Read an image from jar

Question

I have a problem reading an image file inside a jar file. I basically want to read an image file from a jar and throw it on the browser. The following is the code that I'm using.
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.net.URL;
public class ImageServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
try {
response.setContentType("image/jpeg");
InputStream inputStream = ImageServlet.class.getResourceAsStream("/duke.jpg");
//InputStream inputStream = getServletContext().getResourceAsStream("/duke.jpg");
byte x[] = new byte[inputStream.available()];
inputStream.read(x);
ByteArrayOutputStream ostr = new ByteArrayOutputStream();
ServletOutputStream outputStream = response.getOutputStream();
ostr.write(x);
ostr.writeTo(outputStream);
inputStream.close();
outputStream.close();
ostr.close();
} catch (java.net.MalformedURLException e) {
System.out.println( "URL: " + e.toString() );
} catch (java.io.IOException e) {
System.out.println("IO: no Jar! searching ..." );
} catch (Exception e) {
System.out.println(e.toString());
When duke.jpg is in web application's root, both
InputStream inputStream = ImageServlet.class.getResourceAsStream("/duke.jpg");
and
InputStream inputStream = getServletContext().getResourceAsStream("/duke.jpg");
works fine.
But when I delete it from web application's root and instead have it in a jar file in WEB-INF/lib, it doesn't work. It just gives me a broken image (doesn't throw an Exception).
Any ideas?
Thanks
Saravanan

Answer 1

Well, it should work, as long as you truly do have those SP jars ahead in the correct classpath parts (boot goes into the normal classpath, and the other one goes into the -Dweblogic.class.path (or something like that) command-line parameter). It works for me, and I know for a fact that in service pack 8 and below it's broken (don't know about service pack 9), and it got fixed in service pack 10. Sounds simple, but make certain your service pack jar files are in the directory specified in the classpath(s), and spelled correctly - you know it won't give you an error to let you know if you mistyped something, like if you included "nonexistent.jar" for example.