java 中使用v8引擎_java8 新特性 v8 nashorn 引擎（五）

简单的javascript 作为文本输出

ScriptEngineManager manager = new ScriptEngineManager();

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

String js;

js = "var map = Array.prototype.map \n";

js += "var names = [\"john\", \"jerry\", \"bob\"]\n";

js += "var a = map.call(names, function(name) { return name.length() })\n";

js += "print(a)";

try {

engine.eval(js);

} catch (ScriptException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

ScriptEngine jse = new ScriptEngineManager().getEngineByName("nashorn");

try {

jse.eval("print('Hello DoubleCloud! - inline');");

} catch (ScriptException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

执行javascript 文件

ScriptEngineManager scriptEngineManager = new ScriptEngineManager();

ScriptEngine jse = scriptEngineManager.getEngineByName("nashorn");

System.out.println("current dir: " + new File(".").getAbsoluteFile());

try {

jse.eval(new FileReader("./src/com/test/zcw/java/script.js"));

} catch (FileNotFoundException e) {

e.printStackTrace();

} catch (ScriptException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

js文件语句：eval("print('Hello DoubleCloud! - inline');")

调用javascript 函数

ScriptEngineManager scriptEngineManager = new ScriptEngineManager();

ScriptEngine jse = scriptEngineManager.getEngineByName("nashorn");

jse.eval(new FileReader("./src/com/test/zcw/java/script.js"));

Invocable runner = (Invocable) jse;

Object result = runner.invokeFunction("hi", "DoubleCloud! - via javascript function");

System.out.println(result);

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

函数内容：

var hi = function(name)

{

return 'Hi ' + name;

}

javascript调用java

var hw = Java.type('com.test.zcw.java8.JSNashorn');

var result = hw.sayHi("DoubleCloud - calling Java method in JS.");

print(result);

java

static public String sayHi(String name) {

return "Hi " + name;

}

ScriptEngineManager scriptEngineManager = new ScriptEngineManager();         ScriptEngine jse = scriptEngineManager.getEngineByName("nashorn");         jse.eval(new FileReader("./src/com/test/zcw/java/java8/script.js"));