从Javascript调用Applet方法

Question

我有一个applet，可以从特定的文件夹上载一些文件并删除它们，但是当我从javascript代码中调用applet函数时，出现了问题，当我从init()它调用该函数时，它工作正常。

我的小程序代码：

public class Uploader extends Applet {
   String serverPath;
   String clientPath;
   private JSObject win;
   @Override
   public void init() {
       serverPath = getParameter("serverPath");
       clientPath = getParameter("clientPath");
       try {
           win = JSObject.getWindow(this);
       } catch (JSException e) {
           log.warning("Can't access JSObject object");
       }
       upload(topic,clientPath);
   }
   public void upload(String topic,String clientPath) {
       log.log(Level.SEVERE, "upload functiond");
       DefaultHttpClient client = new DefaultHttpClient();
       MultipartEntity form = new MultipartEntity();
       log.log(Level.SEVERE, "upload functiond2");
       try {
            File directory = new File(clientPath);
            log.log(Level.SEVERE, "upload functiond2.2");
            File[] files = directory.listFiles();
            log.log(Level.SEVERE, "upload functiond2.5");
            int i = 0;
            for (File file : files) {
                log.log(Level.SEVERE, "upload functiond2.6");
                i++;
                form.addPart("file" + String.valueOf(i), new FileBody(file));
                System.out.println("adding file " + String.valueOf(i) + " " + file);
                log.log(Level.SEVERE, "adding file " + String.valueOf(i) + " " + file);
            }
            log.log(Level.SEVERE, "upload functiond3");
            form.addPart("topic", new StringBody(topic, Charset.forName("UTF-8")));
            form.addPart("action", new StringBody(action, Charset.forName("UTF-8")));
            form.addPart("path", new StringBody(serverPath, Charset.forName("UTF-8")));
            HttpPost post = new HttpPost(serverPath);
      ....

这是我的JavaScript代码：

document.applet.upload(title,"c:\scan");

当我从javascript调用时，仅打印日志：

log.log(Level.SEVERE, "upload functiond2.2");

请注意，当我从initapplet方法调用时，它可以正常工作。

我将代码包装到中PriviligedAction，但仅前进了一步，然后继续

log.log(Level.SEVERE, "upload functiond2.5");

Answer 1

Java和JS的交互使安全性复杂化。JRE无法信任JS，因此它决定包括您的代码在内的整个“操作链”都是不受信任的。有一种解决方法。

需要将代码包装在中，PrivilegedAction然后使用that
的AccessController方法之一进行调用doPrivileged(..)。查看AccessController文档顶部。（方法上方）以查看示例用法。