hibernate3學習筆記(十二)｜Component

在MySQL中新建數據表User：

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.    email VARCHAR(100) NOT NULL
6.);

按照最基本的映射策略的話，應該把User類設計成：

1.package onlyfun.caterpillar;
2.
3.public class User {
4.    private Integer id;
5.    private String name;
6.    private int age;
7.    private String email;
8.
9.    ........
10.}

然而由於業務上的需要，要把email字段升格成MailAddress類，例如：

1.package com.hb3.pack_05.model;
2.
3.public class MailAddress {
4.
5.    private String email;
6.
7.    public MailAddress() {
8.    }
9.
10.    public String getEmail() {
11.        return email;
12.    }
13.
14.    public void setEmail(String email) {
15.        this.email = email;
16.    }
17.
18.    public void sendMail() {
19.        System.out.println("Send mail to " + email);
20.    }
21.}

User.java

1.package com.hb3.pack_05.model;
2.
3.public class User {
4.
5.    private Integer id;
6.    private String name;
7.    private Integer age;
8.    private MailAddress mailAddress;
9.
10.    public User() {
11.    }
12.
13.    public Integer getId() {
14.        return id;
15.    }
16.
17.    public void setId(Integer id) {
18.        this.id = id;
19.    }
20.
21.    public String getName() {
22.        return name;
23.    }
24.
25.    public void setName(String name) {
26.        this.name = name;
27.    }
28.
29.    public Integer getAge() {
30.        return age;
31.    }
32.
33.    public void setAge(Integer age) {
34.        this.age = age;
35.    }
36.
37.    public MailAddress getMailAddress() {
38.        return mailAddress;
39.    }
40.
41.    public void setMailAddress(MailAddress mailAddress) {
42.        this.mailAddress = mailAddress;
43.    }
44.}

User.hbm.xml文件：

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 name="com.hb3.pack_05.model.User" table="user">
10.
11.        <id name="id" column="id" type="java.lang.Integer">
12.            <generator class="native"/>
13.        </id>
14.
15.        <property name="name" column="name" type="java.lang.String"/>
16.
17.        <property name="age" column="age" type="java.lang.Integer"/>
18.
19.        <component name="mailAddress" class="com.hb3.pack_05.model.MailAddress">
20.            <property name="email"
21.                      column="email"
22.                      type="java.lang.String"
23.                      not-null="true"/>
24.        </component>
25.    </class>
26.</hibernate-mapping>

修改hibernate.cfg.xml文件：

......
<mapping resource="com/hb3/pack_05/model/User.hbm.xml" />
......

測試代碼如下：

1.package com.hb3.pack_05;
2.
3.import org.hibernate.Session;
4.import org.hibernate.SessionFactory;
5.import org.hibernate.Transaction;
6.import org.hibernate.cfg.Configuration;
7.
8.import com.hb3.pack_05.model.MailAddress;
9.import com.hb3.pack_05.model.User;
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.        MailAddress mailAddress = new MailAddress();
20.        mailAddress.setEmail("[email protected]");
21.
22.        User user = new User();
23.        user.setName("shenbin");
24.        user.setAge(new Integer(28));
25.        user.setMailAddress(mailAddress);
26.
27.        Transaction tx = session.beginTransaction();
28.        session.save(user);
29.        session.flush();
30.        tx.commit();
31.
32.        session.close();
33.
34.        session = sessionFactory.openSession();
35.
36.        user = (User) session.load(User.class, new Integer(1));
37.        System.out.println(user.getAge()  + "\t" +
38.                           user.getName() + "\t" +
39.                           user.getMailAddress().getEmail());
40.        user.getMailAddress().sendMail();
41.
42.
43.        session.close();
44.        sessionFactory.close();
45.    }
46.}