hibernate存储blob

① hibernate如何保存blob数据

首先你得搞清楚一点BLOB是二进制大对象，是ORACLE的数据类型，它对应到java中有两种方式：

byte[] 和java.sql.Blob(先搞清楚这重点哦)

我给你直接复制重点代码，希望可以帮到你

1 数据库中定义成BLOB类型，这个你自己定义吧（表名叫bigobject），~~~~~不过给你截个图吧

2 综上，把oracle数据库中的BLOB映射到java中有两种情况的，即java.sql.Blob和byte[]，下面先说byte[]的映射

++++++++++++++++++++++++Bigobject.hbm.xml映射文件+++++++++++++++++++++++

<hibernate-mapping>

<class name="entity.Bigobject" table="BIGOBJECT" >

<id name="id" type="java.lang.Integer">

<column name="ID" precision="6" scale="0" />

<generator class="native" />

</id>

<property name="tclob" type="java.lang.String">

<column name="TCLOB" />

</property>

<property name="tblob" type="byte[]"> //！！！！！注意，这里是byte[]

<column name="TBLOB" />

</property>

</class>

</hibernate-mapping>

++++++++++++++++++++以下是bigobject实体类（用hibernate映射的）+++++++++++

public class Bigobject implements java.io.Serializable {

// Fields

private Integer id;

private String tclob;

private byte[] tblob; //！！！！！注意，这里是byte[]

// Constructors

/** default constructor */

public Bigobject() {

}

/** full constructor */

public Bigobject(String tclob, byte[] tblob) {

this.tclob = tclob;

this.tblob = tblob;

}

御谨 // Property accessors

public Integer getId() {

return this.id;

}

public void setId(Integer id) {

镇册基 this.id = id;

}

public String getTclob() {

return this.tclob;

}

public void setTclob(String tclob) {

this.tclob = tclob;

}

public byte[] getTblob() {

return this.tblob;

}

public void setTblob(byte[] tblob) {

this.tblob = tblob;

}

========================控制台测试代码（读取图片到数据库，

再从数据库读取图片到特定路径下）=======================================

/**

* 按大对象数据类型BLOB的byte[]类型

* CLOB的java.lang.String

* 映射 并插入数据

* @author Administrator

*

*/

public class Test {

Session session=null;

Transaction tx=null;

/**

* 持久化数据，读取本地图片到数据库

*/

public void get1(){

姿态 try {

session=HibernateSessionFactory.getSession();

//前提是文件必须放在src路径下，读取的是当前项目的根目录

// InputStream input=this.getClass().getResourceAsStream("/file.txt");

//加载任意路径下的图片、大文件、视屏等(括号里的参数图片是绝对路径)

InputStream input=new FileInputStream("G:/在线拍卖/page/images/gou1.jpg");

tx=session.beginTransaction();

byte[] byteArray=new byte[input.available()];

input.read(byteArray);

input.close();

Bigobject b=new Bigobject();

b.setId(1);

b.setTblob(byteArray);

b.setTclob("一条狗");

session.save(b);

tx.commit();

} catch (HibernateException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

/**

* 从数据库bigObject表中按主键读取一条数据

* @throws IOException

*/

public void get2() throws IOException{

session=HibernateSessionFactory.getSession();

Bigobject b=(Bigobject)session.get(Bigobject.class, 1);

System.out.println("文本内容是："+b.getTclob());

//吧字节数组数据通过字节流，输出到当前工程根目录下2.jpg中

if(b.getTblob()!=null){

FileOutputStream out=new FileOutputStream("dog1.jpg");

out.write(b.getTblob());

out.close();

}

}

public static void main(String[] args) throws IOException {

test6 t=new test6();

t.get1();

t.get2();

}

===================hibernate.cfg.xml的代码页给你贴一下吧，不过这都是自动生成的，你自己动手生成吧，一下是我自己的，想用的话得改参数的=======================

<?xml version='1.0' encoding='UTF-8'?>

<!DOCTYPE hibernate-configuration PUBLIC

"-//Hibernate/Hibernate Configuration DTD 3.0//EN"

"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<!-- Generated by MyEclipse Hibernate Tools. -->

<hibernate-configuration>

<session-factory>

<property name="dialect">

org.hibernate.dialect.Oracle9Dialect

</property>

<property name="connection.url">

jdbc:oracle:thin:@localhost:1521:accp7 //!!!数据库名称

</property>

<property name="connection.username">scott</property>//!!!!!用户名

<property name="connection.password">accp</property>//!!!!!!密码

<property name="connection.driver_class">

oracle.jdbc.OracleDriver

</property>

<property name="myeclipse.connection.profile">scott</property>//!!!!!数据库实例名

<mapping resource="entity/Bigobject.hbm.xml" />

</session-factory>

</hibernate-configuration>

3 上面介绍了BLOB的byte[]存储，下面介绍另一种方式java.lang.Blob方式，还是直接粘贴代码

++++++++++++++++++++数据库还是上面图片上的，保持不变++++++++++++++++++++++

====================Bigobject.hbm.xml映射文件======================

<hibernate-mapping>

<class name="bean.Bigobject" table="BIGOBJECT">

<id name="id" type="java.lang.Integer">

<column name="ID" precision="6" scale="0" />

<generator class="native" />

</id>

<property name="tclob" type="java.sql.Clob">//这里用的是Clob的另一种方式，有疑问再问

<column name="TCLOB" />

</property>

<property name="tblob" type="java.sql.Blob">//！！！！！注意，这里是java.sql.Blob

<column name="TBLOB" />

</property>

</class>

</hibernate-mapping>

========================以下是bigobject实体类=======================

import java.sql.Blob;

import java.sql.Clob;

/**

* Bigobject entity. @author MyEclipse Persistence Tools

*/

public class Bigobject implements java.io.Serializable {

// Fields

private Integer id;

private Clob tclob;

private Blob tblob;

// Constructors

/** default constructor */

public Bigobject() {

}

/** full constructor */

public Bigobject(Clob tclob, Blob tblob) {

this.tclob = tclob;

this.tblob = tblob;

}

// Property accessors

public Integer getId() {

return this.id;

}

public void setId(Integer id) {

this.id = id;

}

public Clob getTclob() {

return this.tclob;

}

public void setTclob(Clob tclob) {

this.tclob = tclob;

}

public Blob getTblob() {

return this.tblob;

}

public void setTblob(Blob tblob) {

this.tblob = tblob;

}

}

==========================对应的控制台测试代码===========================

/**

* 讲字符串大对象声明为java.sql.Clob类型，二进制大对象声明为java.sql.Blob类型

* @author Administrator

*

*/

public class test7 {

Session session=null;

Transaction tx=null;

public void get1(){

try {

session=HibernateSessionFactory.getSession();

//前提是文件必须放在src路径下

InputStream input=this.getClass().getResourceAsStream("/upload.txt");

//加载任意路径下的图片、大文件、视屏等

// InputStream input=new FileInputStream("F:/1.jpg");

tx=session.beginTransaction();

byte[] byteArray=new byte[input.available()];

input.read(byteArray);

input.close();

Bigobject b=new Bigobject();

//依据二进制数据创建一个Blob对象 ！！！！！重点 务必看清楚

b.setTblob(Hibernate.createBlob(byteArray));

//依据字符串数据创建一个Clob对象 ！！！！！重点务必看清楚

b.setTclob(Hibernate.createClob("上传图片"));

session.save(b);

tx.commit();

} catch (HibernateException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

public void get2(){

session=HibernateSessionFactory.getSession();

Bigobject obj=(Bigobject)session.get(Bigobject.class, 131);

//把Clob对象通过字符流读入到内存，并输出

try {

if(obj.getTclob()!=null){

Reader read=obj.getTclob().getCharacterStream();

char[] chArray=new char[1];

StringBuilder sb=new StringBuilder();

while(read.read(chArray)!=-1){

sb.append(new String(chArray));

}

System.out.println(sb.toString().trim());

}

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

//把Blob对象通过字节流读输出，并保存到当前工程根目录下，取名为upload.txt

try {

if(obj.getTblob()!=null){

InputStream in=obj.getTblob().getBinaryStream();

FileOutputStream fos=new FileOutputStream("upload.txt");

int b=-1;

while((b=in.read())!=-1){

fos.write(b);

}

fos.close();

in.close();

}

} catch (FileNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

public static void main(String[] args) {

test7 t=new test7();

t.get1();

t.get2();

}

}

++++++++++++++++++++hibernate.cfg.xml同上++++++++++++++++++++++++++++

===================================================================

综上，Blob与Clob（字符串大对象）的写入读出的两种方法都有了（Clob的两种方法你自己捎带看看），都是完整代码，粘贴即可用，整理了两个多小时，希望对你有帮助！