How to display the content of a BLOB column in a ADF/BC pages ?

Question

How to display the content of a BLOB column in a ADF/BC pages ?
There is some image in database table blog column. And we want to display image on the screeen.
There is some example about upload and dowload blog columns.
(steve not yet document example page etc...)
But We want to display blog picture in a image component...
is there any basic way to do it ?
Thanks a lot...

Answer 1

Ali,
You could just download the sample app... but... here is the servlet code from the demo (look at it just for technique - you'll obviously have to change it for your needs)...
John
package oracle.fodemo.storefront.servlet;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import javax.servlet.*;
import javax.servlet.http.*;
import oracle.jbo.ApplicationModule;
import oracle.jbo.Key;
import oracle.jbo.Row;
import oracle.jbo.ViewObject;
import oracle.jbo.client.Configuration;
import oracle.jbo.domain.BlobDomain;
import oracle.jbo.domain.DBSequence;
import oracle.jbo.domain.Number;
import oracle.jbo.server.ViewObjectImpl;
public class ImageServlet
  extends HttpServlet
  private static final String CONTENT_TYPE =
    "image/jpg; charset=windows-1252";
  public void init(ServletConfig config)
    throws ServletException
    super.init(config);
  public void doGet(HttpServletRequest request,
                    HttpServletResponse response)
    throws ServletException, IOException
    response.setContentType(CONTENT_TYPE);
    response.setContentType(CONTENT_TYPE);
    String detailProductId = request.getParameter("detail");
    String thumbnailProductId = request.getParameter("thumbnail");
    boolean thumbnail = true;
    String productId = null;
    OutputStream os = response.getOutputStream();
    String amDef = "oracle.fodemo.storefront.store.service.StoreServiceAM";
    String config = "StoreServiceAMLocal";
    ApplicationModule am =
      Configuration.createRootApplicationModule(amDef, config);
    ViewObjectImpl vo =
      (ViewObjectImpl) am.findViewObject("ProductImages"); // get view object (the same as used in the table)
    if (detailProductId != null)
      productId = detailProductId;
      thumbnail = false;
    else
      productId = thumbnailProductId;
    vo.defineNamedWhereClauseParam("paramThumbnail", null, null);
    vo.defineNamedWhereClauseParam("paramProductId", null, null);
    vo.setWhereClause("DEFAULT_VIEW_FLAG = :paramThumbnail AND PRODUCT_ID = :paramProductId");
    vo.setNamedWhereClauseParam("paramThumbnail", (thumbnail? "Y": "N"));
    vo.setNamedWhereClauseParam("paramProductId", productId);
    vo.executeQuery();
    Row product = vo.first();
    BlobDomain image = (BlobDomain) product.getAttribute("Image");
    InputStream is = image.getInputStream();
    // copy blob to output
    byte[] buffer = new byte[10 * 1024];
    int nread;
    while ((nread = is.read(buffer)) != -1)
      os.write(buffer, 0, nread);
    os.close();
    vo.setWhereClause(null);
    vo.removeNamedWhereClauseParam("paramProductId");
    vo.removeNamedWhereClauseParam("paramThumbnail");
    Configuration.releaseRootApplicationModule(am, false);
}