applet中使用jmf.jar碰到的permission denied问题

这个jar应该是orcale的java ee实现 因为没有源码 毫无头绪 就是调用到下面的代码遇到的异常Registry.set(PROP_ALLOW_CAPTURE_FROM_APPLETS, new Boolean(true));
            Registry.set(PROP_ALLOW_SAVE_FILE_FROM_APPLETS, new Boolean(true));            Registry.set(PROP_REGISTRY_AUTHOR, PROP_REGISTRY_AUTHOR_VALUE);

            try
            {
                Registry.commit();
            }
            catch (Exception exc)
            {
                logger.error(
                    "Failed to initially commit JMFRegistry. Ignoring err."
                    , exc);
            }异常：
java.lang.SecurityException: commit: Permission denied
at com.sun.media.util.Registry.commit(Registry.java:251)
at net.java.sip.communicator.impl.media.device.JmfDeviceDetector.initialize(JmfDeviceDetector.java:110)
at net.java.sip.communicator.impl.media.device.JmfDeviceDetector.setupJMF(JmfDeviceDetector.java:377)
at net.java.sip.communicator.impl.media.device.JmfDeviceDetector.detectAndConfigureCaptureDevices(JmfDeviceDetector.java:392)
at net.java.sip.communicator.impl.media.device.DeviceConfiguration.initialize(DeviceConfiguration.java:64)
at net.java.sip.communicator.impl.media.MediaServiceImpl$DeviceConfigurationThread.run(MediaServiceImpl.java:367)
at net.java.sip.communicator.impl.media.MediaServiceImpl.start(MediaServiceImpl.java:221)
at net.java.sip.communicator.impl.media.MediaActivator.start(MediaActivator.java:54)
at net.java.sip.communicator.BootLoader.initialize(BootLoader.java:49)
at net.java.sip.communicator.impl.protocol.CallManager.<init>(CallManager.java:48)
at Test.go(Test.java:97)
at Test.init(Test.java:42)
at sun.applet.AppletPanel.run(AppletPanel.java:417)
at java.lang.Thread.run(Thread.java:619)