This library provides a c library for DHT11 temperature reading.
At the same time, a java API wrapped by jni is also avaiable.
This library required wiringPi be installed first. Refer: http://wiringpi.com/download-and-install/
Run build script as root:
$ sudo sh build.sh
This will install DHT library to your /usr/lib folder which could be loaded by Java through jni.
Just download files from lib and you can use it.