org.springframework.messaging.simp.annotation.support

Class SendToMethodReturnValueHandler

java.lang.Object

org.springframework.messaging.simp.annotation.support.SendToMethodReturnValueHandler

All Implemented Interfaces:

HandlerMethodReturnValueHandler

public class SendToMethodReturnValueHandler
extends java.lang.Object
implements HandlerMethodReturnValueHandler

A HandlerMethodReturnValueHandler for sending to destinations specified in a SendTo or SendToUser method-level annotations.

The value returned from the method is converted, and turned to a Message and sent through the provided MessageChannel. The message is then enriched with the sessionId of the input message as well as the destination from the annotation(s). If multiple destinations are specified, a copy of the message is sent to each destination.

Since:

4.0

Author:

Rossen Stoyanchev, Sebastien Deleuze

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	SendToMethodReturnValueHandler.DestinationVariablePlaceholderResolver

Field Summary

Fields

Modifier and Type	Field and Description
private boolean	annotationRequired
private java.lang.String	defaultDestinationPrefix
private java.lang.String	defaultUserDestinationPrefix
private MessageHeaderInitializer	headerInitializer
private SimpMessageSendingOperations	messagingTemplate
private PropertyPlaceholderHelper	placeholderHelper

Constructor Summary

Constructors

Constructor and Description
SendToMethodReturnValueHandler(SimpMessageSendingOperations messagingTemplate, boolean annotationRequired)

Method Summary

Modifier and Type	Method and Description
private MessageHeaders	createHeaders(java.lang.String sessionId, MethodParameter returnType)
java.lang.String	getDefaultDestinationPrefix() Return the configured default destination prefix.
java.lang.String	getDefaultUserDestinationPrefix() Return the configured default user destination prefix.
MessageHeaderInitializer	getHeaderInitializer()
protected java.lang.String[]	getTargetDestinations(java.lang.annotation.Annotation annotation, Message<?> message, java.lang.String defaultPrefix)
protected java.lang.String	getUserName(Message<?> message, MessageHeaders headers)
void	handleReturnValue(java.lang.Object returnValue, MethodParameter returnType, Message<?> message) Handle the given return value.
private PropertyPlaceholderHelper.PlaceholderResolver	initVarResolver(MessageHeaders headers)
void	setDefaultDestinationPrefix(java.lang.String defaultDestinationPrefix) Configure a default prefix to add to message destinations in cases where a method is not annotated with @SendTo or does not specify any destinations through the annotation's value attribute.
void	setDefaultUserDestinationPrefix(java.lang.String prefix) Configure a default prefix to add to message destinations in cases where a method is annotated with @SendToUser but does not specify any destinations through the annotation's value attribute.
void	setHeaderInitializer(MessageHeaderInitializer headerInitializer) Configure a MessageHeaderInitializer to apply to the headers of all messages sent to the client outbound channel.
boolean	supportsReturnType(MethodParameter returnType) Whether the given method return type is supported by this handler.
java.lang.String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

messagingTemplate

private final SimpMessageSendingOperations messagingTemplate

annotationRequired

private final boolean annotationRequired

defaultDestinationPrefix

private java.lang.String defaultDestinationPrefix

defaultUserDestinationPrefix

private java.lang.String defaultUserDestinationPrefix

placeholderHelper

private PropertyPlaceholderHelper placeholderHelper

headerInitializer

private MessageHeaderInitializer headerInitializer

Constructor Detail

SendToMethodReturnValueHandler

public SendToMethodReturnValueHandler(SimpMessageSendingOperations messagingTemplate,
                                      boolean annotationRequired)

Method Detail

setDefaultDestinationPrefix

public void setDefaultDestinationPrefix(java.lang.String defaultDestinationPrefix)

Configure a default prefix to add to message destinations in cases where a method is not annotated with @SendTo or does not specify any destinations through the annotation's value attribute.

By default, the prefix is set to "/topic".

getDefaultDestinationPrefix

public java.lang.String getDefaultDestinationPrefix()

Return the configured default destination prefix.

See Also:

setDefaultDestinationPrefix(String)

setDefaultUserDestinationPrefix

public void setDefaultUserDestinationPrefix(java.lang.String prefix)

Configure a default prefix to add to message destinations in cases where a method is annotated with @SendToUser but does not specify any destinations through the annotation's value attribute.

By default, the prefix is set to "/queue".

getDefaultUserDestinationPrefix

public java.lang.String getDefaultUserDestinationPrefix()

Return the configured default user destination prefix.

See Also:

setDefaultUserDestinationPrefix(String)

setHeaderInitializer

public void setHeaderInitializer(MessageHeaderInitializer headerInitializer)

Configure a MessageHeaderInitializer to apply to the headers of all messages sent to the client outbound channel.

By default this property is not set.

getHeaderInitializer

public MessageHeaderInitializer getHeaderInitializer()

Returns:

the configured header initializer.

supportsReturnType

public boolean supportsReturnType(MethodParameter returnType)

Description copied from interface: HandlerMethodReturnValueHandler

Whether the given method return type is supported by this handler.

Specified by:

supportsReturnType in interface HandlerMethodReturnValueHandler

Parameters:

returnType - the method return type to check

Returns:

true if this handler supports the supplied return type; false otherwise

handleReturnValue

public void handleReturnValue(java.lang.Object returnValue,
                              MethodParameter returnType,
                              Message<?> message)
                       throws java.lang.Exception

Description copied from interface: HandlerMethodReturnValueHandler

Handle the given return value.

Specified by:

handleReturnValue in interface HandlerMethodReturnValueHandler

Parameters:

returnValue - the value returned from the handler method

returnType - the type of the return value. This type must have previously been passed to HandlerMethodReturnValueHandler.supportsReturnType(org.springframework.core.MethodParameter) and it must have returned true

message - the message that caused this method to be called

Throws:

java.lang.Exception - if the return value handling results in an error

initVarResolver

private PropertyPlaceholderHelper.PlaceholderResolver initVarResolver(MessageHeaders headers)

getUserName

protected java.lang.String getUserName(Message<?> message,
                                       MessageHeaders headers)

getTargetDestinations

protected java.lang.String[] getTargetDestinations(java.lang.annotation.Annotation annotation,
                                                   Message<?> message,
                                                   java.lang.String defaultPrefix)

createHeaders

private MessageHeaders createHeaders(java.lang.String sessionId,
                                     MethodParameter returnType)

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object