JAVA-2116: Split or move libraries-data-2 module (#9716)

* JAVA-2116: Move Java-R Integration to libraries-6 module

* JAVA-2116: Move Guide to JMapper to libraries-data module

libraries-6/src/main/java/com/baeldung/r/FastRMean.java

@@ -0,0 +1,30 @@
+package com.baeldung.r;
+
+/**
+ * FastR showcase.
+ * 
+ * @author Donato Rimenti
+ */
+public class FastRMean {
+
+    /**
+     * 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
+     */
+    public double mean(int[] values) {
+        Context polyglot = Context.newBuilder()
+            .allowAllAccess(true)
+            .build();
+        String meanScriptContent = RUtils.getMeanScriptContent();
+        polyglot.eval("R", meanScriptContent);
+        Value rBindings = polyglot.getBindings("R");
+        Value rInput = rBindings.getMember("c")
+            .execute(values);
+        return rBindings.getMember("customMean")
+            .execute(rInput)
+            .asDouble();
+    }
+
+}

libraries-6/src/main/java/com/baeldung/r/RCallerMean.java

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+package com.baeldung.r;
+
+import com.github.rcaller.rstuff.RCaller;
+import com.github.rcaller.rstuff.RCallerOptions;
+import com.github.rcaller.rstuff.RCode;
+
+import java.io.IOException;
+import java.net.URISyntaxException;
+
+/**
+ * RCaller showcase.
+ * 
+ * @author Donato Rimenti
+ */
+public class RCallerMean {
+
+    /**
+     * 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 IOException        if any error occurs
+     * @throws URISyntaxException if any error occurs
+     */
+    public double mean(int[] values) throws IOException, URISyntaxException {
+        String fileContent = RUtils.getMeanScriptContent();
+        RCode code = RCode.create();
+        code.addRCode(fileContent);
+        code.addIntArray("input", values);
+        code.addRCode("result <- customMean(input)");
+        RCaller caller = RCaller.create(code, RCallerOptions.create());
+        caller.runAndReturnResult("result");
+        return caller.getParser()
+            .getAsDoubleArray("result")[0];
+    }
+
+}

libraries-6/src/main/java/com/baeldung/r/RUtils.java

@@ -0,0 +1,33 @@
+package com.baeldung.r;
+
+import java.io.IOException;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.stream.Collectors;
+
+/**
+ * Utility class for loading the script.R content.
+ * 
+ * @author Donato Rimenti
+ */
+public class RUtils {
+
+    /**
+     * Loads the script.R and returns its content as a string.
+     * 
+     * @return the script.R content as a string
+     * @throws IOException        if any error occurs
+     * @throws URISyntaxException if any error occurs
+     */
+    static String getMeanScriptContent() throws IOException, URISyntaxException {
+        URI rScriptUri = RUtils.class.getClassLoader()
+            .getResource("script.R")
+            .toURI();
+        Path inputScript = Paths.get(rScriptUri);
+        return Files.lines(inputScript)
+            .collect(Collectors.joining());
+    }
+}

libraries-6/src/main/java/com/baeldung/r/RenjinMean.java

@@ -0,0 +1,35 @@
+package com.baeldung.r;
+
+import org.renjin.script.RenjinScriptEngine;
+import org.renjin.sexp.DoubleArrayVector;
+
+import javax.script.ScriptException;
+import java.io.IOException;
+import java.net.URISyntaxException;
+
+/**
+ * Renjin showcase.
+ * 
+ * @author Donato Rimenti
+ */
+public class RenjinMean {
+
+    /**
+     * 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 IOException        if any error occurs
+     * @throws URISyntaxException if any error occurs
+     * @throws ScriptException    if any error occurs
+     */
+    public double mean(int[] values) throws IOException, URISyntaxException, ScriptException {
+        RenjinScriptEngine engine = new RenjinScriptEngine();
+        String meanScriptContent = RUtils.getMeanScriptContent();
+        engine.put("input", values);
+        engine.eval(meanScriptContent);
+        DoubleArrayVector result = (DoubleArrayVector) engine.eval("customMean(input)");
+        return result.asReal();
+    }
+
+}

libraries-6/src/main/java/com/baeldung/r/RserveMean.java

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+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();
+    }
+
+}