Why does my LiveConnect sockets Applet sometimes hang?

When Javascript calls a method in a Java Applet, it is running in a special context. Therefore, it must not block, (that is, 'enter' a wait state) while the system handles /O a/, or other Java thread runs. In many cases, the call may block, such as reading from a Socket (or nearly any method in the IO & net packages). Other cases are more obscure.

Possible blocking calls may include: getImage(), play(), showDocument(), INetAddress.getAddress(). Simply generating the first instance of a class can block because it may need to be loaded from the host or file system cache, e.g. new myPublicClass().

Generally, it is best to design LiveConnected Applet methods to:

This is not difficult, and it allows your Javascript to continue to react to the user while the Applet does its work.

NOTE: It would be inefficient for simple calls if this was handled automatically. Thus, every LiveConnect call requires thread rescheduling.