To begin with, as far as i know there are no native opensource Java OCR SDKs. There are Java APIs which wrap calls for native interfaces, tesjeract (http://code.google.com/p/tesjeract/) or Tess4J (http://tess4j.sf.net/).
Next, you need to specify whether you look for handwritten or handprinted text. If you need handwriting text recognition - i don't beleive you'll be able to solve your tasks because of the reasons stated in other answers.
However, if you need ICR (that stands for intelligent character recognition) for handprinted text (rather clear letters used in surveys, forms, etc.) there could be a solution. While I beleive that tesseract (despite being considered the best among opensource engines) won't do the job for you here, you can look for more accurate SDKs.
Maybe this question would help: Handwritten scanned Doc to .txt File?