hibernate3學習筆記(十三)｜Dynamic Model

在構造系統原型階段，由於需求尚未確定，程序中的POJO會在開發過程中存在相當大的變動，於是在Hibernate3中引入了動態模型的概念。如此不需要事先實際定義POJO。

數據庫DDL如下：

1.CREATE TABLE user (
2.    id INT(11) NOT NULL auto_increment PRIMARY KEY,
3.    name VARCHAR(100) NOT NULL default '',
4.    age INT
5.);

User.hbm.xml配置文件中設定entity-name屬性(屬性值為查找的唯一標示符，不可重復)。

1.<?xml version="1.0" encoding="UTF-8"?>
2.
3.<!DOCTYPE hibernate-mapping PUBLIC
4.    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
5.    "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
6.
7.<hibernate-mapping>
8.
9.    <class entity-name="com.hb3.pack_06.model.DynamicUserModel" table="user">
10.
11.        <id name="id" column="id" type="java.lang.Integer">
12.            <generator class="native"/>
13.        </id>
14.
15.        <property name="name"
16.                  column="name"
17.                  type="java.lang.String"/>
18.
19.        <property name="age"
20.                  column="age"
21.                  type="java.lang.Integer"/>
22.    </class>
23.
24.</hibernate-mapping>

修改hibernate.cfg.xml配置文件：

......
<mapping resource="com/hb3/pack_06/model/User.hbm.xml" />
......

測試代碼如下：

1.package com.hb3.pack_06;
2.
3.import java.util.HashMap;
4.import java.util.Map;
5.
6.import org.hibernate.Session;
7.import org.hibernate.SessionFactory;
8.import org.hibernate.Transaction;
9.import org.hibernate.cfg.Configuration;
10.
11.public class BusinessService {
12.
13.    public static void main(String[] args) {
14.
15.        Configuration config = new Configuration().configure();
16.        SessionFactory sessionFactory = config.buildSessionFactory();
17.        Session session = sessionFactory.openSession();
18.
19.        Map<String, Object> userMap = new HashMap<String, Object>();
20.        userMap.put("name", "shenbin");
21.        userMap.put("age", new Integer(28));
22.
23.        Transaction tx = session.beginTransaction();
24.        session.save("com.hb3.pack_06.model.DynamicUserModel", userMap);
25.        tx.commit();
26.
27.        session.close();
28.        session = sessionFactory.openSession();
29.
30.        userMap = (Map) session.load("com.hb3.pack_06.model.DynamicUserModel", new Integer(1));
31.        System.out.println(userMap.get("name"));
32.        System.out.println(userMap.get("age"));
33.
34.        session.close();
35.        sessionFactory.close();
36.    }
37.}