Displaying BLOB Stored Image in OAF



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Displaying BLOB stored image in OAFDisplaying an Image stored in the Database as BLOB on OAF Page 1. Image Bean can display any image if the file is a physical operating system file. 2. If the image is stored as a BLOB in database table, we need write java methods to display image. 3. Following article clearly explains about writing : servlet, jsp file to display a image in jsp file http://fdegrelle.over-blog.com/article-992927.html 4. A simple way to display database blob stored image in a jsp 5. One of my recent assignments was to build a web page that needed to show images that are stored in a database. 6. Having a strong PLSQL coding background the solution seemed to be close to my fingertips and I created a PLSQL function that I called through the PLSQL Gateway. 7. CREATE TABLE PHOTOS ( IMAGEID NUMBER(10), IMAGE BLOB ) / CREATE OR REPLACE PROCEDURE Display_Image(p_id NUMBER) IS Photo BLOB v_amt NUMBER DEFAULT 4096; v_off NUMBER DEFAULT 1; v_raw RAW(4096); BEGIN -- Get the blob image SELECT image INTO Photo FROM PHOTOS WHERE IMAGEID = p_id; owa_util.mime_header('images/gif'); BEGIN LOOP -- Read the BLOB dbms_lob.READ(Photo, v_amt, v_off, v_raw); -- Display image htp.prn(utl_raw.cast_to_varchar2(v_raw)); v_off := v_off + v_amt; v_amt := 4096; END LOOP; dbms_lob.CLOSE(Photo); EXCEPTION WHEN NO_DATA_FOUND THEN NULL; END; END; / 9. The web page could be called with the following URL and did what I was asked to do img src="http://machine:port/pls/myapp/display_image?p_id=12" width="115" border="0" 10. 11. This works like a charm but has a caveat that I discovered when presenting it to the network department. The network department didn’t like the idea of exposing the database server to the Internet, which indeed is considerably unsafe. 12. Back to the whiteboard, I thought of using Web Service. This approach just didn’t feel right and appeared to be too complex for this little solution to build. Eventually I decided to write a JavaServer Page to do the job. 13. The Java class to stream the image from the database column package image; import java.sql.*; import java.io.*; import java.util.*; import oracle.jdbc.*; import oracle.sql.*; public class images { /*------------------------- * Get the Blob image *------------------------*/ public static byte[] getPhoto (OracleConnection conn, int iNumPhoto) throws Exception, SQLException { String req = "" ; Blob img ; byte[] imgData = null ; Statement stmt = conn.createStatement (); // Query req = "Select image From IMAGES Where ImageID = " + iNumPhoto ; ResultSet rset = stmt.executeQuery ( req ); while (rset.next ()) { img = rset.getBlob(1); imgData = img.getBytes(1,(int)img.length()); } rset.close(); stmt.close(); return imgData ; } } 14. The JavaServer Page includes the bean so its methods can be accessed in the JSP page using scriplets and “photo” as a named bean reference 15. <%@ page import = "image.*" %> <%@ page import = "java.io.*" %> <%@ page import = "oracle.jdbc.OracleConnection" %> <jsp:useBean id="photo" class="image.images" scope="session" /> <% int iNumPhoto ; oracle.jdbc.driver.OracleConnection conn = null; if ( request.getParameter("imgID") != null ) { iNumPhoto = Integer.parseInt(request.getParameter("imgID")) ; try { conn = …………; conn.setAutoCommit (false); // get the image from the database byte[] imgData = photo.getPhoto( conn, iNumPhoto ) ; // display the image response.setContentType("image/gif"); OutputStream o = response.getOutputStream(); o.write(imgData); o.flush(); o.close(); } catch (Exception e) { e.printStackTrace(); throw e; } finally { … Close the connexion … ; } } %> 16. To display the image on the web, I now use the following image URL img src="image.jsp?imgID=12" width="115" border="0" 17. 18. Special thank you to Frank Nimphius for its good suggestions on the style ;o) 19. Francois 20. To display image in OAF you can make use of following code. imageBean1.setImageSource("/OA_HTML/image.jsp?imgID=164"); 4. Other alternative approach for showing the image in OAF page.
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