JTransforms is the first, open source, multithreaded FFT library written in pure Java. Benchmark results show better performance than FFTW.
'com.github.rwl:jtransforms:2.4.0'
<dependency>
<groupId>com.github.rwl</groupId>
<artifactId>jtransforms</artifactId>
<version>2.4.0</version>
</dependency>
<dependency org="com.github.rwl" name="jtransforms" rev="2.4.0"/>
"com.github.rwl", "jtransforms", "2.4.0"