bq.jpa.demo.version.service.VersionService.java Source code

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Here is the source code for bq.jpa.demo.version.service.VersionService.java

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/*
Copyright (c) 2014 (Jonathan Q. Bo) 
    
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 shall be used for Good, not Evil.
    
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 bq.jpa.demo.version.service;

import java.util.ArrayList;
import java.util.List;

import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.Query;
import javax.persistence.TypedQuery;

import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import bq.jpa.demo.query.domain.ResultViewer;
import bq.jpa.demo.version.domain.Address;
import bq.jpa.demo.version.domain.Employee;

/**
 * <b>  </b>
 *
 * <p> </p>
 *
 * @author Jonathan Q. Bo (jonathan.q.bo@gmail.com)
 *
 * Created at Feb 16, 2014 4:35:14 PM
 *
 */
@Service
public class VersionService {

    @PersistenceContext
    private EntityManager em;

    @Transactional
    public void doCreate() {
        List<Employee> employees = new ArrayList<>();
        for (int i = 0; i < 10; i++) {
            Employee employee = new Employee();
            employee.setName("employee_" + i);
            employee.setSalary(100f * i);
            em.persist(employee);
            employees.add(employee);
        }

        List<Address> addresses = new ArrayList<>();
        for (int i = 0; i < 10; i++) {
            Address address = new Address();
            address.setState("NY");
            address.setCity("New York");
            address.setStreet("street_" + i);
            em.persist(address);
            addresses.add(address);
        }

        for (int i = 0; i < 10; i++) {
            addresses.get(i).setEmployee(employees.get(i));
        }
    }

    /**
     * can change version automatically
     */
    @Transactional
    public void doUpdate() {
        TypedQuery<Employee> query = em.createQuery("SELECT e FROM jpa_version_employee e", Employee.class);
        List<Employee> results = query.getResultList();
        for (Employee e : results)
            e.setName("new_employee");
    }

    /**
     * batch way by query language cannot change version
     */
    @Transactional
    public void doUpdateByQL() {
        Query update = em.createQuery("UPDATE jpa_version_employee e SET e.name= CONCAT('new',e.name)");
        update.executeUpdate();
    }

    /**
     * batch way need change version by ourselves
     */
    @Transactional
    public void doUpdateVersionByQL() {
        Query update = em.createQuery(
                "UPDATE jpa_version_employee e SET e.name= CONCAT('new',e.name), e.version=e.version+1");
        update.executeUpdate();
    }

    /**
     * modify related address will not change employee's version automatically
     */
    @Transactional
    public void doUpdateAddress() {
        TypedQuery<Address> query = em.createQuery("SELECT a FROM jpa_version_address a", Address.class);
        List<Address> results = query.getResultList();
        for (int i = 0; i < results.size(); i++) {
            Address address = results.get(i);
            address.setState("MI");
            address.setCity("Lansing");
        }
    }

    @Transactional
    public void showResult() {
        TypedQuery<Employee> query = em.createQuery("SELECT e FROM jpa_version_employee e", Employee.class);
        List<Employee> results = query.getResultList();
        ResultViewer.showResult(results, "show all employees");
    }

}