Hibernate 使用注释书写配置文件

Hibernate 使用注释

Hibernate使用注释有个好处就是我们不需要建立.hbm.xml文件，直接在实体类中添加注解就可以完成往数据库中进行数据操作

配置文件：hibernate.cfg.xml

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-configuration PUBLIC

    "-//Hibernate/Hibernate Configuration DTD//EN"

    "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<hibernate-configuration>

    <session-factory>

        <!-- Database connection settings -->

      <property name="connection.driver_class">com.mysql.jdbc.Driver</property>

      <property name="connection.url">jdbc:mysql://localhost:3306/student?serverTimezone=UTC</property>

      <property name="connection.username">root</property>

      <property name="connection.password">123456</property>

      <!-- JDBC connection pool (use the built-in) -->

      <!-- <property name="connection.pool_size">1</property> -->

      <!-- SQL dialect 方言 MySQLDialect不同数据库不一样-->

      <property name="dialect">org.hibernate.dialect.MySQLDialect</property>

      <!-- Enable Hibernate's automatic session context management -->

      <!-- <property name="current_session_context_class">thread</property> -->

      <!-- Disable the second-level cache -->

      <property name="cache.provider_class">org.hibernate.cache.internal.NoCacheProvider</property>

      <!-- Echo all executed SQL to stdout  生产的sql打印出来-->

      <property name="show_sql">true</property>

      <!-- <mapping resource="com/xxc/model/Student.hbm.xml"></mapping> -->

      <mapping class="com.xxc.model.Teacher"></mapping>

    </session-factory>

</hibernate-configuration>

实体类Teacher.java

package com.xxc.model;

import javax.persistence.Entity;

import javax.persistence.Id;

import javax.persistence.Table;

@Entity

@Table(name="teacher")

public class Teacher {

    private int id;

    private String name;

    private String title;

    @Id

    public int getId() {

        return id;

    }

    public void setId(int id) {

        this.id = id;

    }

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }

    public String getTitle() {

        return title;

    }

    public void setTitle(String title) {

        this.title = title;

    }

}

操作类TeacherTest.java

在这里，我们使用StandardServiceRegistryBuilder类和MetadataSources类从持久化类获取映射的信息。

package hibernateTest;

import org.hibernate.Session;

import org.hibernate.SessionFactory;

import org.hibernate.boot.MetadataSources;

import org.hibernate.boot.registry.StandardServiceRegistry;

import org.hibernate.boot.registry.StandardServiceRegistryBuilder;

import com.xxc.model.Teacher;

public class TeacherTest {

    public static void main(String[] args) {

        Teacher t = new Teacher();

        t.setId(1);

        t.setName("xxc");

        t.setTitle("高级");

        final StandardServiceRegistry registry = new StandardServiceRegistryBuilder().configure("hibernate.cfg.xml").build();

        SessionFactory sf = new MetadataSources(registry).buildMetadata().buildSessionFactory();

        Session session = sf.openSession();

        //开始事务

        session.beginTransaction();

        session.save(t);

        //结束事务

        session.getTransaction().commit();

        session.close();

        sf.close();

    }

}