一、hibernate介绍
①、ORM框架/持久层框架 jdbc的一个框架;
②、object reference mapping 对象关系映射;
③、 通过管理对象来改变数据库中的数据 ,通过管理对象来操作数据库;
优势:跨数据库的无缝移植
二、在项目中添加hibernate支持
1 添加hibernate相关依赖
2 在resource目录下添加hibernate.cfg.xml(核心配置文件)
① 添加DTD支持
② 添加Hibernate的配置
(1) 数据库相关
(connection.username|connection.password|connection.url|connection.driver_class|dialect)
(2) 调试相关(show_sql|format_sql)
3 在开发阶段再创建实体类和实体映射文件(*.hbm.xml)
实体必须实现Serializable接口
小结:hibernate.cfg.xml(1)/*.hbm.xml(N) 实体映射文件一定要加到核心配置文件
三、测试maven的jar包
①、在pom.xml里面右键鼠标移到Run As会出现很多选项;
②、Maven clear:清除依赖;
③、Maven test:测试是否通过(控制台显示BUILD SUCCESS则表示通过);
四、Hibernate的CURD
1、新建一个maven项目
2、添加hibernate相关依赖
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.DHM</groupId>
<artifactId>hibernate</artifactId>
<packaging>war</packaging>
<version>0.0.1-SNAPSHOT</version>
<name>hibernate Maven Webapp</name>
<url>http://maven.apache.org</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
<junit.version>4.12</junit.version>
<servlet.version>4.0.0</servlet.version>
<hibernate.version>5.3.0.Final</hibernate.version>
<mysql.driver.version>8.0.19</mysql.driver.version>
</properties>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>${junit.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>4.0.1</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>${servlet.version}</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>${hibernate.version}</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>${mysql.driver.version}</version>
</dependency>
</dependencies>
<build>
<finalName>hibernate</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.7.0</version>
<configuration>
<source>${maven.compiler.source}</source>
<target>${maven.compiler.target}</target>
<encoding>${project.build.sourceEncoding}</encoding>
</configuration>
</plugin>
</plugins>
</build>
</project>
3、在resource目录下添加hibernate.cfg.xml(核心配置文件)
① 引入hibernate-configuration-3.0.dtd约束
name:类的全限定名
table:类的对应表
id标签:
name:类属性 type:类属性对应的java类型
column:数据库列段
priperty标签:
name:类属性 type:类属性对应的java类型
column:数据库列段
<?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-mapping>
<!--
name:类的全限定名
table:类的对应表
id标签:
name:类属性 type:类属性对应的java类型
column:数据库列段
priperty标签:
name:类属性 type:类属性对应的java类型
column:数据库列段
-->
<class name="com.dhm.entity.User" table="t_hibernate_user">
<id name="id" type="java.lang.Integer" column="id">
<generator class="assigned" />
</id>
<property name="userName" type="java.lang.String" column="user_name">
</property>
<property name="userPwd" type="java.lang.String" column="user_pwd">
</property>
<property name="realName" type="java.lang.String" column="real_name">
</property>
<property name="sex" type="java.lang.String" column="sex">
</property>
<property name="birthday" type="java.sql.Date" column="birthday">
</property>
<property insert="false" update="false" name="createDatetime"
type="java.sql.Timestamp" column="create_datetime">
</property>
<property name="remark" type="java.lang.String" column="remark">
</property>
</class>
</hibernate-mapping>
②、映射文件
<!-- 配置映射文件 -->
<mapping resource="com/dhm/entity/User.hbm.xml" />
<?xml version="1.0" encoding="UTF-8"?>
<!-- 引入dtd约束 -->
<!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>
<!-- 1. 数据库相关5.7 -->
<!-- <property name="connection.username">root</property> -->
<!-- <property name="connection.password">123456</property> -->
<!-- <property name="connection.url">jdbc:mysql://47.100.191.44:3308/lx?useUnicode=true&characterEncoding=UTF-8</property> -->
<!-- <property name="connection.driver_class">com.mysql.jdbc.Driver</property> -->
<!-- 1. 数据库相关8.0 -->
<property name="connection.username">root</property>
<property name="connection.password">123456</property>
<property name="connection.url">jdbc:mysql://127.0.0.1:3306/mybatis_ssm?useUnicode=true&characterEncoding=utf8&serverTimezone=GMT&useSSL=true</property>
<property name="connection.driver_class">com.mysql.cj.jdbc.Driver</property>
<!-- org.hibernate.dialect.MySQLDialect方言 -->
<property name="dialect">org.hibernate.dialect.MySQLDialect</property>
<!-- <property name="dialect">org.hibernate.dialect.Oracle10gDialect</property> -->
<!-- 配置本地事务(No CurrentSessionContext configured!) -->
<property name="hibernate.current_session_context_class">thread</property>
<!-- 2. 调试相关 -->
<property name="show_sql">true</property>
<property name="format_sql">true</property>
<!-- 配置映射文件 -->
<mapping resource="com/dhm/entity/User.hbm.xml" />
<!-- 主键生成策略 -->
<!-- <mapping resource="com/zking/two/entity/Student.hbm.xml" /> -->
<!-- <mapping resource="com/zking/two/entity/Worker.hbm.xml" /> -->
<!-- 一对多 -->
<!-- <mapping resource="com/zking/four/entity/Order.hbm.xml" /> -->
<!-- <mapping resource="com/zking/four/entity/OrderItem.hbm.xml" /> -->
<!-- 一对多的自关联 -->
<!-- <mapping resource="com/zking/five/entity/TreeNode.hbm.xml" /> -->
<!-- 多对多 -->
<!-- <mapping resource="com/zking/five/entity/Category.hbm.xml" /> -->
<!-- <mapping resource="com/zking/five/entity/Book.hbm.xml" /> -->
</session-factory>
</hibernate-configuration>
4、CURD
流程:
1、对框架核心配置文件进行建模
2、获取sessionFactory工厂
3、获取session会话
4、开启事务(查询不需要事务)
5、session操作对象
6、提交事务(查询不需要事务)
7、关闭session
①查询
package com.dhm.test;
import java.util.List;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class QueryDemo {
public static void main(String[] args) {
/**
* 1、对框架核心配置文件进行建模
* 2、获取sessionFactory工厂
* 3、获取session会话
* 4、开启事务(查询不需要事务)
* 5、session操作对象
* 6、提交事务(查询不需要事务)
* 7、关闭session
*/
Configuration configure = new Configuration().configure("/hibernate.cfg.xml");
SessionFactory sessionFactory = configure.buildSessionFactory();
Session session = sessionFactory.openSession();
List list = session.createQuery("from User").list();
for (Object object : list) {
System.out.println(object);
}
session.close();
}
}
结果(控制台):
Hibernate:
select
user0_.id as id1_0_,
user0_.user_name as user_nam2_0_,
user0_.user_pwd as user_pwd3_0_,
user0_.real_name as real_nam4_0_,
user0_.sex as sex5_0_,
user0_.birthday as birthday6_0_,
user0_.create_datetime as create_d7_0_,
user0_.remark as remark8_0_
from
t_hibernate_user user0_
User [id=1, userName=rrr, userPwd=999, realName=null, sex=null, birthday=null, createDatetime=null, remark=null]
User [id=2, userName=ls, userPwd=123, realName=李四, sex=男, birthday=2000-11-10, createDatetime=2018-09-29 17:58:13.0, remark=xyz]
User [id=3, userName=zzz2, userPwd=123, realName=null, sex=null, birthday=2018-09-29, createDatetime=2018-09-29 18:07:20.0, remark=null]
User [id=4, userName=zzz2, userPwd=123, realName=null, sex=null, birthday=2018-10-06, createDatetime=2018-10-06 15:17:54.0, remark=null]
User [id=5, userName=bbbb, userPwd=123s, realName=null, sex=null, birthday=null, createDatetime=2018-10-17 00:12:53.0, remark=null]
User [id=6, userName=ttttt, userPwd=6666, realName=null, sex=null, birthday=null, createDatetime=2018-10-17 19:46:20.0, remark=null]
User [id=7, userName=吃吃吃, userPwd=mima, realName=null, sex=null, birthday=null, createDatetime=2018-10-17 23:01:55.0, remark=null]
User [id=9, userName=吃吃吃22, userPwd=mima, realName=null, sex=null, birthday=null, createDatetime=2018-10-17 23:08:45.0, remark=null]
User [id=11, userName=xxx, userPwd=123456, realName=xxx, sex=1, birthday=null, createDatetime=2018-11-17 17:47:03.0, remark=xxx]
User [id=12, userName=xxx, userPwd=123456, realName=xxx, sex=1, birthday=null, createDatetime=2018-11-17 17:48:17.0, remark=xxx]
User [id=13, userName=xxx, userPwd=123456, realName=xxx, sex=1, birthday=2018-11-17, createDatetime=2018-11-17 17:48:48.0, remark=xxx]
User [id=14, userName=精华, userPwd=123456, realName=金燕, sex=女, birthday=null, createDatetime=2018-11-18 17:24:38.0, remark=开小差]
主键生成器
generator元素:表示了一个主键生成器,它用来为持久化类实例生成唯一的标识 。
1、 程序员自己控制:assigned
2、数据库控制: identity(标识列/自动增长) sequence
3、 hibernate控制:increment uuid/uuid.hex
4、 其它:native
②增加
package com.dhm.test;
import java.sql.Date;
import java.sql.Timestamp;
import java.util.List;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import com.dhm.entity.User;
public class AddDemo {
public static void main(String[] args) {
/**
* 1、对框架核心配置文件进行建模
* 2、获取sessionFactory工厂
* 3、获取session会话
* 4、开启事务(查询不需要事务)
* 5、session操作对象
* 6、提交事务(查询不需要事务)
* 7、关闭session
*/
Configuration configure = new Configuration().configure("/hibernate.cfg.xml");
SessionFactory sessionFactory = configure.buildSessionFactory();
Session session = sessionFactory.openSession();
Transaction transaction = session.beginTransaction();
User user=new User();
user.setBirthday(new Date(System.currentTimeMillis()));
user.setCreateDatetime(new Timestamp(System.currentTimeMillis()));
user.setId(55);
user.setRealName("xxd");
user.setRemark("武侠剧");
user.setSex("男");
user.setUserName("四条眉毛");
user.setUserPwd("123456");
session.save(user);
transaction.commit();
session.close();
}
}
结果:
数据库新增一条
③修改
package com.dhm.test;
import java.util.List;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import com.dhm.entity.User;
public class EditDemo {
public static void main(String[] args) {
Configuration configure = new Configuration().configure("/hibernate.cfg.xml");
SessionFactory sessionFactory = configure.buildSessionFactory();
Session session = sessionFactory.openSession();
Transaction transaction = session.beginTransaction();
User user = session.get(User.class, 55);
user.setRealName("a带");
transaction.commit();
session.close();
}
}
结果:
控制台
Hibernate:
select
user0_.id as id1_0_0_,
user0_.user_name as user_nam2_0_0_,
user0_.user_pwd as user_pwd3_0_0_,
user0_.real_name as real_nam4_0_0_,
user0_.sex as sex5_0_0_,
user0_.birthday as birthday6_0_0_,
user0_.create_datetime as create_d7_0_0_,
user0_.remark as remark8_0_0_
from
t_hibernate_user user0_
where
user0_.id=?
Hibernate:
update
t_hibernate_user
set
user_name=?,
user_pwd=?,
real_name=?,
sex=?,
birthday=?,
remark=?
where
id=?
数据库
④、删除
package com.dhm.test;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import com.dhm.entity.User;
public class DelDemo {
public static void main(String[] args) {
Configuration configure = new Configuration().configure("/hibernate.cfg.xml");
SessionFactory sessionFactory = configure.buildSessionFactory();
Session session = sessionFactory.openSession();
Transaction transaction = session.beginTransaction();
User user = session.get(User.class, 55);
session.delete(user);
transaction.commit();
session.close();
}
}
控制台
Hibernate:
select
user0_.id as id1_0_0_,
user0_.user_name as user_nam2_0_0_,
user0_.user_pwd as user_pwd3_0_0_,
user0_.real_name as real_nam4_0_0_,
user0_.sex as sex5_0_0_,
user0_.birthday as birthday6_0_0_,
user0_.create_datetime as create_d7_0_0_,
user0_.remark as remark8_0_0_
from
t_hibernate_user user0_
where
user0_.id=?
Hibernate:
delete
from
t_hibernate_user
where
id=?