4
我目前正在開發一個R包來在R中集成Java代碼。但是,我遇到了嘗試正確調用java類方法的問題。到目前爲止,我已經獨立開發並編譯了一個Java程序到一個類文件中,然後將其打包爲一個jar文件。我的代碼樣本如下:rjava .jcall問題
library(rJava)
.jinit()
.onLoad <- function(lib, pkg) {
pathToSdk <- paste(system.file(package = "mailViz") , "C:\\path\\to\\libs", sep="")
jarPaths <- c(paste(pathToSdk, "mail.jar", sep=""),
paste(pathToSdk, "mailReader.jar", sep="")
)
.jpackage(pkg, morePaths=jarPaths)
attach(javaImport(c("java.lang", "java.io", "java.mail", "java.util", "java.text")))
packageStartupMessage(paste("mailViz loaded. The classpath is: ", paste(.jclassPath(), collapse=" ")))
}
# get method arguments for the class
#.jmethods("mailReader","readEmailInfo")
z=.jcall("mailReader", "Ljava/lang/String;", "readEmailInfo", "username", "password")
然而,當我執行.jcall功能我收到一個錯誤:
Error in .jcall("mailReader", "Ljava/lang/String;", "readEmailInfo", "username", :
method readEmailInfo with signature (Ljava/lang/String;Ljava/lang/String;)Ljava/lang/String; not found
我試圖改變參數,但沒有運氣的多種方式。當我運行的類文件.jmethods(「郵件閱讀器」),它列出了所有可用的方法:到
[2] "public java.lang.String mailReader.readEmailInfo(java.lang.String,java.lang.String)"
所以,我在如何進行正確調用傳遞兩個參數(用戶名,密碼)很失落java類文件。
有什麼想法?在此先感謝,
P