java调用R语言包(JRI方式),bug记录

一,软件环境

   win10  64位  +  eclipse + jdk 1.7

 

二,使用JRI方式的步骤

    2.1   首先安装rJava(两种方式)

        (1)  使用命令install.packages("rJava")安装 ;

        (2)  使用RGui的图形化界面安装;

                  程序包 --> 安装程序包 --> 选择CRAN (China (beijing 4) [https])   --> 选择rJava  确定即可;

   2.2   修改环境变量;

         (1)  在path中添加R_HOME变量(D:\Program Files\R\R-3.2.3)

         (2) 在path中添加 %R_HOME%\bin;%R_HOME%\bin\i386;%R_HOME%\library\rJava\jri;%R_HOME%\library\rJava\jri\i386

   2.3   建立java工程(Rtest)

          (1), 首先到www.rforge.net/rJava下载JRI.jar、REngine.jar和JRIEngine.jar这三个文件,导入到Rtest中;

          (2), 拷贝 rJava包安装目录下的jri/examples里有现成的例子（rtest.java和rtest2.java）到Rtest中;

          (3), 运行测试;

 

三 ,运行结果失败!

   3.1 出现如下异常

 Cannot find JRI native library!
Please make sure that the JRI native library is in a directory listed in java.library.path.
java.lang.UnsatisfiedLinkError: D:\Program Files\R\R-3.2.3\library\rJava\jri\jri.dll: Can't load IA 32-bit .dll on a AMD 64-bit platform
    at java.lang.ClassLoader$NativeLibrary.load(Native Method)
    at java.lang.ClassLoader.loadLibrary1(Unknown Source)
    at java.lang.ClassLoader.loadLibrary0(Unknown Source)
    at java.lang.ClassLoader.loadLibrary(Unknown Source)
    at java.lang.Runtime.loadLibrary0(Unknown Source)
    at java.lang.System.loadLibrary(Unknown Source)
    at org.rosuda.JRI.Rengine.<clinit>(Rengine.java:19)
    at com.rtest.rtest.main(rtest.java:62)

大致意思就是 64位的JVM不能加载32位的 .dll文件;

然后我把原来的jri.dll文件替换成64位的jri.dll文件,测试运行控制台抛出如下异常:

Cannot find JRI native library!
Please make sure that the JRI native library is in a directory listed in java.library.path.

java.lang.UnsatisfiedLinkError: D:\Program Files\R\R-3.2.3\library\rJava\jri\jri.dll: %1 不是有效的 Win32 应用程序。
    at java.lang.ClassLoader$NativeLibrary.load(Native Method)
    at java.lang.ClassLoader.loadLibrary0(ClassLoader.java:1807)
    at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1732)
    at java.lang.Runtime.loadLibrary0(Runtime.java:823)
    at java.lang.System.loadLibrary(System.java:1028)
    at org.rosuda.JRI.Rengine.(Rengine.java:19)
    at R_Test.rtest.main(rtest.java:63)

后来观察R和rJava的安装目录发现,目录下包含x64和i386(32位)文件夹,所以把2.2步骤中的环境变量全部修改指向x64文件夹;具体如下:

         %R_HOME%\bin;%R_HOME%\bin\x64;%R_HOME%\library\rJava\jri;%R_HOME%\library\rJava\jri\x64

 然后重新启动eclipse(重新加载java.library.path变量)  很重要!!!  

运行rtest.java和rtest2.java ;测试成功!