Hibernate配置及初探

一个hibernate项目的搭建

• 创建一个maven项目
• 添加maven依赖，pom.xml文件配置如下:

<dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.11</version>
            <scope>test</scope>
        </dependency>
        <!-- 添加Hibernate依赖 -->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>3.6.10.Final</version>
        </dependency>

        <!-- 添加Log4J依赖 -->
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.16</version>
        </dependency>

        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-nop</artifactId>
            <version>1.6.4</version>
        </dependency>

        <!-- 添加javassist -->
        <dependency>
            <groupId>javassist</groupId>
            <artifactId>javassist</artifactId>
            <version>3.12.0.GA</version>
        </dependency>

        <!-- mysql数据库的驱动包 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.18</version>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-api</artifactId>
            <version>RELEASE</version>
            <scope>compile</scope>
        </dependency>
    </dependencies>

• 初始化sql语句，首先要先创建好名为user的数据库

CREATE TABLE User(
  id BIGINT(32) NOT NULL AUTO_INCREMENT COMMENT '用户信息',
  name VARCHAR(11) NOT NULL COMMENT '名称',
  birthday VARCHAR(32) NOT NULL COMMENT '生日',
  PRIMARY KEY (id)
)ENGINE=InnoDB AUTO_INCREMENT=94 DEFAULT CHARSET=utf8;

• 创建好数据库操作对象User，实现Serializable接口

package com.ryan;

import java.io.Serializable;

public class User implements Serializable {
    private Long id;
    private String name;
    private String birthday;

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

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

    public void setBirthday(String birthday) {
        this.birthday = birthday;
    }

    public String getName() {
        return name;
    }

    public Long getId() {
        return id;
    }

    public String getBirthday() {
        return birthday;
    }
}

• 在resources目录下创建User.hbm.xml文件，实际是实体类与数据库关系的映射(mapping)

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">

<hibernate-mapping package="com.ryan">
    <class name="User" table="user">
        <id name="id" column="id">
            <!-- 使用本地数据库的自动增长能力 -->
            <generator class="native"/>
        </id>
        <property name="name" column="name"></property>
        <property name="birthday" column="birthday"></property>
    </class>
</hibernate-mapping>

• 在resources目录下创建hibernate.cfg.xml配置文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <!-- 连接数据库配置信息 -->
        <property name="hibernate.connection.driver_class">com.mysql.cj.jdbc.Driver</property>
        <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/hibernate?serverTimezone=UTC</property>
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.connection.password">123456</property>
        <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
        <!-- 配置数据库的可选信息 -->
        <property name="show_sql">true</property> <!-- 是否显示hibernate生成的sql语句 -->
        <property name="format_sql">true</property> <!-- 是否规格化输出 -->
        <property name="hbm2ddl.auto">update</property> <!-- hibernate以何种方式生成DDL -->
        <!-- 配置映射文件的位置 -->
        <mapping resource="User.hbm.xml"/>
    </session-factory>
</hibernate-configuration>

• 下面就开始测试demo:

package test;

import com.ryan.User;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.junit.jupiter.api.Test;

public class HibernateDemo1 {

    @Test
    public void test1(){
        //读取配置内容
        Configuration cfg = new Configuration();
        cfg.configure();
        //创建SessionFactory, SessionFactory的主要作用就是创建Session
        SessionFactory factory = cfg.buildSessionFactory();
        User user = new User();
        user.setId(2L);
        user.setName("wwh");
        user.setBirthday("19980111");
        //创建Session
        Session session = factory.openSession();
        //开启事务
        Transaction transaction = session.beginTransaction();
        //保存操作
        session.save(user);
        //提交事务
        transaction.commit();
        //释放资源
        session.close();
        factory.close();
    }
}