Nashorn scope samples

src/com/winterbe/java8/samples/nashorn/Nashorn11.java

+package com.winterbe.java8.samples.nashorn;
+
+import jdk.nashorn.api.scripting.NashornScriptEngine;
+
+import javax.script.Bindings;
+import javax.script.ScriptContext;
+import javax.script.ScriptEngineManager;
+import javax.script.ScriptException;
+import javax.script.SimpleBindings;
+import javax.script.SimpleScriptContext;
+
+/**
+ * @author Benjamin Winterberg
+ */
+public class Nashorn11 {
+
+    public static void main(String[] args) throws Exception {
+//        test1();
+//        test2();
+//        test3();
+//        test4();
+//        test5();
+//        test6();
+        test7();
+    }
+
+    private static void test7() throws ScriptException {
+        NashornScriptEngine engine = createEngine();
+
+        engine.eval("var foo = 23;");
+
+        ScriptContext defaultContext = engine.getContext();
+        Bindings defaultBindings = defaultContext.getBindings(ScriptContext.ENGINE_SCOPE);
+
+        SimpleScriptContext context1 = new SimpleScriptContext();
+        context1.setBindings(defaultBindings, ScriptContext.ENGINE_SCOPE);
+
+        SimpleScriptContext context2 = new SimpleScriptContext();
+        context2.getBindings(ScriptContext.ENGINE_SCOPE).put("foo", defaultBindings.get("foo"));
+
+        engine.eval("foo = 44;", context1);
+        engine.eval("print(foo);", context1);
+        engine.eval("print(foo);", context2);
+    }
+
+    private static void test6() throws ScriptException {
+        NashornScriptEngine engine = createEngine();
+
+        ScriptContext defaultContext = engine.getContext();
+        defaultContext.getBindings(ScriptContext.GLOBAL_SCOPE).put("foo", "hello");
+
+        ScriptContext customContext = new SimpleScriptContext();
+        customContext.setBindings(defaultContext.getBindings(ScriptContext.ENGINE_SCOPE), ScriptContext.ENGINE_SCOPE);
+
+        Bindings bindings = new SimpleBindings();
+        bindings.put("foo", "world");
+        customContext.setBindings(bindings, ScriptContext.GLOBAL_SCOPE);
+
+//        engine.eval("foo = 23;");                 // overrides foo in all contexts, why???
+
+        engine.eval("print(foo)");                  // hello
+        engine.eval("print(foo)", customContext);   // world
+        engine.eval("print(foo)", defaultContext);  // hello
+    }
+
+    private static void test5() throws ScriptException {
+        NashornScriptEngine engine = createEngine();
+
+        engine.eval("var obj = { foo: 'foo' };");
+        engine.eval("function printFoo() { print(obj.foo) };");
+
+        ScriptContext defaultContext = engine.getContext();
+        Bindings defaultBindings = defaultContext.getBindings(ScriptContext.ENGINE_SCOPE);
+
+        SimpleScriptContext context1 = new SimpleScriptContext();
+        context1.setBindings(defaultBindings, ScriptContext.ENGINE_SCOPE);
+
+        SimpleScriptContext context2 = new SimpleScriptContext();
+        context2.setBindings(defaultBindings, ScriptContext.ENGINE_SCOPE);
+
+        engine.eval("obj.foo = 'bar';", context1);
+        engine.eval("printFoo();", context1);
+        engine.eval("printFoo();", context2);
+    }
+
+    private static void test4() throws ScriptException {
+        NashornScriptEngine engine = createEngine();
+
+        engine.eval("function foo() { print('bar') };");
+
+        ScriptContext defaultContext = engine.getContext();
+        Bindings defaultBindings = defaultContext.getBindings(ScriptContext.ENGINE_SCOPE);
+
+        SimpleScriptContext context = new SimpleScriptContext();
+        context.setBindings(defaultBindings, ScriptContext.ENGINE_SCOPE);
+
+        engine.eval("foo();", context);
+        System.out.println(context.getAttribute("foo"));
+    }
+
+    private static void test3() throws ScriptException {
+        NashornScriptEngine engine = createEngine();
+
+        ScriptContext defaultContext = engine.getContext();
+        Bindings defaultBindings = defaultContext.getBindings(ScriptContext.ENGINE_SCOPE);
+
+        SimpleScriptContext context = new SimpleScriptContext();
+        context.setBindings(defaultBindings, ScriptContext.ENGINE_SCOPE);
+
+        engine.eval("function foo() { print('bar') };", context);
+        engine.eval("foo();", context);
+
+        Bindings bindings = context.getBindings(ScriptContext.ENGINE_SCOPE);
+        System.out.println(bindings.get("foo"));
+        System.out.println(context.getAttribute("foo"));
+    }
+
+    private static void test2() throws ScriptException {
+        NashornScriptEngine engine = createEngine();
+        engine.eval("function foo() { print('bar') };");
+        engine.eval("foo();", new SimpleScriptContext());
+    }
+
+    private static void test1() throws ScriptException {
+        NashornScriptEngine engine = createEngine();
+        engine.eval("function foo() { print('bar') };");
+        engine.eval("foo();");
+    }
+
+    private static NashornScriptEngine createEngine() {
+        return (NashornScriptEngine) new ScriptEngineManager().getEngineByName("nashorn");
+    }
+
+}