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Hibernate简单使用

前言

使用IDEA+Maven进行搭建Hibernate5

步骤

导入

在pom.mxl中加入maven项目

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<dependencies>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-search-orm</artifactId>
<version>5.5.5.Final</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>6.0.5</version>
</dependency>
<dependencies>

创建配置文件

/src/main/resources/hibernate.cfg.xml中配置

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<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD//EN"
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<!--访问数据库的url地址,带参数防止编译错误-->
<property name="connection.url">jdbc:mysql://localhost:3306/test?serverTimezone=GMT&useUnicode=true&characterEncoding=utf8</property>
<property name="connection.driver_class">com.mysql.jdbc.Driver</property><!--数据库的JDBC驱动-->
<property name="connection.username">root</property><!--连接数据库的用户名-->
<property name="connection.password">root</property><!--连接数据库的用户密码-->
<property name="dialect">org.hibernate.dialect.MySQLDialect</property><!--指定使用mysql数据库的方言-->

<property name="show_sql">true</property><!--在控制台输出sql语句-->
<property name="format_sql">true</property><!--在控制台格式化sql语句-->
<property name="hbm2ddl.auto">create</property><!--生成表结构的策略-->
<mapping resource="students.hbm.xml"/>
<mapping class="com.ahao.javaeeDemo.Students"/>
</session-factory>
</hibernate-configuration>

创建实体

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//Students.java
public class Student{
private int sid;
private String sname;
//构造器、getter和setter
}
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<!--students.hbm.xml-->
<?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>
<class name="com.ahao.javaeeDemo.Students" table="students">
<id name="sid" type="int">
<column name="sid"/>
<generator class="increment"/>
</id>
<property name="sname" type="java.lang.String">
<column name="sname"/>
</property>
</class>
</hibernate-mapping>

编写测试代码

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public class MainTest {
private static ServiceRegistry serviceRegistry;
private static SessionFactory sessionFactory;
private static Session session;
private static Transaction transaction;
@BeforeClass
public static void initClass(){
//创建服务注册对象
serviceRegistry = new StandardServiceRegistryBuilder()
.configure("hibernate.cfg.xml").build();
//创建会话工厂对象
sessionFactory = new MetadataSources(serviceRegistry).buildMetadata().buildSessionFactory();
//创建会话对象
session = sessionFactory.openSession();
//开启事务
transaction = session.beginTransaction();
}

@Test
public void testSave(){
Students s = new Students();
s.setSname("zhangsan");
s.setBirthday(new java.sql.Date(System.currentTimeMillis()));
session.save(s);
}

@AfterClass
public static void destoryClass(){
//提交事务
transaction.commit();
//关闭会话
session.close();
//关闭会话工厂
sessionFactory.close();
}
}

操作

使用save()

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public class MainTest {
//省略初始化代码
@Test
public void testSave(){
Students s = new Students();
s.setSname("zhangsan");
s.setBirthday(new java.sql.Date(System.currentTimeMillis()));
session.save(s);
}
//省略销毁代码
}

使用update()

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public class MainTest {
//省略初始化代码
@Test
public void testUpdate(){
int sid = 1;
Students s = session.get(Students.class, sid);
s.setSname("Cat");
session.update(s);
// session.saveOrUpdate(s);
}
//省略销毁代码
}

使用delete()

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public class MainTest {
//省略初始化代码
@Test
public void testDelete(){
int sid = 1;
Students s = session.get(Students.class, sid);
session.delete(s);
}
//省略销毁代码
}

查询单个记录

使用get()load()

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public class MainTest {
//省略初始化代码
@Test
public void testRead(){
int sid = 1;
Students s1 = session.get(Students.class, sid);//发送sql语句,获取Students对象
System.out.println(s1.toString());//打印输出
Students s2 = session.load(Students.class, sid);//不发送sql语句,获取一个代理对象
System.out.println(s2.toString());//使用的时候才发送sql语句,获取Students对象
} //省略销毁代码
}
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