Java ImageIO.write() takes up to 6 seconds

Question

I am writing an web application where I need to send an image from servlet to client. Image is generated dynamically and is quite big(+-2MB). It might be jpeg, png, or gif.<

Answer 1

Image encoding in java is pretty slow in general but you may also want to ensure you have the native libraries installed as they make quite a noticeable difference in performance.

http://download.java.net/media/jai-imageio/builds/release/1.1/INSTALL-jai_imageio.html

Answer 2

Be aware that ImageIO by default uses temporary files as cache when creating ImageInputStreams and ImageOutputStreams. This can be switched off by calling ImageIO.setUseCache(false).

For a more detailed explanation see this answer.

Answer 3

Are you sure that the

ImageIO

takes so long - maybe there is another problem, e.g.

• slow (network) connection to the client
• the generation (calculation) of the image takes a lot of time