tests/testthat/otherExamples.R

In CWFC-CCFB/J4R: Create 'Java' Objects and Execute 'Java' Methods

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# Examples for public servers or debug
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### Example for debugging (see wiki)
require(J4R)
connectToJava(port = 18011:18012, internalPort = 50000:50001, public=T, key=1000000)

myArray <- createJavaObject("java.util.ArrayList")
myArray$add(5)

shutdownClient()


#### Example public sorver running on local host within existing app ####

require(J4R)
connectToJava(port = 18000, internalPort = 50000:50001, public=T, key=212)

defaultCharset <- callJavaMethod("java.nio.charset.Charset", "defaultCharset")
print(paste("Encoding on JVM set to", defaultCharset$toString()))

myArray <- createJavaObject("java.util.ArrayList")
myArray$add(5)

obj <- getMainInstance()
obj$toString()
obj$add(5)

shutdownClient()

connectToJava(port = 18000, internalPort = 50000:50001, public=T, key=212)  ### reconnection
obj <- getMainInstance()
obj$get(as.integer(0))

shutdownClient()

#### Example public sorver running on local host running as main app ####

require(J4R)
connectToJava(port = 18000, internalPort = 50000:50001, public=T, key=212)

defaultCharset <- callJavaMethod("java.nio.charset.Charset", "defaultCharset")
print(paste("Encoding on JVM set to", defaultCharset$toString()))

myArray <- createJavaObject("java.util.ArrayList")
myArray$add(5)

myArray$toString()
shutdownClient()

connectToJava(port = 18000, internalPort = 50000:50001, public=T, key=212)  ### reconnection

shutdownClient()


#### Example public sorver running on remote host ####

require(J4R)
connectToJava(host="192.168.0.194", port = 18000:18001, internalPort = 50000:50001, public=T, key=212)

defaultCharset <- callJavaMethod("java.nio.charset.Charset", "defaultCharset")
print(paste("Encoding on JVM set to", defaultCharset$toString()))

obj <- getMainInstance()
obj$toString()

a <- createJavaObject("java.lang.String", "ééé")
a

shutdownClient()


connectToJava(host="192.168.0.194", port = 18000:18001, internalPort = 50000:50001, public=T, key=212)  ### reconnection

killJava()


#### Example iterating on map or table ####

require(J4R)
connectToJava()
myHashTable <- createJavaObject("java.util.Hashtable")
myHashTable$put("Monday", as.integer(1))
myHashTable$put("Tuesday", as.integer(5))
myHashTable$put("Wednesday", as.integer(7))

iterator <- myHashTable$keySet()$iterator()
while(iterator$hasNext()) {
  key <- callJavaMethod(iterator, "next")
  value <- myHashTable$get(key)
  print(paste("Key:", key, "; Value:", value))
}

#### Manual test to check if setJavaPath properly works when contains spaces ####

require(J4R)
getJavaVersion()
myPath <- file.path("C:","Program Files","Java","jdk-17","bin", "java.exe")
setJavaPath(myPath)
connectToJava()
getJavaVersion()
shutdownClient()
setJavaPath("")