/** * The MIT License * Copyright © 2014-2019 Ilkka Seppälä * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ package com.iluwatar.datamapper; import java.util.Optional; import org.apache.log4j.Logger; /** * The Data Mapper (DM) is a layer of software that separates the in-memory objects from the * database. Its responsibility is to transfer data between the two and also to isolate them from * each other. With Data Mapper the in-memory objects needn't know even that there's a database * present; they need no SQL interface code, and certainly no knowledge of the database schema. (The * database schema is always ignorant of the objects that use it.) Since it's a form of Mapper , * Data Mapper itself is even unknown to the domain layer. *
* The below example demonstrates basic CRUD operations: Create, Read, Update, and Delete.
*
*/
public final class App {
private static Logger log = Logger.getLogger(App.class);
private static final String STUDENT_STRING = "App.main(), student : ";
/**
* Program entry point.
*
* @param args command line args.
*/
public static void main(final String... args) {
/* Create new data mapper for type 'first' */
final StudentDataMapper mapper = new StudentDataMapperImpl();
/* Create new student */
Student student = new Student(1, "Adam", 'A');
/* Add student in respectibe store */
mapper.insert(student);
log.debug(STUDENT_STRING + student + ", is inserted");
/* Find this student */
final Optional