Merge pull request #5876 from the-java-guy/master

BAEL-2343
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Loredana Crusoveanu 2018-12-09 21:20:12 +02:00 committed by GitHub
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package com.baeldung.hibernate.operations;
import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;
import com.baeldung.hibernate.pojo.Movie;
/**
*
*Class to illustrate the usage of EntityManager API.
*/
public class HibernateOperations {
private static final EntityManagerFactory emf;
/**
* Static block for creating EntityManagerFactory. The Persistence class looks for META-INF/persistence.xml in the classpath.
*/
static {
emf = Persistence.createEntityManagerFactory("com.baeldung.movie_catalog");
}
/**
* Static method returning EntityManager.
* @return EntityManager
*/
public static EntityManager getEntityManager() {
return emf.createEntityManager();
}
/**
* Saves the movie entity into the database. Here we are using Application Managed EntityManager, hence should handle transactions by ourselves.
*/
public void saveMovie() {
EntityManager em = HibernateOperations.getEntityManager();
em.getTransaction()
.begin();
Movie movie = new Movie();
movie.setId(1L);
movie.setMovieName("The Godfather");
movie.setReleaseYear(1972);
movie.setLanguage("English");
em.persist(movie);
em.getTransaction()
.commit();
}
/**
* Method to illustrate the querying support in EntityManager when the result is a single object.
* @return Movie
*/
public Movie queryForMovieById() {
EntityManager em = HibernateOperations.getEntityManager();
Movie movie = (Movie) em.createQuery("SELECT movie from Movie movie where movie.id = ?1")
.setParameter(1, new Long(1L))
.getSingleResult();
return movie;
}
/**
* Method to illustrate the querying support in EntityManager when the result is a list.
* @return
*/
public List<?> queryForMovies() {
EntityManager em = HibernateOperations.getEntityManager();
List<?> movies = em.createQuery("SELECT movie from Movie movie where movie.language = ?1")
.setParameter(1, "English")
.getResultList();
return movies;
}
/**
* Method to illustrate the usage of find() method.
* @param movieId
* @return Movie
*/
public Movie getMovie(Long movieId) {
EntityManager em = HibernateOperations.getEntityManager();
Movie movie = em.find(Movie.class, new Long(movieId));
return movie;
}
/**
* Method to illustrate the usage of merge() function.
*/
public void mergeMovie() {
EntityManager em = HibernateOperations.getEntityManager();
Movie movie = getMovie(1L);
em.detach(movie);
movie.setLanguage("Italian");
em.getTransaction()
.begin();
em.merge(movie);
em.getTransaction()
.commit();
}
/**
* Method to illustrate the usage of remove() function.
*/
public void removeMovie() {
EntityManager em = HibernateOperations.getEntityManager();
em.getTransaction()
.begin();
Movie movie = em.find(Movie.class, new Long(1L));
em.remove(movie);
em.getTransaction()
.commit();
}
}

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package com.baeldung.hibernate.pojo;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
@Entity
@Table(name = "MOVIE")
public class Movie {
@Id
private Long id;
private String movieName;
private Integer releaseYear;
private String language;
public String getMovieName() {
return movieName;
}
public void setMovieName(String movieName) {
this.movieName = movieName;
}
public Integer getReleaseYear() {
return releaseYear;
}
public void setReleaseYear(Integer releaseYear) {
this.releaseYear = releaseYear;
}
public String getLanguage() {
return language;
}
public void setLanguage(String language) {
this.language = language;
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
}

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<?xml version="1.0" encoding="UTF-8" ?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
version="2.0">
<persistence-unit name="com.baeldung.movie_catalog">
<description>Hibernate EntityManager Demo</description>
<class>com.baeldung.hibernate.pojo.Movie</class>
<exclude-unlisted-classes>true</exclude-unlisted-classes>
<properties>
<property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5Dialect"/>
<property name="hibernate.hbm2ddl.auto" value="update"/>
<property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
<property name="javax.persistence.jdbc.url" value="jdbc:mysql://127.0.0.1:3306/moviecatalog"/>
<property name="javax.persistence.jdbc.user" value="root"/>
<property name="javax.persistence.jdbc.password" value="root"/>
</properties>
</persistence-unit>
</persistence>