Read/write BLOB from/to MySQL in Java

This post shows you how to insert an image into MySQL database through Java

Step 1 : Open MySQL client
Step 2 : Execute the following query

CREATE TABLE IF NOT EXISTS `image` (
IMG blob,
IMG_ID int NOT NULL AUTO_INCREMENT,
PRIMARY KEY (`IMG_ID`)
)

Source code
-----------


import java.awt.event.ActionEvent;
import java.sql.*;
import java.awt.Graphics;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import javax.imageio.ImageIO;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;



/**
*
* @author mustaq
*/
public class ImagePanel extends JPanel implements ActionListener {


JButton browse;
Connection con = null;

public ImagePanel() {
con = this.getConnection();
browse = new JButton("Browse");
browse.addActionListener(this);
this.add(browse);
}
public Connection getConnection() {
try {
// Creating connection to DB
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/image";
Connection c = DriverManager.getConnection(url,"root","");
return c;
}
catch(Exception ex) {
System.out.println(ex.getMessage());
return null;
}

}
public void imageWrite(File file) {
try {

FileInputStream io = new FileInputStream(file);
String query = "insert into image(IMG) values(?)";
java.sql.PreparedStatement stmt = con.prepareStatement(query);
stmt.setBinaryStream(1, (InputStream)io,(int)file.length());
stmt.executeUpdate();
}
catch(Exception ex) {
System.out.println(ex.getMessage());
}
}
public BufferedImage getImageById(int id) {
String query = "select IMG from image where IMG_ID = ?";
BufferedImage buffimg = null;
try {
PreparedStatement stmt = con.prepareStatement(query);
stmt.setInt(1,id);
ResultSet result = stmt.executeQuery();
result.next();
InputStream img = result.getBinaryStream(1); // reading image as InputStream
buffimg= ImageIO.read(img); // decoding the inputstream as BufferedImage

}
catch(Exception ex) {
System.out.println(ex.getMessage());
}
return buffimg;
}
@Override
public void paint(Graphics g) {

BufferedImage img = this.getImageById(5) ; // pass valid IMG_ID
if(img != null)
g.drawImage(img, 70, 20, this);

}
public static void main(String[] args) {
JFrame frame = new JFrame("ImagePanel Demo");
ImagePanel imgPanel = new ImagePanel();
frame.setVisible(true);
frame.setSize(600, 400);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(imgPanel);


}
public void actionPerformed(ActionEvent e) {
JFileChooser chooser = new JFileChooser();
int returnVal = chooser.showOpenDialog(null);
File file = null;
if(returnVal == JFileChooser.APPROVE_OPTION) {
file = chooser.getSelectedFile(); // path to image
this.imageWrite(file); // inserting image into database
JOptionPane.showMessageDialog(this, "Image inserted.", "ImageDemo", JOptionPane.PLAIN_MESSAGE);
this.repaint();

}
}

}