Hibernate——简单的增、删、改、查操作

思路：

1.导入hibernate jar包

2.导入mysql jar包

3.创建数据库

4.创建java实体类

5.编写hibernate.cfg.xml配置文件

6.编写dao类

目录：

数据表：

实体类：

package online.shixun.model;

import java.util.Date;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

/**
 * 实体类
 * @author Tom
 *
 */
@Entity
@Table(name = "commodity")
public class Commodity {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)//主键自增
    private Integer id;

    @Column(name = "createDate")
    private Date createDate;//创建日期

    @Column(name = "described")
    private String describe;//商品描述

    @Column(name = "modifyDate")
    private Date modifyDate;//修改日期

    @Column(name = "name")
    private String name;//商品名称

    //构造函数
    public Commodity(){

    }

    //带参构造函数
    public Commodity(Date createDate,String describe,Date modifyDate,String name){
        this.createDate = createDate;
        this.describe = describe;
        this.modifyDate = modifyDate;
        this.name = name;
    }

    public Integer getId() {
        return id;
    }

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

    public Date getCreateDate() {
        return createDate;
    }

    public void setCreateDate(Date createDate) {
        this.createDate = createDate;
    }

    public String getDescribe() {
        return describe;
    }

    public void setDescribe(String describe) {
        this.describe = describe;
    }

    public Date getModifyDate() {
        return modifyDate;
    }

    public void setModifyDate(Date modifyDate) {
        this.modifyDate = modifyDate;
    }

    public String getName() {
        return name;
    }

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

    @Override
    public String toString() {
        return "Commodity [id=" + id + ", createDate=" + createDate + ", describe=" + describe + ", modifyDate="
                + modifyDate + ", name=" + name + "]";
    }

}

hibernate.cfg.xml:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <!-- 数据库连接四项driverclass,url,username,password -->
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/qsx_shop?characterEncoding=UTF-8</property>
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.connection.password">root</property>

        <!-- Hibernate方言，Hibernateh会根据配置的方言产生对应的sql语句 -->
        <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>

        <!-- 是否显示sql -->
        <property name="hibernate.show_sql">true</property>

        <!-- 是否格式化sql -->
        <property name="hibernate.format_sql">true</property>

        <!-- 配置数据实体类 -->
        <mapping class="online.shixun.model.Commodity" />
    </session-factory>
</hibernate-configuration>

DAO:

package online.shixun.test;

//import java.sql.Date;
import java.util.Date;
import java.text.ParseException;
import java.text.SimpleDateFormat;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistry;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;

import online.shixun.model.Commodity;

public class HibernateDemo {

    public static void main(String[] args) throws ParseException {
        //获取配置文件
        Configuration configuration = new Configuration().configure();
        //注册服务对象
        StandardServiceRegistryBuilder serviceRegistryBuilder = new StandardServiceRegistryBuilder();
        StandardServiceRegistry serviceRegistry = serviceRegistryBuilder.applySettings(configuration.getProperties()).build();
        //获取SessionFactory
        SessionFactory sessionFactory = configuration.buildSessionFactory(serviceRegistry);
        //获取session
        Session session = sessionFactory.openSession();
        //开启事务
        session.beginTransaction();
        //************开始操作*************//
        //1. 利用 get 方法获取 id 为 1 的用户数据
        Commodity getCommodity = (Commodity) session.get(Commodity.class, 1);
        System.out.println("创建日期:" + getCommodity.getCreateDate() + "描述:" + getCommodity.getDescribe() + "修改日期:" + getCommodity.getModifyDate() + "名称:" + getCommodity.getName());

//        Date date = new Date(0);
        String stringdate = "2019-05-07";
        Date date =  new SimpleDateFormat("YYYY-MM-DD").parse(stringdate);

        //2.增加商品
//        Commodity newCommodity = new Commodity(date,"电器1",date,"电饭锅2");
//        session.save(newCommodity);

        //3.删
//        Commodity getCommodity1 = (Commodity) session.load(Commodity.class, 2);
//        session.delete(getCommodity1);
//        session.getTransaction().commit();

        //4.改
//        Commodity getCommodity2 = (Commodity) session.get(Commodity.class, 1);
//        getCommodity2.setName("洗脸盆");
//        session.update(getCommodity2);
//        session.getTransaction().commit();
        //************结束操作*************//

        //提交事务
        session.getTransaction();
        //关闭session
        session.close();
        //关闭SessionFactory
        sessionFactory.close();
    }
}

Hibernate 配置文件有以下两种加载方式，如下：

//利用以下语句加载默认的 Hibernate 配置文件（名称：hibernate.cfg.xml）

Configuration configuration = new Configuration().configure();
//如果要自定义 Hibernate 配置文件名称，需要利用以下语句进行配置文件加载

Configuration configuration = new Configuration().configure("my-hibernate.cfg.xml");