我也碰到了和您同樣的問題！
并且有：ava.sql.SQLException: Listener refused the connection with the following error:
ORA-12518, TNS:listener could not hand off client connection這個問題。
麻煩問您以下。該如何解決？

好象這一句總是報異常
ImageIO.write(image, "JPEG", response.getOutputStream());