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Hibernate基础入门

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  Hibernate是一个开放源代码的对象关系映射框架,它将POJO与数据库表之间建立映射关系。是全自动的ORM框架,可以自动生成SQL语句并自动执行。它对JDBC进行了非常轻量级的封装,使程序员可以随心所欲地以操作对象的编程思维操作数据库。

  ORM :对象关系模型。O指面向对象领域的JavaBean,R指关系数据库领域的Relational(数据库表结构),M指映射Mapping(XML的配置文件)。

       技术分析之Hibernate的快速入门:

    第一步:下载Hibernate5的运行环境**

      1. 下载相应的jar包等
               https://sourceforge.net/projects/hibernate/files/hibernate-orm/5.0.7.Final/hibernate-release-5.0.7.Final.zip/download    
    
              2. 解压后对目录结构有一定的了解

    第二步:创建表结构

    Create database hibernate_day01;
              Use hibernate_day01;
              CREATE TABLE `cst_customer` (
          `cust_id` bigint(32) NOT NULL AUTO_INCREMENT COMMENT ‘客户编号(主键)‘,
          `cust_name` varchar(32) NOT NULL COMMENT ‘客户名称(公司名称)‘,
          `cust_user_id` bigint(32) DEFAULT NULL COMMENT ‘负责人id‘,
          `cust_create_id` bigint(32) DEFAULT NULL COMMENT ‘创建人id‘,
          `cust_source` varchar(32) DEFAULT NULL COMMENT ‘客户信息来源‘,
          `cust_industry` varchar(32) DEFAULT NULL COMMENT ‘客户所属行业‘,
          `cust_level` varchar(32) DEFAULT NULL COMMENT ‘客户级别‘,
          `cust_linkman` varchar(64) DEFAULT NULL COMMENT ‘联系人‘,
          `cust_phone` varchar(64) DEFAULT NULL COMMENT ‘固定电话‘,
          `cust_mobile` varchar(16) DEFAULT NULL COMMENT ‘移动电话‘,
          PRIMARY KEY (`cust_id`)
        ) ENGINE=InnoDB AUTO_INCREMENT=94 DEFAULT CHARSET=utf8;

    第三步:搭建Hibernate的开发环境

    1. 创建WEB工程,引入Hibernate开发所需要的jar包
        * MySQL的驱动jar包
        * Hibernate开发需要的jar包(资料/hibernate-release-5.0.7.Final/lib/required/所有jar包)
        * 日志jar包(资料/jar包/log4j/所有jar包)

    第四步:编写Java实体类

    1. Customer类的代码如下:
        public class Customer {
            private Long cust_id;
            private String cust_name;
            private Long cust_user_id;
            private Long cust_create_id;
            private String cust_source;
            private String cust_industry;
            private String cust_level;
            private String cust_linkman;
            private String cust_phone;
            private String cust_mobile;
            // 省略get和set方法
        }

   **第五步:创建类与表结构的映射**
    
    1. 在JavaBean所在的包下创建映射的配置文件
        * 默认的命名规则为:实体类名.hbm.xml
        * 在xml配置文件中引入约束(引入的是hibernate3.0的dtd约束,不要引入4的约束)
            <!DOCTYPE hibernate-mapping PUBLIC 
                "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
                "https://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
    
    2. 如果不能上网,编写配置文件是没有提示的,需要自己来配置
        * 先复制https://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd --> window --> preferences --> 搜索xml --> 选择xml catalog --> 点击add --> 现在URI --> 粘贴复制的地址 --> 选择location,选择本地的DTD的路径
    
    3. 编写映射的配置文件
        <?xml version="1.0" encoding="UTF-8"?>
        <!DOCTYPE hibernate-mapping PUBLIC 
            "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
            "https://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
        
        <hibernate-mapping>
            <class name="com.itheima.domain.Customer" table="cst_customer">
                <id name="cust_id" column="cust_id">
                    <generator class="native"/>
                </id>
                <property name="cust_name" column="cust_name"/>
                <property name="cust_user_id" column="cust_user_id"/>
                <property name="cust_create_id" column="cust_create_id"/>
                <property name="cust_source" column="cust_source"/>
                <property name="cust_industry" column="cust_industry"/>
                <property name="cust_level" column="cust_level"/>
                <property name="cust_linkman" column="cust_linkman"/>
                <property name="cust_phone" column="cust_phone"/>
                <property name="cust_mobile" column="cust_mobile"/>
            </class>
        </hibernate-mapping>
     

    **第六步:编写Hibernate核心的配置文件**
    
    1. 在src目录下,创建名称为hibernate.cfg.xml的配置文件
    2. 在XML中引入DTD约束
        <!DOCTYPE hibernate-configuration PUBLIC
            "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
            "https://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
    
    3. 打开:资料/hibernate-release-5.0.7.Final/project/etc/hibernate.properties,可以查看具体的配置信息    
        * 必须配置的4大参数                    
            #hibernate.connection.driver_class com.mysql.jdbc.Driver
            #hibernate.connection.url jdbc:mysql:///test
            #hibernate.connection.username gavin
            #hibernate.connection.password
        
        * 数据库的方言(必须配置的)
            #hibernate.dialect org.hibernate.dialect.MySQLDialect
        
        * 可选的配置
            #hibernate.show_sql true
            #hibernate.format_sql true
            #hibernate.hbm2ddl.auto update
        
        * 引入映射配置文件(一定要注意,要引入映射文件,框架需要加载映射文件)
            * <mapping resource="com/itheima/domain/Customer.hbm.xml"/>                
    
    4. 具体的配置如下
        <?xml version="1.0" encoding="UTF-8"?>
        <!DOCTYPE hibernate-configuration PUBLIC
            "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
            "https://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
        
        <hibernate-configuration>
            <session-factory>
                <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
                <property name="hibernate.connection.url">jdbc:mysql:///hibernate_day01</property>
                <property name="hibernate.connection.username">root</property>
                <property name="hibernate.connection.password">root</property>
                <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
                
                <mapping resource="com/itheima/domain/Customer.hbm.xml"/>
            </session-factory>
        </hibernate-configuration>

----------

**第七步:编写Hibernate入门代码**    

    1. 具体的代码如下
        /**
         * 测试保存客户
         */
        @Test
        public void testSave(){
            // 先加载配置文件
            Configuration config = new Configuration();
            // 默认加载src目录下的配置文件
            config.configure();
            // 创建SessionFactory对象
            SessionFactory factory = config.buildSessionFactory();
            // 创建session对象
            Session session = factory.openSession();
            // 开启事务
            Transaction tr = session.beginTransaction();
            // 编写保存代码
            Customer c = new Customer();
            // c.setCust_id(cust_id);    已经自动递增
            c.setCust_name("测试名称");
            c.setCust_mobile("110");
            // 保存客户
            session.save(c);
            // 提交事务
            tr.commit();
            // 释放资源
            session.close();
            factory.close();
        }
    

 

Hibernate基础入门

标签:加载   bean   ddl   data   创建web工程   source   private   avi   main   

原文:https://www.cnblogs.com/fengshine/p/10280865.html

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