Nothing happening when a R file is called from my Java code

I have a java code which has R programming steps in it which is running perfectly fine. But the same R programming steps are extracted into a R file (MyScript.r) and I tried to call this file from my java code. When I run my java code nothing seems to be happening. I may look dumb with what I'm trying to achieve, may be it's true as I don't have knowledge on R. So required your help on this.

My Java code with R programming steps inside it.

package com.rtest;

import java.io.IOException;

import org.rosuda.JRI.Rengine;

public class RWithJavaTest {

    public static void main(String a[]) {

        // Create an R vector in the form of a string.
        String javaVector = "c(1,2,3,4,5)";
//      System.out.println("System.getProperty(\"java.library.path\")>>"+System.getProperty("java.library.path"));  //Prints path in env var
        // Start Rengine.
        Rengine engine = new Rengine(new String[] { "--no-save" }, false, null);

        // The vector that was created in JAVA context is stored in 'rVector'
        // which is a variable in R context.
        engine.eval("rVector=" + javaVector);

        // Calculate MEAN of vector using R syntax.
        engine.eval("meanVal=mean(rVector)");

        // Retrieve MEAN value
        double mean = engine.eval("meanVal").asDouble();

        // Print output values
        System.out.println("Mean of given vector is=" + mean);



    }
}

The above program when run, successfully giving me the output: 3.0

Java code with R programming steps included in R file and calling the R file from the java code.

package com.rtest;
import java.io.IOException;
public class RWithJavaTest {
    public static void main(String a[]) {
        try {
            System.out.println("before..");
            Runtime.getRuntime().exec("Rscript D:\\MyScript.R");
            System.out.println("after..");
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

R script:

// Create an R vector in the form of a string.
        String javaVector = "c(1,2,3,4,5)";
//      System.out.println("System.getProperty(\"java.library.path\")>>"+System.getProperty("java.library.path"));  //Prints path in env var
        // Start Rengine.
        Rengine engine = new Rengine(new String[] { "--no-save" }, false, null);

        // The vector that was created in JAVA context is stored in 'rVector'
        // which is a variable in R context.
        engine.eval("rVector=" + javaVector);

        // Calculate MEAN of vector using R syntax.
        engine.eval("meanVal=mean(rVector)");

        // Retrieve MEAN value
        double mean = engine.eval("meanVal").asDouble();

        // Print output values
        System.out.println("Mean of given vector is=" + mean);

I know what I did here is something completely wrong but seeking help on 2 things here.
1) How to correct my R Script so that it runs with out any issues
2) Java code to call the R Script, so I can see the output 3.0 once I run the code.