org.joshvm.event

Class MessageHandler

java.lang.Object

org.joshvm.event.MessageHandler

public class MessageHandler
extends Object

MessageHandler is used to send messages to other applications or receive messages from other applications.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	MessageHandler.Listener Listener to handle messages from other applications.

Method Summary

Methods

Modifier and Type	Method and Description
static MessageHandler	getInstance() Get MessageHandler instance
static boolean	isValidName(String name) Check registered name is valid or not
void	register(String name) Register this application with the specified name. Must call this method before sending messages, otherwise a MessageException will be thrown out. The maximum length of name is 32, and only digit, alphabetic, '_', '-' can be used.
void	sendMessage(String target, String message) Send message to target application with specified registered name
String	sendSystemRequest(String message) Send a request to system to handle
void	setListener(MessageHandler.Listener listener) Register a callback to be invoked when receive a message.
void	unregister() Unregister this application

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getInstance

public static MessageHandler getInstance()

Get MessageHandler instance

Returns:

unique MessageHandler object

setListener

public void setListener(MessageHandler.Listener listener)

Register a callback to be invoked when receive a message.

Parameters:

listener - the Listener that will be run.

isValidName

public static boolean isValidName(String name)

Check registered name is valid or not

Parameters:

name - registered name

Returns:

true if valid, false otherwise.

register

public void register(String name)
              throws MessageException

Register this application with the specified name.
Must call this method before sending messages, otherwise a MessageException will be thrown out.

The maximum length of name is 32, and only digit, alphabetic, '_', '-' can be used.

Parameters:

name - registered name of this application. If it is null, a default name will used.

Throws:

MessageException - If failed to register

See Also:

unregister()

sendMessage

public void sendMessage(String target,
               String message)
                 throws MessageException

Send message to target application with specified registered name

Parameters:

target - registered name of target application

message - message data

Throws:

MessageException - If failed to send message. e.g. send before registered

sendSystemRequest

public String sendSystemRequest(String message)
                         throws MessageException

Send a request to system to handle

Parameters:

message - request data in json string format

Returns:

response of request if any, maybe null.

Throws:

MessageException - If failed to send request or the request is invalid.

unregister

public void unregister()

Unregister this application

See Also:

register(java.lang.String)