Display blob images of databases in java applications

Principle:
<1> Read blob to Blob Object from database. Blob blob = rs. getBlob (2 );
<2> pass blob to Stream.
<3> use the Stream parameter to create an Image object
<4> display the Image object.
Note: This is just an example. I do not consider other aspects. I hope you can have a detailed understanding of connecting to the database using java and getting objects.
SQL statements about databases
Create table photo (
Photo_no int (6) unsigned not null auto_increment,
Image blob,
Primary key ('photo _ no ')
)
In this example, two files are used:
DrawPanel. java is as follows:
Import java. awt .*;
Import java. SQL .*;
Import java. awt. image .*;
Import java. io .*;
Import javax. swing .*;

/**
* <P> Title: </p>
*
* <P> Description: vincentlaw@163.com </p>
*
* <P> Copyright: Copyright (c) 2005 </p>
*
* <P> Vincent </p>
*
* @ Author vincent
* @ Version 1.0
*/

Public class DrawPanel extends Panel {
Image im;
Insets insets;
Public DrawPanel (){
Im = Toolkit. getdefatooltoolkit (). getImage ("c: 1.jpg"); // default file
Try {
JbInit ();
} Catch (Exception ex ){
Ex. printStackTrace ();
}
}
Public void addpolicy (){
Super. addpolicy ();
Insets = getInsets ();
SetBounds (100,100,217 + insets. left, 321 + insets. top );
}
Public void paint (Graphics g ){
G. drawImage (im, insets. left, insets. top, this );
}
Private void jbInit () throws Exception {
}
Public void changeImage (String fileName)
{
Try {
// Class. forName ("oracle. jdbc. driver. OracleDriver ");
// Connection conn = DriverManager. getConnection ("jdbc: oracle: thin: @ 127.0.0.1: 1521: orcl2", "user", "password ");
Class. forName ("com. mysql. jdbc. Driver ");
Connection conn = DriverManager. getConnection ("jdbc: mysql: // localhost: 3306/job? User = root & password = 5672831 ");
Statement stmt = conn. createStatement ();
ResultSet rs = stmt.exe cuteQuery ("select photo_no, photo_image from photo ");
Rs. next ();
Blob blob = rs. getBlob (2 );
// Database connection
InputStream fin = blob. getBinaryStream ();
Im = javax. imageio. ImageIO. read (fin );
Rs. close ();
Stmt. close ();
Conn. close ();
}
Catch (Exception e)
{
E. printStackTrace ();
JOptionPane. showMessageDialog (null, "error, local file loading ");
Im = Toolkit. getdefatooltoolkit (). getImage (fileName );
}
This. repaint ();
}
}
ShowImage. java is as follows:

Import java. awt. BorderLayout;
Import java. awt .*;
Import javax. swing .*;
Import javax. swing. JToggleButton;
Import java. awt. event. ActionEvent;
Import java. awt. event. ActionListener;
/**
* <P> Title: </p>
*
* <P> Description: vincentlaw@163.com </p>
*
* <P> Copyright: Copyright (c) 2005 </p>
*
* <P> Vincent </p>
*
* @ Author vincent
* @ Version 1.0
*/
Public class ShowImage extends JFrame {
BorderLayout borderLayout1 = new BorderLayout ();
JToggleButton jToggleButton1 = new JToggleButton ();
DrawPanel = new DrawPanel ();

Public ShowImage (){
Try {
JbInit ();
} Catch (Exception exception ){
Exception. printStackTrace ();
}
}
Private void jbInit () throws Exception {
GetContentPane (). setLayout (borderLayout1 );
JToggleButton1.setText ("jToggleButton1 ");
JToggleButton1.addActionListener (new
Showimage_jtogglebutton?actionadapter (this ));
This. getContentPane (). add (jToggleButton1, java. awt. BorderLayout. NORTH );
This. getContentPane (). add (panel, java. awt. BorderLayout. CENTER );
}
Public void jtogglebutton?action=med (ActionEvent e ){
Panel. changeImage ("E: photohoto1281.jpg"); // backup image file
}

Public final static void main (String [] args ){
JFrame frame = new ShowImage ();
Frame. setSize (800,600 );
Frame. setdefaclocloseoperation (JFrame. EXIT_ON_CLOSE );
Frame. setVisible (true );
}
}

Class showimage_jtogglebutton?actionadapter implements ActionListener {
Private ShowImage adaptee;
Showimage_jtogglebutton?actionadapter (ShowImage adaptee ){
This. adaptee = adaptee;
}
Public void actionreceivmed (ActionEvent e ){
Adaptee. jtogglebutton?action=med (e );
}
}