Re: binary data

[Christian Mack]

Thomas Kwan wrote:
< ... > 
> Hello Christian,
> 
> Yes, please, an example will help a lot. I did not
> use PreparedStatement before.
> 
> thomas

Hi Thomas, James and others

In this example I assume, that you have successfully loaded the twz or mm driver.
Also you should already be connected to the database of your choice through a
java.sql.Connection object called "con".
The bytes are read from a file "test.gif".

import java.lang.*;
import java.sql.*;
import java.io.*;
...
        // read the bytes
        byte[] image = new byte[80 * 1024];
        byte[] realImage;
        FileInputStream gifImage = new FileInputStream("test.gif");
        int count = gifImage.read( image );
        realImage = new byte[ count ];
        System.arraycopy( image, 0, realImage, 0, count );
        
        // create a PreparedStatement for storing the bytes into a table like this:
        // id INT NOT NULL PRIMARY KEY AUTO_INCREMENT
        // image_name VARCHAR(30) NOT NULL
        // image_bin MEDIUMBLOB
        PreparedStatement prep;
        prep = con.prepareStatement("INSERT INTO table (id,image_name,image_bin)"
                                        + " VALUES (?,?,?)"
                                        );
        
        // ensure, the internal buffers can handle up to 80KBytes
        prep.setMaxFieldSize( 80 * 1024 );
        
        // set the values to store:
        prep.setNull( 1, Types.INTEGER );
        prep.setString( 2, "test image No.1" );
        prep.setBytes( 3, realImage );
        
        // start the query
        prep.executeUpdate();
        
        // stop binary processing
        prep.close();
....

You obviously have to catch yourself all IOExceptions and SQLExceptions that can occur in
this piece of code.

Hope this helps.
Christian