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.apex.examples.distributeddistinct;
  
  import java.sql.PreparedStatement;
  import java.sql.ResultSet;
  import java.sql.SQLException;
  import java.sql.Statement;
  import java.util.HashSet;
  import java.util.Set;
  
  import org.apache.apex.malhar.lib.algo.UniqueValueCount;
  import org.apache.apex.malhar.lib.util.KeyValPair;
  
  /**
   * This operator demonstrates {@link UniqueValueCountAppender} given that the keys and values of the preceding {@link UniqueValueCount} operator
   * are both integers. <br/>
   * It will keep track of the number of all the unique values emitted per key since the application starts.
   *
   * @since 1.0.4
   */
  public class IntegerUniqueValueCountAppender extends UniqueValueCountAppender<Integer>
  {
    @Override
    public Object processResultSet(ResultSet resultSet)
    {
      Set<Integer> valSet = new HashSet<Integer>();
      try {
        while (resultSet.next()) {
          valSet.add(resultSet.getInt(1));
        }
        return valSet;
      } catch (SQLException e) {
        throw new RuntimeException("while processing the result set", e);
      }
    }
  
    @Override
    protected void prepareGetStatement(PreparedStatement getStatement, Object key) throws SQLException
    {
      getStatement.setInt(1, (Integer)key);
    }
  
    @Override
    protected void preparePutStatement(PreparedStatement putStatement, Object key, Object value) throws SQLException
    {
      @SuppressWarnings("unchecked")
      Set<Integer> valueSet = (Set<Integer>)value;
      for (Integer val : valueSet) {
        @SuppressWarnings("unchecked")
        Set<Integer> currentVals = (Set<Integer>)get(key);
        if (!currentVals.contains(val)) {
          batch = true;
          putStatement.setInt(1, (Integer)key);
          putStatement.setInt(2, val);
          putStatement.setLong(3, windowID);
          putStatement.addBatch();
        }
      }
    }
  
    @Override
    public void endWindow()
    {
      try {
        Statement stmt = store.getConnection().createStatement();
        String keySetQuery = "SELECT DISTINCT col1 FROM " + tableName;
        ResultSet resultSet = stmt.executeQuery(keySetQuery);
        while (resultSet.next()) {
          int val = resultSet.getInt(1);
          @SuppressWarnings("unchecked")
          Set<Integer> valSet = (Set<Integer>)cacheManager.get(val);
          output.emit(new KeyValPair<Object, Object>(val, valSet.size()));
        }
      } catch (SQLException e) {
        throw new RuntimeException("While emitting tuples", e);
      }
    }
  }
  