Use hibernate to read and write data of the Oracle blob/clob type

Environment: eclipse3.1 + hibernate2 + Oracle 10g
Note: In this example, eclipse3.1 is used to read and write blob/clob data in Oracle through a Java project.
1. Create a new table in the Oracle database named bigdata. The SQL statement is as follows:
Create Table bigdata (ID number not null, image blob, resume clob); // create a table
Alter table bigdata add (constraint bigdata_pk primary key (ID) using index); // modify the ID to the primary key:

2. Create a New Java project in eclipse named hibernatesample. You can import the JAR file to be imported in the project as needed.
Create a source folder SRC, create a new package under SRC, name it bigdataaccess, and create a class under the package named datamodel. java. The content is as follows:
Package bigdataaccess;

Import java. SQL. Blob;
Import java. SQL. clob;

Public class datamodel {
Long ID;

Blob image;

Clob resume;

Public long GETID (){
Return ID;
}

Public void setid (long ID ){
This. ID = ID;
}

Public blob getimage (){
Return image;
}

Public void setimage (BLOB image ){
This. Image = image;
}

Public clob getresume (){
Return resume;
}

Public void setresume (clob resume ){
This. Resume = resume;
}
}

2. Create a class named hibernateutil. Java under the bigdataaccess package to manage the session. The source code is as follows:
Package bigdataaccess;

Import net. SF. hibernate .*;
Import net. SF. hibernate. cfg. configuration;

Public class hibernateutil {
Private Static sessionfactory;

Public static final threadlocal session = new threadlocal ();
Static {
Try {
// Instantiate a sessionfactory object
// System. Out. println ("Create a sessionfactory through the static module ");
Sessionfactory = new configuration (). Configure ()
. Buildsessionfactory ();
} Catch (hibernateexception ex ){
Throw new runtimeexception ("configuration problem :"
+ Ex. getmessage (), Ex );
}
}
Public static session currentsession () throws hibernateexception {
Session S = (Session) Session. Get ();
// When the original session is empty or closed, create a new session.
If (S = NULL |! S. isopen ()){
S = sessionfactory. opensession ();
Session. set (s );
}
Return S;
}

Public static void closesession () throws hibernateexception {
Session S = (Session) Session. Get ();
If (s! = NULL ){
S. Close ();
}
}
}

2. Create the biging file bigdataaccess. HBM. xml under the bigdataaccess package. The content is as follows:
<? XML version = "1.0"?>
<! Doctype hibernate-mapping public
"-// Hibernate/hibernate mapping DTD 2.0 // en"
Http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd>

<Hibernate-mapping>
<Class name = "bigdataaccess. datamodel" table = "bigdata">
<ID name = "ID" type = "long" column = "ID">
<Generator class = "increment"/>
</ID>
<Property name = "image" type = "Java. SQL. Blob" column = "image"/>
<Property name = "resume" type = "Java. SQL. clob" column = "resume"/>
</Class>
</Hibernate-mapping>
3. Create a New hibernate configuration file under the src directory. The content of hibernate. cfg. XML is as follows:
<? XML version = '1. 0' encoding = 'utf-8'?>
<! Doctype hibernate-configuration public "-// hibernate/hibernate configuration DTD // en"
Http://hibernate.sourceforge.net/hibernate-configuration-2.0.dtd>

<Hibernate-configuration>
<Session-factory>
<Property name = "hibernate. Connection. driver_class"> oracle. JDBC. Driver. oracledriver </property>
<Property name = "hibernate. Connection. url"> JDBC: oracle: thin: @ localhost: 1521: orcl </property>
<Property name = "hibernate. Connection. username"> Work </property>
<Property name = "hibernate. Connection. Password"> caecaodb </property>
<Property name = "hibernate. show_ SQL"> true </property>
<Property name = "dialect"> net. SF. hibernate. dialect. oracledialect </property>
<! -- This sentence must be added. Otherwise, an error will be reported, because oracle JDBC does not allow stream operations to be performed in batches, so disable -->
<Property name = "hibernate. JDBC. batch_size"> 0 </property>
<Mapping Resource = "bigdataaccess/bigdataaccess. HBM. xml"/>
</Session-factory>
</Hibernate-configuration>
4. Create a class with the main () function under the bigdataaccess package and name it hibernatetest. java. The source code is as follows:
Package bigdataaccess;
// Note that the correct package must be imported

Public class hibernatetest {

Public hibernatetest () throws hibernateexception, sqlexception, ioexception {
Doit ();
}

Public static void main (string [] ARGs) throws hibernateexception,
Sqlexception, ioexception {
New hibernatetest ();

}

Public void doit () throws hibernateexception, sqlexception, ioexception {

// Blog, clob data read/write --------- write

/*
* The Oracle blob/clob field itself has a cursor (cursor ),
* JDBC uses a cursor to operate the Blob/clob field. Before the Blob/clob field is created,
* The cursor handle cannot be obtained. Therefore, you must first create an empty blob/clob field, then obtain the cursor from the empty blob/clob field, and then write the data to be saved.
*/
System. Out. println ("Write Data ");
Session session = hibernateutil. currentsession ();
Transaction Tx = session. begintransaction ();

Datamodel info = new datamodel ();
Info. setimage (hibernate. createblob (New byte [1]);
Info. setresume (hibernate. createclob (""); // The parameter here is a space
Session. Save (Info );
Session. Flush (); // force insert
// Use the refresh method to force hibernate to execute select for update
Session. Refresh (Info, lockmode. Upgrade );

// Write the actual content to the blog
Oracle. SQL. Blob blob = (Oracle. SQL. Blob) info. getimage ();
Fileinputstream imgis = new fileinputstream ("D: // image.jpg"); // put an image.jpg file under the D:/root directory.
Outputstream out = blob. getbinaryoutputstream ();
Byte [] Buf = new byte [1, 10240];
Int Len;
While (LEN = imgis. Read (BUF)> 0 ){
Out. Write (BUF, 0, Len );
}
Imgis. Close ();
Out. Close ();

// Write actual content to clob
Oracle. SQL. clob = (Oracle. SQL. clob) info. getresume ();
Writer writer = clob. getcharacteroutputstream ();
Writer. Write ("this is my resume ");
Writer. Close ();

Session. Save (Info );
TX. Commit ();
// Read the data written into the database
System. Out. println ("read data ");
Datamodel info1 = (datamodel) session
. Load (datamodel. Class, new long (1 ));
Clob resume = info1.getresume ();
System. Out. println ("resume ="
+ Resume. getsubstring (1, (INT) resume. Length ()));

Blob IMG = info1.getimage ();
Inputstream is = IMG. getbinarystream ();
Fileoutputstream Fos = new fileoutputstream ("D: // outimage.jpg"); // read to D:/outimage.jpg
Byte [] buf1 = new byte [10240];
Int len1;
While (len1 = is. Read (buf1 ))! =-1 ){
FOS. Write (buf1, 0, len1 );
}
FOS. Close ();
Is. Close ();
Session. Close ();
}

Right-click hibernatetest. Java and run it as a Java application. When you query the bigdata table, a new record is added. D:/has a file named outimage.jpg, indicating that it is successful.