exec/jdbc/src/main/java/org/apache/drill/jdbc/Driver.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */
package org.apache.drill.jdbc;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.DriverPropertyInfo;
import java.sql.SQLException;
import java.util.Properties;

import org.apache.drill.common.util.GuavaPatcher;
import org.apache.drill.common.util.ProtobufPatcher;
import org.apache.drill.jdbc.impl.DriverImpl;


/**
 * Main class of Apache Drill JDBC driver.
 */
public class Driver implements java.sql.Driver {
  private static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(Driver.class);

  /** Delegate for everything except registration with DriverManager. */
  private final DriverImpl impl;


  // The following should be the last static initialization, so that any other
  // static initialization is completed before we create an instance and let
  // DriverManager access it:

  static {
    ProtobufPatcher.patch();
    GuavaPatcher.patch();
    // Upon loading of class, register an instance with DriverManager.
    try {
      DriverManager.registerDriver(new Driver());
    } catch (Error | SQLException e) {
      logger.warn("Error in registering Drill JDBC driver {}: {}", Driver.class, e, e);
    }
  }

  /**
   * Ensures that class is loaded.
   * <p>
   *   (Avoids extra instance of calling {@code new Driver();}; avoids verbosity
   *   of {@code Class.forName("org.apache.drill.jdbc.Driver");}.)
   * </p>
   */
  public static boolean load() {
    return true;
  }


  public Driver() {
    impl = new DriverImpl();
  }


  @Override
  public Connection connect( String url, Properties info ) throws SQLException {
    return impl.connect( url, info );
  }


  @Override
  public boolean acceptsURL( String url ) throws SQLException {
    return impl.acceptsURL( url );
  }

  @Override
  public DriverPropertyInfo[] getPropertyInfo( String url, Properties info )
     throws SQLException {
    return impl.getPropertyInfo( url,  info );
  }

  @Override
  public int getMajorVersion() {
    return impl.getMajorVersion();
  }

  @Override
  public int getMinorVersion() {
    return impl.getMinorVersion();
  }

  @Override
  public boolean jdbcCompliant() {
    return impl.jdbcCompliant();
  }

  @Override
  public java.util.logging.Logger getParentLogger() {
    return impl.getParentLogger();
  }

}