Using the Bus across Threads and Sub Processes

SimpleBus

SimpleBus is the simple base interface for the bus that most processes that use the bus are based on.

Return Type	Method Name	Parameters	Description
SimpleBus	put	(String key, String value)	This is similar to how put works on a Map. It puts a value on the bus for the matching key. After it has been put on the bus other threads and processes can access the value.
String	get	(String key)	Allows a thread or process to wait for a value to be put on the bus that matches the inputted key. Once it arrives on the bus the value is returned.
SimpleBus	onMsg	(String key, Consumer<String> action)	Performs the action inputted as a parameter once the value matching the inputted key arrives on the bus. You would use onMsg over get when you want to do something asynchronous with a value from the bus.
boolean	hasKey	(String key)	Returns true if the key inputted currently has a value on the bus.
Bus	forUser	(String user)	This is used if you only want a specific user to look at the value placed on the bus.
String	peek	(String key)	It returns the value from the key inputted if it currently exists on the bus. If there is no value then null is returned. Unlike get it does not wait for a value to be put on the bus.

UserBus

UserBus has a similar interface to SimpleBus The main difference is that on the UserBus, the message you put and get from the bus is specific to a particular user. Within the UserBus interface, there is a String user() method which returns the name given to the user of the bus.

EventBus

EventBus is a more generic version of the SimpleBus, allowing us to no longer be restricted to just using strings on the bus. Oher then having a generic object type for the method, the rest of the interface is the same as SimpleBus. It also improves the SimpleBus by allowing you to have type safe key-value pairs.