Nashorn js engine

rarques · rarques · commit f377ea157070 · 2017-02-28T19:54:17.000+01:00
diff --git a/src/java8_features/NashornJS.java b/src/java8_features/NashornJS.java
@@ -0,0 +1,50 @@
+package java8_features;
+
+import javax.script.ScriptEngine;
+import javax.script.ScriptEngineManager;
+import javax.script.ScriptException;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.InputStreamReader;
+import java.io.Reader;
+
+/**
+ * With Java 8, Nashorn, a much improved javascript engine is introduced,
+ * to replace the existing Rhino. Nashorn provides 2 to 10 times better performance.
+ * Created by nector on 28/02/17.
+ */
+public class NashornJS {
+
+    public static void main(String[] args) {
+
+        ScriptEngineManager manager = new ScriptEngineManager();
+        ScriptEngine nashorn = manager.getEngineByName("nashorn");
+
+        String name = "Nector";
+        Integer result = null;
+
+        try {
+            // eval method executes the javascript code in brackets.
+            nashorn.eval("print('" + name + "')");
+            result = (Integer) nashorn.eval("10 + 2");
+        } catch (ScriptException ex) {
+            System.err.println("Error executing script: " + ex.getMessage());
+        }
+
+        try {
+            // Create a reader from an FileInputStream and execute its script
+            Reader jsReader = new InputStreamReader(
+                    new FileInputStream("src/java8_features/TestScript.js"));
+            nashorn.eval(jsReader);
+
+        } catch (ScriptException ex2) {
+            System.err.println("Error executing script: " + ex2.getMessage());
+        } catch (FileNotFoundException ex3) {
+            System.err.println("Error finding file");
+        }
+
+        System.out.println(result.toString());
+
+    }
+
+}
diff --git a/src/java8_features/TestScript.js b/src/java8_features/TestScript.js
@@ -0,0 +1,10 @@
+/**
+ * Created by nector on 28/02/17.
+ */
+
+a = 1
+b = 2
+c = 3
+
+d = a + b + c
+print("The result is " + d)
