if(age>=18){

    print('Old enough to vote!');

}else{

    print('Back to school!');

}

if(age<25){

    riskFactor = 1.5;

}else if(noClaims){

    ristFactor = 0.75;

}else{

    ristFactor = 1.0;

}

function Hello(){}

Hello.prototype.sayHello = function(value){

    println('hello!'+value);

}

var hello = new Hello();

hello.sayHello('World1');

   //使用脚本引擎运行脚本程序

    public static void test01() throws ScriptException{

       // 如果调用者可访问线程上下文 ClassLoader，则调用此构造方法的效果与调用 ScriptEngineManager(Thread.currentThread().getContextClassLoader()) 相同

        //ScriptEngineManager检索感兴趣的脚本编写的语言的ScriptEngine对象

        ScriptEngineManager manager = new ScriptEngineManager();

       ScriptEngine engine = manager.getEngineByName("js");//ScriptEngine用来处理脚本解释和求值

        engine.put("age", 26);//赋值脚本环境中所使用的变量

        engine.eval("if(age>=18){println('Old enough to vote!');}else{println('Back to school!');}");//解析 JavaScript 脚本,对脚本表达式进行求值

    }

   //使用脚本引擎执行外部资源中的脚本

    public static void test02() throws FileNotFoundException, ScriptException{

        ScriptEngineManager manager = new ScriptEngineManager();

        ScriptEngine engine = manager.getEngineByName("js");

        engine.put("age", 26);

        engine.eval(new FileReader("E:/ScriptEngine/test01.js"));//对文件或其它外部资源中得脚本表达式进行求值

    }

    //使用脚本引擎检索结果

    public static void test03() throws FileNotFoundException, ScriptException{

        ScriptEngineManager manager = new ScriptEngineManager();

        ScriptEngine engine = manager.getEngineByName("js");

        engine.put("age", 26);

        engine.put("noClaims", Boolean.TRUE);

        Object result = engine.eval(new FileReader("E:/ScriptEngine/test02.js"));//eval()函数返回执行脚本后所返回的值，默认情况下，将返回上次执行的表达式的值

        System.out.println(result.toString());

    }

    //上下文属性的作用域

    public static void test04() throws ScriptException{

        ScriptEngineManager manager = new ScriptEngineManager();

        Bindings globalBindings = manager.getBindings();//属于ScriptEngineManager的全局上下文,每个ScriptEngineManager拥有一个Bindings

        globalBindings.put("name", "yangYong");

        ScriptEngine engine = manager.getEngineByName("js");

        Bindings globalBindings02 = engine.getBindings(ScriptContext.GLOBAL_SCOPE);//每个引擎都共有一个ScriptEngineManager的Bindings

        System.out.println("name="+globalBindings02.get("name"));

        System.out.println(globalBindings==globalBindings02);

        ScriptContext context = engine.getContext();//每个引擎都有自己独立的scriptContext上下文

         Bindings engineDefaultBindings = engine.getBindings(ScriptContext.ENGINE_SCOPE);//每个引擎的scriptContext中都有个默认属于自己的Bindings

        engineDefaultBindings.put("gender", "男");

        engine.eval("name2 = name;println(name2);",engineDefaultBindings);

        engineDefaultBindings.put("name", "zhangSan");

        engine.eval("name2 = name;println(name2);",engineDefaultBindings);

        Bindings engineCreatBindings = engine.createBindings();//每个引擎的scriptContext中也可以新建多个属于自己的Bindings

        engineCreatBindings.put("gender", "女");

        System.out.println(engineDefaultBindings==engineCreatBindings);

        System.out.println(engine.getBindings(ScriptContext.ENGINE_SCOPE).get("gender"));

        System.out.println(engineCreatBindings.get("gender"));

        engine.eval("name2 = name;println(name2);",engineCreatBindings);

    }

    //java应用程序与脚本交互

    public static void test05() throws FileNotFoundException, ScriptException{

        ScriptEngineManager manager = new ScriptEngineManager();

        ScriptEngine engine = manager.getEngineByName("js");

        Bindings bindings = engine.createBindings();//Bindings:KV对映射，用来在Java应用程序和javascript脚本之间交换信息，即上下文

         bindings.put("age", 26);

        bindings.put("noClaims", Boolean.TRUE);

        bindings.put("riskFactor", 1.0);

        engine.eval("if(age<25){riskFactor = 1.5;}else if(noClaims){ristFactor = 0.75;}else{ristFactor = 1.0;}",bindings);//必须绑定bindings执行脚本，否则报变量未定义异常

         double risk = (Double) bindings.get("riskFactor");

        System.out.println(risk);

    }

    //脚本内部访问java资源

    public static void test06() throws ScriptException{

        ScriptEngineManager manager = new ScriptEngineManager();

        ScriptEngine engine = manager.getEngineByName("js");

        engine.eval("importPackage(java.util)");//importPackage()函数允许在脚本内部导入java包，即可在脚本中实例化java对象

         engine.eval("today = new Date();println(today);");

        engine.put("name", "ZhangSan");

        engine.eval("name2 = name.toUpperCase();println(name2);");

    }

    //重定向脚本输出

    public static void test07() throws IOException, ScriptException{

        ScriptEngineManager manager = new ScriptEngineManager();

        ScriptEngine engine = manager.getEngineByName("js");

        PipedReader pr = new PipedReader();

        PipedWriter pw = new PipedWriter(pr);

        //用户可以通过与这个 PrintWriter 连通的 PrintReader 读取实际的输出，使 Java 应用程序能获取脚本运行输出

         PrintWriter out = new PrintWriter(pw);

        engine.getContext().setWriter(out);

        engine.eval("println('hello from javascript!');");

        BufferedReader br = new BufferedReader(pr);

        System.out.println(br.readLine());

    }

    //可编译且可调用的引擎

    public static void test08() throws ScriptException{

        ScriptEngineManager manager = new ScriptEngineManager();

        ScriptEngine engine = manager.getEngineByName("js");

        if(engine instanceof Compilable){//判断脚本引擎是否支持编译操作

            Compilable compilable = (Compilable)engine;//用来保存编译的结果，从而能重复调用脚本而没有重复解释的开销

            //compile()方法将脚本编译成无需重新编译就能反复执行的CompiledScript容器

            CompiledScript script = compilable.compile("if(age<25){riskFactor = 1.5;}else if(noClaims){ristFactor = 0.75;}else{ristFactor = 1.0;}");

           Bindings bindings = engine.createBindings();

           bindings.put("age", 26);

           bindings.put("noClaims", Boolean.TRUE);

           bindings.put("riskFactor", 1.0);

           Object result = script.eval(bindings);//使用CompiledScript的eval()方法计算编译后的表达式

            System.out.println(result.toString());

        }

    }

   //调用脚本中的函数和方法

    public static void test09() throws ScriptException, NoSuchMethodException, FileNotFoundException{

        ScriptEngineManager manager = new ScriptEngineManager();

        ScriptEngine engine = manager.getEngineByName("js");

        engine.eval("function increment(i){return i+1;}");

        if (engine instanceof Invocable) {//判断脚本引擎是否支持编译操作

            Invocable invocable = (Invocable)engine;//Invocable允许从java代码调用定义在脚本中的单个函数

            Object result = invocable.invokeFunction("increment", new Object[]{10});// 调用脚本中定义的顶层程序和函数

            System.out.println("result = "+result);

        }

        ScriptEngine engine2 = manager.getEngineByName("js");

        engine2.eval(new FileReader("E:/ScriptEngine/test03.js"));

        if(engine2 instanceof Invocable){

            Invocable invocable = (Invocable)engine2;

            invocable.invokeMethod(engine2.get("hello"), "sayHello", "yangYong");//对以前的脚本执行中已经编译的脚本对象（以 ScriptEngine 的状态保持）调用某一方法

        }

    }

public interface Hello {

    public int increment(int value);

    public void sayHello(String name);

}

    //调用脚本中的函数和方法并将他们作为java程序中的接口实现

    public static void test10() throws FileNotFoundException, ScriptException{

        ScriptEngineManager manager = new ScriptEngineManager();

        ScriptEngine engine = manager.getEngineByName("js");

        engine.eval("function increment(i){return i+1;}");

        if (engine instanceof Invocable) {

            Invocable invocable = (Invocable)engine;

            Hello hello = invocable.getInterface(Hello.class);//返回一个接口的实现，该接口使用解释器中编译的函数

            Object result = hello.increment(2);

            System.out.println("result = "+result);

        }

        engine.eval(new FileReader("E:/ScriptEngine/test03.js"));

        if(engine instanceof Invocable){

            Invocable invocable2 = (Invocable)engine;

            Hello hello = invocable2.getInterface(engine.get("hello"), Hello.class);// 返回一个接口的实现，该接口使用解释器中已编译脚本对象的成员函数

            hello.sayHello("zhangSan");

        }

    }