| /* |
| * 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.commons.dbutils.handlers; |
| |
| import java.sql.ResultSet; |
| import java.sql.SQLException; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| import org.apache.commons.dbutils.ResultSetHandler; |
| |
| /** |
| * <p> |
| * {@code ResultSetHandler} implementation that returns a Map. |
| * {@code ResultSet} rows are converted into objects (Vs) which are then stored |
| * in a Map under the given keys (Ks). |
| * </p> |
| * |
| * @param <K> the type of keys maintained by the returned map |
| * @param <V> the type of mapped values |
| * @see org.apache.commons.dbutils.ResultSetHandler |
| * @since DbUtils 1.3 |
| */ |
| public abstract class AbstractKeyedHandler<K, V> implements ResultSetHandler<Map<K, V>> { |
| |
| |
| /** |
| * Convert each row's columns into a Map and store then |
| * in a {@code Map} under {@code ResultSet.getObject(key)} key. |
| * @param rs {@code ResultSet} to process. |
| * @return A {@code Map}, never {@code null}. |
| * @throws SQLException if a database access error occurs |
| * @see org.apache.commons.dbutils.ResultSetHandler#handle(java.sql.ResultSet) |
| */ |
| @Override |
| public Map<K, V> handle(final ResultSet rs) throws SQLException { |
| final Map<K, V> result = createMap(); |
| while (rs.next()) { |
| result.put(createKey(rs), createRow(rs)); |
| } |
| return result; |
| } |
| |
| /** |
| * This factory method is called by {@code handle()} to create the Map |
| * to store records in. This implementation returns a {@code HashMap} |
| * instance. |
| * |
| * @return Map to store records in |
| */ |
| protected Map<K, V> createMap() { |
| return new HashMap<>(); |
| } |
| |
| /** |
| * This factory method is called by {@code handle()} to retrieve the |
| * key value from the current {@code ResultSet} row. |
| * @param rs ResultSet to create a key from |
| * @return K from the configured key column name/index |
| * @throws SQLException if a database access error occurs |
| */ |
| protected abstract K createKey(ResultSet rs) throws SQLException; |
| |
| /** |
| * This factory method is called by {@code handle()} to store the |
| * current {@code ResultSet} row in some object. |
| * @param rs ResultSet to create a row from |
| * @return V object created from the current row |
| * @throws SQLException if a database access error occurs |
| */ |
| protected abstract V createRow(ResultSet rs) throws SQLException; |
| |
| } |