Add another nashorn sample of dynamically invoking java code at runtime

Author: winterbe

src/com/winterbe/java8/Nashorn7.java

@@ -0,0 +1,43 @@
+package com.winterbe.java8;
+
+import javax.script.Invocable;
+import javax.script.ScriptEngine;
+import javax.script.ScriptEngineManager;
+import javax.script.ScriptException;
+
+/**
+ * @author Benjamin Winterberg
+ */
+public class Nashorn7 {
+
+ public static class Person {
+ private String name;
+
+ public String getName() {
+ return name;
+ }
+
+ public void setName(String name) {
+ this.name = name;
+ }
+
+ public int getLengthOfName() {
+ return name.length();
+ }
+ }
+
+ public static void main(String[] args) throws ScriptException, NoSuchMethodException {
+ ScriptEngine engine = new ScriptEngineManager().getEngineByName("nashorn");
+ engine.eval("function foo(predicate, obj) { return !!(eval(predicate)); };");
+
+ Invocable invocable = (Invocable) engine;
+
+ Person person = new Person();
+ person.setName("Hans");
+
+ String predicate = "obj.getLengthOfName() >= 4";
+ Object result = invocable.invokeFunction("foo", predicate, person);
+ System.out.println(result);
+ }
+
+}