gnu: Add java-javaewah.

* gnu/packages/java.scm (java-javaewah): New variable.

gnu/packages/java.scm

@@ -4121,6 +4121,36 @@ (define-public java-commons-daemon
 This is a part of the Apache Commons Project.")
     (license license:asl2.0)))
 
+(define-public java-javaewah
+  (package
+    (name "java-javaewah")
+    (version "1.1.6")
+    (source (origin
+              (method url-fetch)
+              (uri (string-append "https://github.com/lemire/javaewah/"
+                                  "archive/JavaEWAH-" version ".tar.gz"))
+              (sha256
+               (base32
+                "1n7j1r1h24wlhwv9zdcj6yqjrhma2ixwyzm15l5vrv6yqjs6753b"))))
+    (build-system ant-build-system)
+    (arguments `(#:jar-name "javaewah.jar"))
+    (inputs
+     `(("java-junit" ,java-junit)
+       ("java-hamcrest-core" ,java-hamcrest-core)))
+    (home-page "https://github.com/lemire/javaewah")
+    (synopsis "Compressed alternative to the Java @code{BitSet} class")
+    (description "This is a word-aligned compressed variant of the Java
+@code{Bitset} class.  It provides both a 64-bit and a 32-bit RLE-like
+compression scheme.  It can be used to implement bitmap indexes.
+
+The goal of word-aligned compression is not to achieve the best compression,
+but rather to improve query processing time. Hence, JavaEWAH tries to save CPU
+cycles, maybe at the expense of storage.  However, the EWAH scheme is always
+more efficient storage-wise than an uncompressed bitmap (as implemented in the
+@code{BitSet} class by Sun).")
+    ;; GPL2.0 derivates are explicitly allowed.
+    (license license:asl2.0)))
+
 (define-public antlr2
   (package
     (name "antlr2")