RMySQL package doesn't load through JRI interface

I've managed to install RMySQL in R, and it runs fine (I also installed its required dependency, DBI, and it works fine too). I'm building a java application that interacts with R through the JRI package (which also works fine). Currently my application queries a MySQL database, writes the query results to file, and loads these files in R (by using the load.csv() function in R). However, the program would run more efficiently if R were to interact directly with MySQL (hence the RMySQL package). The problem that I'm having is that the RMySQL package will not load in R if I try to load it by using the Rengine.eval() JRI function. However, the Rengine.eval() function will load any other library that I've tried loading. Here's a snippet of the code:

Rengine re;

re.eval("library(\"DBI\")"); // this works, DBI will load
re.eval("library(\"RMySQL\")"); // this will not work, RMySQL fails to load

To verify that RMySQL is failing to load I did this:

REXP x;
System.out.println(x=re.eval("library(\"DBI\")"));
System.out.println(x=re.eval("library(\"RMySQL\")"));

I get the following output:

[STRING* ("DBI", "stats", "graphics", "grDevices", "utils", "datasets", "methods", "base")]

null

As can be clearly seen, the second println command is returning a null which means that the RMySQL is failing to load (and of course none of the RMySQL functions work either). I have no idea why this is the case.

I don't know what it is I'm doing wrong, but if someone can tell me what the problem is, or if there is a better way of loading libraries through JRI I would much appreciate it.

Note that I am using R version 2.13.0 on sparc-sun-solaris2.10, and the RMySQL_0开发者_运维技巧.8-0 build.

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Resolved this issue by setting the environment variables R_HOME, R_INCLUDE_DIR, R_SHARE_DIR, and R_DOC_DIR before running JRI. Works now great.

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I had this type of problem before.

You probably installed RMySQL package not the correct way, e.g.

install.packages('RMySQL')

The correct way will be:

install.packages('RMySQL',type='source')

I succeeded to load the package through JRI after i installed the package with type "source".