mike@159: /*
mike@159:  * Copyright 2020 Mike Becker. All rights reserved.
mike@159:  *
mike@159:  * Redistribution and use in source and binary forms, with or without
mike@159:  * modification, are permitted provided that the following conditions are met:
mike@159:  *
mike@159:  * 1. Redistributions of source code must retain the above copyright
mike@159:  * notice, this list of conditions and the following disclaimer.
mike@159:  *
mike@159:  * 2. Redistributions in binary form must reproduce the above copyright
mike@159:  * notice, this list of conditions and the following disclaimer in the
mike@159:  * documentation and/or other materials provided with the distribution.
mike@159:  *
mike@159:  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
mike@159:  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
mike@159:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
mike@159:  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
mike@159:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
mike@159:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
mike@159:  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
mike@159:  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
mike@159:  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
mike@159:  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
mike@159:  *
mike@159:  */
mike@159: 
mike@159: package de.uapcore.lightpit.dao
mike@159: 
mike@159: import java.sql.PreparedStatement
mike@159: import java.sql.ResultSet
mike@159: import java.sql.Types
mike@159: 
mike@159: abstract class AbstractDao<T> {
mike@159: 
mike@159:     abstract fun mapResult(rs: ResultSet): T
mike@159: 
mike@159:     protected fun list(stmt: PreparedStatement): List<T> {
mike@159:         return sequence {
mike@159:             stmt.executeQuery().use { result ->
mike@159:                 while (result.next()) yield(mapResult(result))
mike@159:             }
mike@159:         }.toList()
mike@159:     }
mike@159: 
mike@159:     protected fun find(stmt: PreparedStatement): T? {
mike@159:         stmt.executeQuery().use { result ->
mike@159:             return if (result.next()) {
mike@159:                 mapResult(result)
mike@159:             } else {
mike@159:                 null
mike@159:             }
mike@159:         }
mike@159:     }
mike@159: 
mike@159:     // TODO: create PreparedStatement abstraction that provides some features
mike@159: 
mike@159:     // TODO: remove the following legacy code helper function
mike@159:     protected fun <T> setForeignKeyOrNull(stmt: PreparedStatement, index: Int, instance: T?, keyGetter: (obj: T) -> Int) {
mike@159:         if (instance == null) {
mike@159:             stmt.setNull(index, Types.INTEGER)
mike@159:         } else {
mike@159:             stmt.setInt(index, keyGetter(instance))
mike@159:         }
mike@159:     }
mike@159: }