Hi,
I'm new to Processing and working with the MySQL library. I'm trying to get a photo from a MySQL database to load into my applet, then apply a red tint and transparency once displayed.

Here is a portion of my code:

if (msql.connect () ) {
   msql.query ("SELECT photo FROM database.table");
   
   while (msql.next() ) {
     String blob = (String) msql.getObject("photo");
      }
  }
  else {
  }
  }
void draw () {
   dbphoto = loadImage ("photo");
    tint (200,0,2,126); // Tint red and set transparency
    image (dbphoto,50,50);
}


Any help would be greatly appreciated!

You can use javax.imageio.ImageIO to read an image from a file, input stream, or URL. javax.imageio is a package added since J2SE 1.4. I have utilized it with the getByteStream from the JDBC Blob object to retrieve an image. This is a sample applet I put together:

import java.awt.Image;
import java.io.BufferedInputStream;
import java.sql.Blob;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

import javax.imageio.ImageIO;

import processing.core.PApplet;
import processing.core.PImage;

@SuppressWarnings("serial")
public class ImageViewer extends PApplet {
   PImage pic = null;

   public void setup() {
       Connection conn = null;
       ResultSet rs = null;
       BufferedInputStream is = null;

       try {
           // create connection and retrieve the blob
           Class.forName("org.gjt.mm.mysql.Driver");
           String url = "jdbc:mysql://localhost:3306/blobtest";
           String user = "root";
           String password = "password";

           conn = DriverManager.getConnection(url, user, password);
           Statement stmt = conn.createStatement();
           rs = stmt
                   .executeQuery("select photo from photoTable where id = 'Something'");

           if (rs.next()) {
               // retrieve tbe image using ImageIO
               Blob blob = rs.getBlob("photo");
               is = new BufferedInputStream(blob.getBinaryStream());

               Image raw = ImageIO.read(is);
               pic = new PImage(raw);
           }
       } catch (Exception e) {
       } finally {
           try {
               is.close();
           } catch (Exception e) {
               // add exception handling
               e.printStackTrace();
           }
           try {
               rs.close();
               conn.close();
           } catch (Exception e) {
               // add exception handling
               e.printStackTrace();
           }

       }
   }

   public void draw() {  
       // display the image
       if (pic != null) {
           image(pic, 0, 0);
       }
       noLoop();
   }
}

btw, i got the JDBC code to run and it works fine.. but i think it's having issues displaying the awt-generated images from within Processing, and you may be forced to embed your Processing sketch.

sweet. this way, i may be able to eliminate the awt image functions altogether..

is "bytes" a data type, or should i create an array of bytes with "byte[]" ? and if "bytes" is its own data type, is this the sort of object that needs to be passed to the image creation function?

by the way, neither method worked natively in Processing, but i mixed the two methods (using the mysql wrapper library for db, but ImageIO for binary stream) and got it to compile in Eclipse. i had to do a bit of JAR tweaking, but it worked.

i'll get to writing my walkthrough for adding your applets to java programs.. but for now, here is the java source code.

MainClass.java
Code:

package curseMap;

import de.bezier.mysql.*;

import java.awt.*;
import java.io.*;
import java.util.*;

import javax.imageio.ImageIO;

import processing.core.*;


// applet class
//
public class MainClass extends PApplet {

private static final long serialVersionUID = 1L;
ArrayList tiles = new ArrayList();
int[][] map = new int[9][9];
int x, y;
MySQL msql;

// initializing function
//
public void setup()
{
  grabTiles();
  x = 4;
  y = 4;
  grabMap("newbie_zone");
  size(288, 288);
  background(0);
}
 
// main applet function
//
public void draw()
{
  for(int a = 0; a < 9; a++){
    for(int b = 0; b < 9; b++){
      image((PImage) tiles.get(map[a][b]), b*32, a*32);
    }
  }
      
  noLoop();
}
    
// populate tiles list
//
public void grabTiles()
{
    String db = "db";
    String user = "user"; 
    String password = "password";
    int a = 0;
    
    msql = new MySQL("some.server.com", db, user, password, this);
    
    if(msql.connect()){    
      msql.query("select blob_content, blob_id from tiles__map order by blob_id asc"); 
    
    while (msql.next()) {
      try {
        java.sql.Blob blob = msql.result.getBlob("blob_content");
        InputStream is = blob.getBinaryStream(); 
        Image raw = ImageIO.read(is); 
        PImage norm = new PImage(raw);
        tiles.add(a++, norm);
    } catch (Exception e) {
        e.printStackTrace();
    }
   }
  }
}

// populate map cells
//
public void grabMap(String mapName)
{
  String tbl = "map__" + mapName;
  String db = "db";
  String user = "user"; 
  String password = "password";
 
  msql = new MySQL("some.host.com", db, user, password, this);
  
  if(msql.connect()){  
    msql.query("select x, y, tile from " + tbl + " where "
      + "x >= " + (x - 4) + " AND "
      + "x <= " + (x + 4) + " AND "
      + "y >= " + (y - 4) + " AND "
      + "y <= " + (y + 4)
      + " order by x asc, y asc");     

  msql.next();

  for(int a = 0; a < 9; a++)
    for(int b = 0; b < 9; b++)
      if(msql.getInt("x") != a || msql.getInt("y") != b){
        map[b][a] = 0;
      } else {
        map[b][a] = msql.getInt("tile");
        msql.next();
      }
  }
}

static public void main(String args[]) {
  PApplet.main(new String[] { "curseMap.MainClass" });
}

}
 

ExampleFrame.java
Code:

package curseMap;

import java.awt.BorderLayout;
import java.awt.Frame;

import processing.core.*;

public class ExampleFrame extends Frame {

  private static final long serialVersionUID = 1L;

  public ExampleFrame() {
    super("Embedded PApplet");
    setLayout(new BorderLayout());
    PApplet embed = new curseMap.MainClass();
    add(embed, BorderLayout.CENTER);

    // important to call this whenever embedding a PApplet.
    // It ensures that the animation thread is started and
    // that other internal variables are properly set.
    embed.init();
  }
}