[BAEL-3489] Added Java-R integration examples.

libraries-data-2/src/main/java/com/baeldung/r/RserveMean.java

@@ -0,0 +1,29 @@
+package com.baeldung.r;
+
+import org.rosuda.REngine.REXPMismatchException;
+import org.rosuda.REngine.REngineException;
+import org.rosuda.REngine.Rserve.RConnection;
+
+/**
+ * Rserve showcase.
+ * 
+ * @author Donato Rimenti
+ */
+public class RserveMean {
+
+	/**
+	 * Connects to the Rserve istance listening on 127.0.0.1:6311 and invokes the
+	 * customMean R function passing the given values as arguments.
+	 * 
+	 * @param values the input to the mean script
+	 * @return the result of the R script
+	 * @throws REngineException      if any error occurs
+	 * @throws REXPMismatchException if any error occurs
+	 */
+	public double mean(int[] values) throws REngineException, REXPMismatchException {
+		RConnection c = new RConnection();
+		c.assign("input", values);
+		return c.eval("customMean(input)").asDouble();
+	}
+
+}