content: /*
   * 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.calcite.avatica;
  
  import java.sql.SQLException;
  
  /**
   * Called at various points in the JDBC lifecycle.
   *
   * <p>Most drivers will use {@link HandlerImpl}, which provides no-op
   * implementations of all methods. You only need to override methods if you
   * need to achieve special effects.</p>
   */
  public interface Handler {
    /** Called by container when a connection is being created.
     *
     * <p>If the implementation of this method throws, the connection
     * will not be created.</p>
     *
     * @param connection Connection
     * @throws SQLException on error
     */
    void onConnectionInit(AvaticaConnection connection) throws SQLException;
  
    /** Called by container when a connection is being closed.
     *
     * <p>If the implementation of this method throws, the call to
     * {@link java.sql.Connection#close} that triggered this method will throw an
     * exception, but the connection will still be marked closed.</p>
     *
     * @param connection Connection
     */
    void onConnectionClose(AvaticaConnection connection);
  
    /** Called by container when a statement is being executed.
     *
     * <p>If the session would like the statement results stored in a temporary
     * table, {@code resultSink} is not null.
     * The provider must call its {@link ResultSink#toBeCompleted}
     * method at some point during execution (not necessarily before the call to
     * this method returns).</p>
     *
     * @param statement Statement
     * @param resultSink Place to put result of query. Null if container does not
     *                   want results stored to a temporary table
     * @throws RuntimeException on error
     */
    void onStatementExecute(
        AvaticaStatement statement,
        ResultSink resultSink);
  
    /** Called by container when a statement is being closed.
     *
     * <p>This method is called after marking the statement closed, and after
     * closing any open {@link java.sql.ResultSet} objects.</p>
     *
     * <p>If the implementation of this method throws, the call to
     * {@link java.sql.Statement#close} that triggered this method will throw an
     * exception, but the statement will still be marked closed.
     *
     * @param statement Statement
     * @throws RuntimeException on error
     */
    void onStatementClose(AvaticaStatement statement);
  
    /** Handler for temporary tables. */
    interface ResultSink {
      /** Registers a temporary table. */
      void toBeCompleted();
    }
  }
  
  // End Handler.java
  