neo4j.jdbc.metadata.Table;
import org.neo4j.jdbc.utils.Neo4jInvocationHandler;

import java.lang.reflect.Proxy;
import java.sql.DatabaseMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * Provides metadata
 *
 * @author AgileLARUS
 * @since 3.0.0
 */
public class BoltNeo4jDatabaseMetaData extends Neo4jDatabaseMetaData {

	private static final String DB_PROPERTIES_QUERY = "MATCH (n:`%s`) WITH n LIMIT %d UNWIND keys(n) as key RETURN collect(distinct key) as keys";

	/**
	 * Used for some extra logging (for example in the constructor)
	 */
	private static final Logger LOGGER = Logger.getLogger(BoltNeo4jDatabaseMetaData.class.getCanonicalName());

	private List functions;

	public BoltNeo4jDatabaseMetaData(BoltNeo4jConnectionImpl connection) {
		super(connection);

		// compute database metadata: version, tables == labels, columns = properties (by label)
		if (connection != null) {
			Session session = null;
			try {
				session = connection.newNeo4jSession();
				getDatabaseVersion(session);
				getDatabaseLabels(session);
				getDatabaseProperties(session);
				functions = callDbmsFunctions(session);
			} catch (Exception e) {
				LOGGER.log(Level.SEVERE, e.getMessage(), e);
			}finally{
				BoltNeo4jUtils.closeSafely(session, LOGGER);
			}
		}
	}

	public static DatabaseMetaData newInstance(boolean debug, BoltNeo4jConnectionImpl connection) {
		DatabaseMetaData dbmd = new BoltNeo4jDatabaseMetaData(connection);
		return (DatabaseMetaData) Proxy.newProxyInstance(BoltNeo4jDatabaseMetaData.class.getClassLoader(), new Class[] { DatabaseMetaData.class },
				new Neo4jInvocationHandler(dbmd, debug));
	}

	private void getDatabaseVersion(Session session) {
		Result rs = session.run("CALL dbms.components() yield name,versions WITH * WHERE name=\"Neo4j Kernel\" RETURN versions[0] AS version");
		if (rs != null && rs.hasNext()) {
			Record record = rs.next();
			if (record.containsKey("version")) {
				databaseVersion = record.get("version").asString();
			}
		}
	}

	private void getDatabaseLabels(Session session) {
		Result rs = session.run("CALL db.labels() yield label return label");
		if (rs != null) {
			while (rs.hasNext()) {
				Record record = rs.next();
				this.databaseLabels.add(new Table(record.get("label").asString()));
			}
		}
	}

	private void getDatabaseProperties(Session session) {
		if (this.databaseLabels != null) {
			for (Table databaseLabel : this.databaseLabels) {
				Result rs = session.run(String.format(DB_PROPERTIES_QUERY, databaseLabel.getTableName(), Neo4jDatabaseMetaData.PROPERTY_SAMPLE_SIZE));
				if (rs != null) {
					cycleResultSetToSetDatabaseProperties(rs, databaseLabel);
				}
			}
		}
	}

	private void cycleResultSetToSetDatabaseProperties(Result rs, Table databaseLabel) {
		while (rs.hasNext()) {
			Record record = rs.next();
			List