01e489c77b
* Reduces checkstyle errors in dao * Reduces checkstyle errors in data-bus * Reduces checkstyle errors in data-locality * Reduces checkstyle errors in data-mapper * Reduces checkstyle errors in data-transfer-object * Reduces checkstyle errors in decorator
85 lines
3.1 KiB
Java
85 lines
3.1 KiB
Java
/*
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* The MIT License
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* Copyright © 2014-2019 Ilkka Seppälä
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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package com.iluwatar.datamapper;
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import java.util.Optional;
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import org.slf4j.Logger;
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import org.slf4j.LoggerFactory;
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/**
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* The Data Mapper (DM) is a layer of software that separates the in-memory objects from the
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* database. Its responsibility is to transfer data between the two and also to isolate them from
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* each other. With Data Mapper the in-memory objects needn't know even that there's a database
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* present; they need no SQL interface code, and certainly no knowledge of the database schema. (The
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* database schema is always ignorant of the objects that use it.) Since it's a form of Mapper ,
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* Data Mapper itself is even unknown to the domain layer.
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*
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* <p>The below example demonstrates basic CRUD operations: Create, Read, Update, and Delete.
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*/
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public final class App {
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private static Logger log = LoggerFactory.getLogger(App.class);
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private static final String STUDENT_STRING = "App.main(), student : ";
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/**
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* Program entry point.
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*
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* @param args command line args.
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*/
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public static void main(final String... args) {
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/* Create new data mapper for type 'first' */
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final StudentDataMapper mapper = new StudentDataMapperImpl();
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/* Create new student */
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Student student = new Student(1, "Adam", 'A');
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/* Add student in respectibe store */
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mapper.insert(student);
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log.debug(STUDENT_STRING + student + ", is inserted");
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/* Find this student */
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final Optional<Student> studentToBeFound = mapper.find(student.getStudentId());
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log.debug(STUDENT_STRING + studentToBeFound + ", is searched");
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/* Update existing student object */
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student = new Student(student.getStudentId(), "AdamUpdated", 'A');
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/* Update student in respectibe db */
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mapper.update(student);
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log.debug(STUDENT_STRING + student + ", is updated");
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log.debug(STUDENT_STRING + student + ", is going to be deleted");
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/* Delete student in db */
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mapper.delete(student);
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}
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private App() {
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}
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}
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