Restrictions on what an unsigned Java applet can d

问题:

I'm trying to compile a complete list of all restrictions placed on unsigned Java applets (defined as things a normal Java application can do, but an unsigned Java applet cannot).

This is the list I've compiled so far:

An unsigned Java applet ...

1. Cannot access the local filesystem.
   • Cannot access the system clipboard.
   • Cannot initiate a print job.
   • Cannot connect to or retrieve resources from any third party server (any server other than the server the applet originated from).
   • Cannot use multicast sockets.
   • Cannot create or register a SocketImplFactory, URLStreamHandlerFactory, or ContentHandlerFactory.
   • Cannot listen to incoming socket connections.
   • Cannot listen for datagrams.
   • Cannot access some of the system properties (java.class.path, java.home, user.dir, user.home, user.name).
   • Cannot create or register a SecurityManager object.
   • Cannot dynamically load native code libraries with the load() or loadLibrary() methods of Runtime or System.
   • Cannot spawn new processes by calling any of the Runtime.exec() methods.
   • Cannot create or access threads or thread groups outside of the thread group in which the untrusted code is running.
   • Cannot define classes in java.*, sun.* and netscape.*.
   • Cannot explicitly load classes from the sun.* package.
   • Cannot exit the Java runtime by calling System.exit() or Runtime.exit().
   • Cannot access the system event queue.
   • Cannot use the java.lang.Class reflection methods to obtain information about nonpublic members of a class, unless the class was loaded from the same host as the untrusted code.
   • Cannot manipulate security identities in any way (java.security).
   • Cannot set or read security properties (java.security).
   • Cannot list, look up, insert, or remove security providers (java.security).

Question: Are there any restrictions missing? If so, please clearly state what restriction you believe is missing from the list.

回答1:

See this from Sun's tutorial: What Applets Can and Cannot Do.

回答2:

Also you cannot register an UncaughtExceptionHandler.