hibernate oracle blob資料類型的處理

hibernate對blob的儲存和讀取比較特殊，不能像平常處理資料那樣進行操作，下面是hibernate中對oracle blob類型的處理的例子：

oracle資料庫建表語句

create table stu
(
   id number(2),
   name varchar2(16),
   filename varchar2(64),
   filedata BLOB,
   primary key(id)
);

Stu.java檔案

public class Stu implements java.io.Serializable {

 // Fields

 private Byte id;
 private String name;
 private String filename;
 private byte[]  filedata;  //此處理將其屬性類型設為byte[]

 // Constructors

 /** default constructor */
 public Stu() {
 }

剩餘部分略去.....

Stu.hbm.xml檔案如下：

<hibernate-mapping>
    <class name="com.aoyou.mapping.Stu" table="STU" schema="LIXIN03080">
        <id name="id" type="java.lang.Byte">
            <column name="ID" precision="2" scale="0" />
            <generator class="assigned" />
        </id>
        <property name="name" type="java.lang.String">
            <column name="NAME" length="16" />
        </property>
        <property name="filename" type="java.lang.String">
            <column name="FILENAME" length="64" />
        </property>

<hibernate-mapping>
    <class name="com.aoyou.mapping.Stu" table="STU" schema="LIXIN03080">
        <id name="id" type="java.lang.Byte">
            <column name="ID" precision="2" scale="0" />
            <generator class="assigned" />
        </id>
        <property name="name" type="java.lang.String">
            <column name="NAME" length="16" />
        </property>
        <property name="filename" type="java.lang.String">
            <column name="FILENAME" length="64" />
        </property>
        <!-- 注意下面filedata的type為binary -->
        <property name="filedata" type="binary">
            <column name="FILEDATA" />
        </property>
    </class>
</hibernate-mapping>
        <property name="filedata" type="binary">
            <column name="FILEDATA" />
        </property>
    </class>
</hibernate-mapping>

在main方法中測試：

儲存資料到資料庫:

public static void main(String[] args) throws IOException{
         Session session = new Configuration().configure().buildSessionFactory().openSession();
        Transaction t = session.beginTransaction();
  
        File file = new File("D:\\購物網站\\二期\\資料庫設計.txt");
       BufferedReader br = new BufferedReader(new FileReader(file));
  
  
       Stu stu = new Stu();
       stu.setId(2);
       stu.setName("mary");
       stu.setFilename("資料清單");
  
       String content = "";
      String temp = "";
      while((temp = br.readLine()) != null){
            content += temp;
       }
       br.close();
       stu.setFiledata(content.getBytes());
       session.save(stu);
  
       t.commit();
 }

讀取資料庫資料：

public static void main(String[] args) throws IOException{
           Session session = new Configuration().configure().buildSessionFactory().openSession();
           Transaction t = session.beginTransaction();
  
           String hql = " from Stu  ";
           Query query = session.createQuery(hql);
           List list = query.list();
           if(list != null){
                   Stu stu = (Stu)list.get(0);
                  System.out.println(stu.getId());
                  System.out.println(stu.getName());
                  System.out.println(stu.getFilename());
                  byte[] b = stu.getFiledata();
                 System.out.print(new   String(b,   0,   b.length));
           }
  
       t.commit();
 }