RowProcessor.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.commons.dbutils;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;
import java.util.Map;

/**
 * <code>RowProcessor</code> implementations convert 
 * <code>ResultSet</code> rows into various other objects.  Implementations
 * can extend <code>BasicRowProcessor</code> to protect themselves
 * from changes to this interface. 
 * 
 * @see BasicRowProcessor
 */
public interface RowProcessor {

    /**
     * Create an <code>Object[]</code> from the column values in one 
     * <code>ResultSet</code> row.  The <code>ResultSet</code> should be 
     * positioned on a valid row before passing it to this method.  
     * Implementations of this method must not alter the row position of 
     * the <code>ResultSet</code>. 
     *
     * @param rs ResultSet that supplies the array data
     * @throws SQLException if a database access error occurs
     * @return the newly created array
     */
    public Object[] toArray(ResultSet rs) throws SQLException;

    /**
     * Create a JavaBean from the column values in one <code>ResultSet</code> 
     * row.  The <code>ResultSet</code> should be positioned on a valid row before
     * passing it to this method.  Implementations of this method must not
     * alter the row position of the <code>ResultSet</code>.
     * @param <T> The type of bean to create
     * @param rs ResultSet that supplies the bean data
     * @param type Class from which to create the bean instance
     * @throws SQLException if a database access error occurs
     * @return the newly created bean
     */
    public <T> T toBean(ResultSet rs, Class<T> type) throws SQLException;

    /**
     * Create a <code>List</code> of JavaBeans from the column values in all 
     * <code>ResultSet</code> rows.  <code>ResultSet.next()</code> should 
     * <strong>not</strong> be called before passing it to this method.
     * @param <T> The type of bean to create
     * @param rs ResultSet that supplies the bean data
     * @param type Class from which to create the bean instance
     * @throws SQLException if a database access error occurs
     * @return A <code>List</code> of beans with the given type in the order 
     * they were returned by the <code>ResultSet</code>.
     */
    public <T> List<T> toBeanList(ResultSet rs, Class<T> type) throws SQLException;

    /**
     * Create a <code>Map</code> from the column values in one 
     * <code>ResultSet</code> row.  The <code>ResultSet</code> should be 
     * positioned on a valid row before
     * passing it to this method.  Implementations of this method must not
     * alter the row position of the <code>ResultSet</code>.
     *
     * @param rs ResultSet that supplies the map data
     * @throws SQLException if a database access error occurs
     * @return the newly created Map
     */
    public Map<String, Object> toMap(ResultSet rs) throws SQLException;

}