程式師世界 >> 編程語言 >> JAVA編程 >> 關於JAVA >> hibernate3學習筆記(十四)｜Blob、Clob

hibernate3學習筆記(十四)｜Blob、Clob

編輯：關於JAVA

在Hibernate中，可以直接對Blob、Clob作映射。

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.    photo BLOB,
6.    resume TEXT
7.);

注意：由於BLOB字段大小不可預計，有時需要增大BLOB字段的大小，可在數據庫中改用MEDIUMBLOB甚至LONGBLOB。

User.java

1.package com.hb3.pack_07.model;
2.
3.import java.sql.Blob;
4.import java.sql.Clob;
5.
6.public class User {
7.
8.    private Integer id;
9.    private String name;
10.    private Integer age;
11.    private Blob photo;
12.    private Clob resume;
13.
14.    public User() {
15.    }
16.
17.    public Integer getId() {
18.        return id;
19.    }
20.    public void setId(Integer id) {
21.        this.id = id;
22.    }
23.    public String getName() {
24.        return name;
25.    }
26.    public void setName(String name) {
27.        this.name = name;
28.    }
29.    public Integer getAge() {
30.        return age;
31.    }
32.    public void setAge(Integer age) {
33.        this.age = age;
34.    }
35.    public Blob getPhoto() {
36.        return photo;
37.    }
38.    public void setPhoto(Blob photo) {
39.        this.photo = photo;
40.    }
41.    public Clob getResume() {
42.        return resume;
43.    }
44.    public void setResume(Clob resume) {
45.        this.resume = resume;
46.    }
47.}

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_07.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.        <property name="photo" column="photo" type="java.sql.Blob"/>
20.
21.        <property name="resume" column="resume" type="java.sql.Clob"/>
22.
23.    </class>
24.
25.</hibernate-mapping>

修改hibernate.cfg.xml文件如下：

...... <mapping resource="com/hb3/pack_07/model/User.hbm.xml" /> ......

測試代碼如下：

1.package com.hb3.pack_07;
2.
3.import java.io.FileInputStream;
4.import java.io.FileOutputStream;
5.import java.io.IOException;
6.import java.io.InputStream;
7.import java.sql.Blob;
8.import java.sql.Clob;
9.import java.sql.SQLException;
10.
11.import org.hibernate.Hibernate;
12.import org.hibernate.Session;
13.import org.hibernate.SessionFactory;
14.import org.hibernate.Transaction;
15.import org.hibernate.cfg.Configuration;
16.
17.import com.hb3.pack_07.model.User;
18.
19.public class BusinessService {
20.
21.    public static void main(String[] args) throws IOException, SQLException {
22.
23.        Configuration config = new Configuration().configure();
24.        SessionFactory sessionFactory = config.buildSessionFactory();
25.        Session session = sessionFactory.openSession();
26.
27.        FileInputStream fileInputStream = new FileInputStream("c:\\sunset.jpg");
28.        Blob photo = Hibernate.createBlob(fileInputStream);
29.        Clob resume = Hibernate.createClob("Bla....Bla....resume text!!");
30.
31.        User user = new User();
32.        user.setName("shenbin");
33.        user.setAge(new Integer(28));
34.        user.setPhoto(photo);
35.        user.setResume(resume);
36.
37.        Transaction tx = session.beginTransaction();
38.        session.save(user);
39.        tx.commit();
40.
41.        session.close();
42.        session = sessionFactory.openSession();
43.
44.        user = (User) session.load(User.class, new Integer(1));
45.        System.out.print(user.getAge() + "\t" +
46.                         user.getName() + "\t");
47.        String str_resume = user.getResume().getSubString(1, (int) user.getResume().length());
48.        System.out.println(str_resume);
49.        InputStream inputStream = user.getPhoto().getBinaryStream();
50.        FileOutputStream fileOutputStream = new FileOutputStream("c:\\sunset_save.jpg");
51.        byte[] buf = new byte[1];
52.        int len = 0;
53.        while((len = inputStream.read(buf)) != -1) {
54.            fileOutputStream.write(buf, 0, len);
55.        }
56.        inputStream.close();
57.        fileOutputStream.close();
58.        System.out.println("save photo to c:\\sunset_save.jpg");
59.
60.        session.close();
61.        sessionFactory.close();
62.    }
63.}