java-bridge JNI/Haskell example

gistfile1.hs

import Foreign.Java

main :: IO ()
main = do
    initJava ["-Djava.class.path=/home/horus/test"]
    runJava $ do
        Just testClass        <- getClass "Test"
        Just systemClass      <- getClass "java.lang.System"
        Just printStreamClass <- getClass "java.io.PrintStream"
        Just outField         <- getStaticField systemClass "out" (object "java.io.PrintStream")
        Just out              <- readStaticField outField
        println               <- printStreamClass `bindMethod`       "println"         ::= string --> void
        getTimeFromFile       <- testClass        `bindStaticMethod` "getTimeFromFile" ::= string --> long
        result                <- getTimeFromFile "/home/tomcat/logs/customlog.log.2015-01-11-05-01"
        println out ("Hello from JVM: " ++ show result)

-- Hello from JVM: 1420923660000