从java代码调用外部javascript函数

Question

通过使用Java Scripting API,我可以在Java中执行JavaScript.但是,有人可以解释我需要添加到此代码中的内容,以便能够调用C中的函数:/Scripts/Jsfunctions.js

import javax.script.*;

public class InvokeScriptFunction {
public static void main(String[] args) throws Exception {
    ScriptEngineManager manager = new ScriptEngineManager();
    ScriptEngine engine = manager.getEngineByName("JavaScript");

    // JavaScript code in a String
    String script1 = (String)"function hello(name) {print ('Hello, ' + name);}";
    String script2 = (String)"function getValue(a,b) { if (a===\"Number\") return 1; 
                     else return b;}";
    // evaluate script
    engine.eval(script1);
    engine.eval(script2);

    Invocable inv = (Invocable) engine;

    inv.invokeFunction("hello", "Scripting!!" );  //This one works.      
 }
}

Answer 1

使用ScriptEngine.eval(java.io.Reader)读剧本

ScriptEngineManager manager = new ScriptEngineManager();
ScriptEngine engine = manager.getEngineByName("JavaScript");
// read script file
engine.eval(Files.newBufferedReader(Paths.get("C:/Scripts/Jsfunctions.js"), StandardCharsets.UTF_8));

Invocable inv = (Invocable) engine;
// call function from script file
inv.invokeFunction("yourFunction", "param");