Insert and display images in Oracle (BLOB type)

Insert and display images in Oracle (BLOB type)
Blob type for storing images in oracle

First, create a database:

-- Connect to the Administrator
Conn sys/tbsoft as sysdba;

-- Authorize scott user

Grant create any directory to scott;

-- Return to scott user

Conn scott/tiger;

-- Create a table for storing images
Create table IMAGE_LOB (T_ID VARCHAR2 (5) not null, T_IMAGE blob not null );

-- Create a directory for storing images
Create or replace directory images as 'C: \ picture ';

-- Create a folder named picture in c :.

Create or replace procedure IMG_INSERT (TID VARCHAR2, FILENAME VARCHAR2)
F_LOB BFILE; -- file type
B _LOB BLOB;
BEGIN
INSERT INTO IMAGE_LOB (T_ID, T_IMAGE)
VALUES (TID, EMPTY_BLOB () RETURN T_IMAGE INTO B _LOB;
-- Insert an empty blob.
F_LOB: = BFILENAME ('images', FILENAME );
-- Get files in the specified directory
DBMS_LOB.FILEOPEN (F_LOB, DBMS_LOB.FILE_READONLY );
-- Open a file in read-only mode
DBMS_LOB.LOADFROMFILE (B _LOB, F_LOB, DBMS_LOB.GETLENGTH (F_LOB ));
-- Transfer object
DBMS_LOB.FILECLOSE (F_LOB );
-- Close the original file
COMMIT;
END;
/

-- Put an image 1.gif under C: \ picture.

-- Save the image to a table
Call img_insert('1', '1.gif ');

Create a web project to connect to the database and create a BlobDAO class to retrieve blob images in the table.

Java code collection code

Public class BlobDAO {

Private static final BlobDAO instance = new BlobDAO ();

Private Connection conn = null;

Private BlobDAO (){

}

Public static BlobDAO getInstance (){
Return instance;
}

Private void initConn (){
Conn = DBAccess. getInstance (). getConn ();
}


Public byte [] getImage (String imgname ){
BufferedInputStream ins; // gets the blob io stream
Byte [] bt = null;

InitConn ();
Blob bo = null;
PreparedStatement ps = null;
ResultSet rs = null;
String SQL = "select T_IMAGE from IMAGE_LOB where t_id =? ";
Try {
Ps = conn. prepareStatement (SQL );
Ps. setString (1, imgname );
Rs = ps.exe cuteQuery ();
If (rs. next ()){
Bo = rs. getBlob ("T_IMAGE ");

Try {
Ins = new BufferedInputStream (bo. getBinaryStream ());
Int bufferSize = (int) bo. length (); // obtain the BLOB length.
Bt = new byte [bufferSize];
Try {
Ins. read (bt, 0, bufferSize );
} Catch (IOException e ){
// TODO Auto-generated catch block
E. printStackTrace ();
}
// Create a byte Cache
} Catch (SQLException e ){
// TODO Auto-generated catch block
E. printStackTrace ();
}

}
} Catch (SQLException e ){
// TODO Auto-generated catch block
E. printStackTrace ();
} Finally {
Try {
Rs. close ();
Ps. close ();
Conn. close ();
} Catch (SQLException e ){
// TODO Auto-generated catch block
E. printStackTrace ();
}
}

Return bt;
}
}

 

Call the getImage () method in the action and display the image on the page.

Java code collection code

Public ActionForward execute (ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response ){
// TODO Auto-generated method stub

BlobDAO blobDAO = BlobDAO. getInstance ();

Byte [] bs = blobDAO. getImage ("1 ");

Try {

Response. getOutputStream (). write (bs );

} Catch (IOException e ){
// TODO Auto-generated catch block
E. printStackTrace ();
}

Return null;
}

Add images to the database

Put the image in drive c: \ 4.gif

Java code collection code

Public void savaImg (String imgId ){
// Upload the id of the image stored in the database
InitConn ();
Statement st = null;
BLOB blob = null; // image type
OutputStream outputStream = null; // output stream
File file = null; // File
InputStream inputStream = null; // input stream
ResultSet rs = null;
Try {
Conn. setAutoCommit (false); // The transaction is operated by the programmer.
St = conn. createStatement ();
St.exe cuteQuery ("insert into IMAGE_LOB values ('" + imgId + "', empty_blob ())");
Rs = st.exe cuteQuery ("select T_IMAGE from IMAGE_LOB where t_id = '" + imgId + "' for update ");
If (rs. next ()){
Blob = (BLOB) rs. getBlob (1 );
OutputStream = blob. getBinaryOutputStream ();
File = new File ("c: \ 4.gif ");
InputStream = new FileInputStream (file );
Byte [] B = new byte [blob. getBufferSize ()];
Int len = 0;
While (len = inputStream. read (B ))! =-1 ){
System. out. println (len );
OutputStream. write (B, 0, len );
}
}

} Catch (SQLException e ){
// TODO Auto-generated catch block
E. printStackTrace ();
} Catch (FileNotFoundException e ){
// TODO Auto-generated catch block
E. printStackTrace ();
} Catch (IOException e ){
// TODO Auto-generated catch block
E. printStackTrace ();
} Finally {
Try {
InputStream. close ();
OutputStream. flush ();
OutputStream. close ();
Rs. close ();
St. close ();
Conn. commit ();
Conn. close ();
} Catch (IOException e ){
// TODO Auto-generated catch block
E. printStackTrace ();
} Catch (SQLException e ){
// TODO Auto-generated catch block
E. printStackTrace ();
}

}
}

 

Operation completed!

Author "669098238"