Serving an image from my war directory?

I have a servlet which serves an image file which was stored in a blob. If the requested image can't be found, I'd like to server a static image I have included in my war directory. How do we do this? This is how I'm serving the blob images from the datastore:

public class ServletImg extends HttpServlet {
  public void doGet(HttpServletReque开发者_如何学Pythonst req, HttpServletResponse resp)
  {
    MyImgWrapper obj = PMF.get().getPersistenceManager().
      getObjectById(MyImgWrapper.class, 'xyz');
    if (obj != null) {
      resp.getOutputStream().write(obj.getBlob().getBytes());
      resp.getOutputStream().flush();
    }
    else {
      // Here I'd like to serve an image from my war file. 
      /war/img/missingphoto.jpg
    } 
  }
}

yeah I'm just not sure how to get the image bytes from the image in my war dir, or if there's some other way to do it?

Thanks

The other answers recommending ClassLoader#getResourceAsStream() are expecting that the image is located in the classpath. You can however also obtain the image from the webcontent using ServletContext#getResourceAsStream(). The ServletContext is available in servlets by the inherited getServletContext() method.

InputStream input = getServletContext().getResourceAsStream("/img/missingphoto.jpg");

That said, reading and writing fully into/from a byte[] is not really memory efficient. Consider streaming through a small byte buffer (1~10KB) like so:

input = getServletContext().getResourceAsStream(path);
output = response.getOutputStream();
byte[] buffer = new byte[1024];
for (int length = 0; (length = input.read(buffer)) > 0;) {
    output.write(buffer, 0, length);
}

Follow Haveacafe's tutorial.

2nd result for Google: java war file resource.

I suggest you use the class loader to retrieve the file.

ClassLoader classLoader = this.getClass().getClassLoader();
InputStream in = classLoader.getResourceAsStream(fileNameInClasspath);
...

Better way at this case will be simply return http redirect (status 301) to URL of this image.