java调用javascript文件方法

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;

import javax.script.Invocable;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;

// javascript:void(0)
public class JsInServer
{
    
    public static void main(String[]arg)throws IOException
    {
        // 得到一个ScriptEngine对象
        ScriptEngineManager maneger = new ScriptEngineManager();
        ScriptEngine engine = maneger.getEngineByName("JavaScript");
        
        // 读js文件
        String jsFile = "F:\\工作\\tmp\\pp_index_dl.js";
        FileInputStream fileInputStream = new FileInputStream(new File(jsFile));
        Reader scriptReader = new InputStreamReader(fileInputStream, "utf-8");
        
        try
        {
            engine.eval（scriptReader);
            if (engine instanceof Invocable)
            {
                // 调用JS方法
                Invocable invocable = (Invocable)engine;
                String result = (String)invocable.invokeFunction("getPass", new Object[]{"123456"});
                System.out.println(result);
                System.out.println(result.length());
            }
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
        finally
        {
            scriptReader.close();
        }
    }
}