如何从小程序显示 JFrame？

Question

我有一个名为 PollFrame 的类，它在名为 PollFrame.java 的文件中扩展 JFrame 。 PollFrame 包含一个表单。我有一个小程序，里面有一个按钮。单击按钮时，我希望显示 PollFrame。我将 ActionPerformed 设置为：

Pollframe poll = new PollFrame(); // This initializes the form
poll.setVisible(true);

但是，当我单击按钮时，出现以下错误：

Exception in thread "AWT-EventQueue-2" java.security.AccessControlException: access denied (java.lang.RuntimePermission exitVM.0)
    at java.security.AccessControlContext.checkPermission(Unknown Source)
    at java.security.AccessController.checkPermission(Unknown Source)
    at java.lang.SecurityManager.checkPermission(Unknown Source)
    at java.lang.SecurityManager.checkExit(Unknown Source)
    at javax.swing.JFrame.setDefaultCloseOperation(Unknown Source)
    at com.org.pollFrame.initComponents(pollFrame.java:54)
    at com.org.pollFrame.<init>(pollFrame.java:11)
    at com.org.EmployeeApplet.requestRoomActionPerformed(EmployeeApplet.java:216)
    at com.org.EmployeeApplet.access$300(EmployeeApplet.java:7)
    at com.org.EmployeeApplet$4.actionPerformed(EmployeeApplet.java:71)
    at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
    at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
    at java.awt.Component.processMouseEvent(Unknown Source)
    at javax.swing.JComponent.processMouseEvent(Unknown Source)
    at java.awt.Component.processEvent(Unknown Source)
    at java.awt.Container.processEvent(Unknown Source)
    at java.awt.Component.dispatchEventImpl(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
    at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
    at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.EventQueue.dispatchEvent(Unknown Source)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.run(Unknown Source)

我从上面的错误猜测禁止从小程序调用另一个类文件。有什么方法可以从小程序中显示 PollFrame 吗？

Answer 1

看起来您正在 JFrame 上调用 setDefaultCloseOperation() ，这会引发安全异常

您可以明确地从小程序调用另一个类，但某些操作受到限制，例如。您无法打开本地文件，打开与其他计算机的连接......

Answer 2

我有一个名为 PollFrame 的类，它在名为 PollFrame.java 的文件中扩展了 JFrame 。 PollFrame 包含一个表单。我有一个小程序，里面有一个按钮。单击按钮时，我希望显示 PollFrame。

这是一个单行代码：

applet.showDocument("PollFrame.jnlp", "_blank");

由 PollFrame.jnlp 启动的框架将能够在仍处于沙盒状态时调用它喜欢的任何默认关闭操作，因为它将有一个单独的虚拟机。为了“始终处于领先地位”，它需要受到信任（然后与所有其他旨在始终处于领先地位的应用程序展开竞争）。