Nashorn second Attempt (#923)

* Nashorn

* Nashorn x2

* Nashorn added trailing newlines

* Cleanup

* Formatted script lines

* Change system outs to asserts

* Change Nashorn to be Junit tests

* Remove empty test

core-java/src/main/java/com/baeldung/scripting/Nashorn.java

@@ -1,48 +0,0 @@
-package com.baeldung.scripting;
-
-import javax.script.Bindings;
-import javax.script.Invocable;
-import javax.script.ScriptEngine;
-import javax.script.ScriptEngineManager;
-import javax.script.ScriptException;
-
-public class Nashorn {
-    public static void main(String[] args) throws ScriptException, NoSuchMethodException {
-        ScriptEngine engine = new ScriptEngineManager().getEngineByName("nashorn");
-
-        Object result = engine.eval(
-                "var greeting='hello world';" +
-                        "print(greeting);" +
-                        "greeting");
-
-        System.out.println(result);
-
-        Bindings bindings = engine.createBindings();
-        bindings.put("count", 3);
-        bindings.put("name", "baeldung");
-
-        String script = "var greeting='Hello ';" +
-                "for(var i=count;i>0;i--) { " +
-                "greeting+=name + ' '" +
-                "}" +
-                "greeting";
-
-        Object bindingsResult = engine.eval(script, bindings);
-        System.out.println(bindingsResult);
-
-        engine.eval("function composeGreeting(name) {" +
-                "return 'Hello ' + name" +
-                "}");
-        Invocable invocable = (Invocable) engine;
-
-        Object funcResult = invocable.invokeFunction("composeGreeting", "baeldung");
-        System.out.println(funcResult);
-
-        Object map = engine.eval("var HashMap = Java.type('java.util.HashMap');" +
-                "var map = new HashMap();" +
-                "map.put('hello', 'world');" +
-                "map");
-
-        System.out.println(map);
-    }
-}

core-java/src/main/resources/js/bind.js

@@ -0,0 +1,15 @@
+var first = {
+    name: "Whiskey",
+    age: 5
+};
+
+var second = {
+    volume: 100
+};
+
+Object.bindProperties(first, second);
+
+print(first.volume);
+
+second.volume = 1000;
+print(first.volume);

core-java/src/main/resources/js/locations.js

@@ -0,0 +1 @@
+print(__FILE__, __LINE__, __DIR__);

core-java/src/main/resources/js/math_module.js

@@ -0,0 +1,19 @@
+var math = {
+    increment: function (num) {
+        return ++num;
+    },
+
+    failFunc: function () {
+        try {
+            throw "BOOM";
+        } catch (e if typeof e === 'string') {
+            print("String thrown: " + e);
+        }
+        catch (e) {
+            print("this shouldn't happen!");
+        }
+    }
+};
+
+
+math;

core-java/src/main/resources/js/no_such.js

@@ -0,0 +1,11 @@
+var demo = {
+    __noSuchProperty__: function (propName) {
+        print("Accessed non-existing property: " + propName);
+    },
+
+    __noSuchMethod__: function (methodName) {
+        print("Invoked non-existing method: " + methodName);
+    }
+};
+
+demo;

core-java/src/main/resources/js/script.js

@@ -0,0 +1 @@
+function increment(num) ++num;

core-java/src/main/resources/js/trim.js

@@ -0,0 +1,2 @@
+print("   hello world".trimLeft());
+print("hello world     ".trimRight());

core-java/src/main/resources/js/typed_arrays.js

@@ -0,0 +1,9 @@
+function arrays(arr) {
+
+    var javaIntArray = Java.to(arr, "int[]");
+    print(javaIntArray[0]);
+    print(javaIntArray[1]);
+    print(javaIntArray[2]);
+}
+
+arrays([100, "1654", true]);

core-java/src/test/java/com/baeldung/scripting/NashornTest.java

@@ -0,0 +1,134 @@
+package com.baeldung.scripting;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.io.InputStreamReader;
+import java.util.List;
+import java.util.Map;
+
+import javax.script.Bindings;
+import javax.script.Invocable;
+import javax.script.ScriptEngine;
+import javax.script.ScriptEngineManager;
+import javax.script.ScriptException;
+
+public class NashornTest {
+
+    private ScriptEngine engine;
+
+    @Before
+    public void setUp() {
+        engine = new ScriptEngineManager().getEngineByName("nashorn");
+    }
+
+    @Test
+    public void trim() throws ScriptException {
+        engine.eval(new InputStreamReader(NashornTest.class.getResourceAsStream("/js/trim.js")));
+    }
+
+    @Test
+    public void locations() throws ScriptException {
+        engine.eval(new InputStreamReader(NashornTest.class.getResourceAsStream("/js/locations.js")));
+    }
+
+    @Test
+    public void bindProperties() throws ScriptException {
+        engine.eval(new InputStreamReader(NashornTest.class.getResourceAsStream("/js/bind.js")));
+    }
+
+    @Test
+    public void magicMethods() throws ScriptException {
+        engine.eval("var demo = load('classpath:js/no_such.js');" +
+                "var tmp = demo.doesNotExist;" +
+                "var none = demo.callNonExistingMethod()");
+    }
+
+    @Test
+    public void typedArrays() throws ScriptException {
+        engine.eval(new InputStreamReader(NashornTest.class.getResourceAsStream("/js/typed_arrays.js")));
+    }
+
+    @Test
+    public void basicUsage() throws ScriptException {
+        Object result = engine.eval("var greeting='hello world';" +
+                "print(greeting);" +
+                "greeting");
+
+        Assert.assertEquals("hello world", result);
+    }
+
+    @Test
+    public void jsonObjectExample() throws ScriptException {
+        Object obj = engine.eval("Java.asJSONCompatible({ number: 42, greet: 'hello', primes: [2,3,5,7,11,13] })");
+        Map<String, Object> map = (Map<String, Object>) obj;
+
+        Assert.assertEquals("hello", map.get("greet"));
+        Assert.assertTrue(List.class.isAssignableFrom(map.get("primes").getClass()));
+    }
+
+    @Test
+    public void tryCatchGuard() throws ScriptException {
+        engine.eval("var math = loadWithNewGlobal('classpath:js/math_module.js');" +
+                "math.failFunc();");
+    }
+
+    @Test
+    public void extensionsExamples() throws ScriptException {
+        String script = "var list = [1, 2, 3, 4, 5];" + "var result = '';" +
+                "for each (var i in list) {" +
+                "result+=i+'-';" +
+                "};" +
+                "print(result);";
+        engine.eval(script);
+    }
+
+    @Test
+    public void bindingsExamples() throws ScriptException {
+        Bindings bindings = engine.createBindings();
+        bindings.put("count", 3);
+        bindings.put("name", "baeldung");
+
+        String script = "var greeting='Hello ';" +
+                "for(var i=count;i>0;i--) { " +
+                "greeting+=name + ' '" +
+                "}" +
+                "greeting";
+
+        Object bindingsResult = engine.eval(script, bindings);
+        Assert.assertEquals("Hello baeldung baeldung baeldung ", bindingsResult);
+    }
+
+    @Test
+    public void jvmBoundaryExamples() throws ScriptException, NoSuchMethodException {
+        engine.eval("function composeGreeting(name) {" +
+                "return 'Hello ' + name" +
+                "}");
+
+        Invocable invocable = (Invocable) engine;
+
+        Object funcResult = invocable.invokeFunction("composeGreeting", "baeldung");
+        Assert.assertEquals("Hello baeldung", funcResult);
+
+        Object map = engine.eval("var HashMap = Java.type('java.util.HashMap');" +
+                "var map = new HashMap();" +
+                "map.put('hello', 'world');" +
+                "map");
+
+        Assert.assertTrue(Map.class.isAssignableFrom(map.getClass()));
+    }
+
+    @Test
+    public void loadExamples() throws ScriptException {
+        Object loadResult = engine.eval("load('classpath:js/script.js');" +
+                "increment(5)");
+
+        Assert.assertEquals(6.0, loadResult);
+
+        Object math = engine.eval("var math = loadWithNewGlobal('classpath:js/math_module.js');" +
+                "math.increment(5);");
+
+        Assert.assertEquals(6.0, math);
+    }
+}