0、前言

目的：旨在记录jpa操作数据库，持久层的hibernate框架实现了jpa

项目结构：

1、导入pom文件

<dependencies>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-core</artifactId>
        <version>5.2.17.Final</version>
    </dependency>

    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.36</version>
    </dependency>

    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
    </dependency>
</dependencies>

2、编写核心配置文件persistence.xml

文件要求的目录是：src/main/resources/META-INF

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1"
             xmlns="http://xmlns.jcp.org/xml/ns/persistence"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">

    <persistence-unit name="hibernate-jpa">
        <!-- 1、jpa是一个规范，是一个接口，它没有任何的具体实现，这里需要指定一个jpa具体实现 -->
        <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>

        <properties>
            <!-- 2、连接数据库的信息 -->
            <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver" />
            <property name="javax.persistence.jdbc.url" value="jdbc:mysql://10.10.50.160:3306/test?characterEncoding=UTF-8" />
            <property name="javax.persistence.jdbc.user" value="root" />
            <property name="javax.persistence.jdbc.password" value="abc123456#" />

            <!-- 3、jpa的具体实现，hibernate的基本属性 -->
            <property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5InnoDBDialect" />
            <property name="hibernate.show_sql" value="true" />
            <property name="hibernate.format_sql" value="true" />
            <property name="hibernate.hbm2ddl.auto" value="update" />
        </properties>
    </persistence-unit>

</persistence>

3、编写实体类

package cn.itcast.orm.entity;

import javax.persistence.*;

/**
 * @author jiangl
 * @ClassName Book.java
 * @Description 实体类，图书
 * @createTime 2022年06月03日 11:21
 */

@Entity
@Table(name = "t_book")
public class Book
{
    @Id
    @Column(name = "bid")
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private  Integer id;//主键

    @Column(name = "bname")
    private String name;//图书名称

    @Column(name = "author")
    private String author;//作者

    @Column(name = "price")
    private double price;//价格

    public Integer getId()
    {
        return id;
    }

    public void setId(Integer id)
    {
        this.id = id;
    }

    public String getName()
    {
        return name;
    }

    public void setName(String name)
    {
        this.name = name;
    }

    public String getAuthor()
    {
        return author;
    }

    public void setAuthor(String author)
    {
        this.author = author;
    }

    public double getPrice()
    {
        return price;
    }

    public void setPrice(double price)
    {
        this.price = price;
    }

    @Override
    public String toString()
    {
        return "Book{" + "id=" + id + ", name='" + name + '\'' + ", author='" + author + '\'' + ", price=" + price + '}';
    }
}

4、编写测试类

import cn.itcast.orm.entity.Book;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.junit.Test;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.EntityTransaction;
import javax.persistence.Persistence;

/**
 * @author jiangl
 * @ClassName BookTest.java
 * @Description 测试类
 * @createTime 2022年06月03日 12:46
 */
public class BookTest
{
    @Test
    public void testSave()
    {
        //1.创建entityManagerFactory -- 参数为<persistence-unit name="hibernate-jpa">的name值
        EntityManagerFactory entityManagerFactory = Persistence.createEntityManagerFactory("hibernate-jpa");

        //2.创建EntityManager
        EntityManager entityManager = entityManagerFactory.createEntityManager();

        //3.开启事务处理
        EntityTransaction transaction = entityManager.getTransaction();
        transaction.begin();

        //4.执行数据的CRUD
        Book book = new Book();
        book.setName("c#从入门到精通");
        book.setAuthor("传智播客");
        book.setPrice(9.8);
        entityManager.persist(book);

        //5.提交事务
        transaction.commit();

        //6.关闭entityManager和entityManagerFactory
        entityManager.close();
        entityManagerFactory.close();

    }
}

5、测试

保存数据成功。

标签：hibernate,name,author,jpa,demo,price,import,public,persistence
来源： https://www.cnblogs.com/jspider/p/16347146.html