Package 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 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 session id 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

Constructor Summary

Constructors

Constructor	Description
SendToMethodReturnValueHandler(SimpMessageSendingOperations messagingTemplate, boolean annotationRequired)

Method Summary

Modifier and Type	Method	Description
String	getDefaultDestinationPrefix()	Return the configured default destination prefix.
String	getDefaultUserDestinationPrefix()	Return the configured default user destination prefix.
MessageHeaderInitializer	getHeaderInitializer()	Return the configured header initializer.
protected String[]	getTargetDestinations(Annotation annotation, Message<?> message, String defaultPrefix)
protected String	getUserName(Message<?> message, MessageHeaders headers)
void	handleReturnValue(Object returnValue, org.springframework.core.MethodParameter returnType, Message<?> message)	Handle the given return value.
void	setDefaultDestinationPrefix(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(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(org.springframework.core.MethodParameter returnType)	Whether the given method return type is supported by this handler.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Details

SendToMethodReturnValueHandler

public SendToMethodReturnValueHandler(SimpMessageSendingOperations messagingTemplate,
 boolean annotationRequired)

Method Details

setDefaultDestinationPrefix

public void setDefaultDestinationPrefix(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 String getDefaultDestinationPrefix()

Return the configured default destination prefix.

See Also:

• setDefaultDestinationPrefix(String)

setDefaultUserDestinationPrefix

public void setDefaultUserDestinationPrefix(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 String getDefaultUserDestinationPrefix()

Return the configured default user destination prefix.

See Also:

• setDefaultUserDestinationPrefix(String)

setHeaderInitializer

public void setHeaderInitializer(@Nullable
 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

@Nullable
public MessageHeaderInitializer getHeaderInitializer()

Return the configured header initializer.

supportsReturnType

public boolean supportsReturnType(org.springframework.core.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(@Nullable
 Object returnValue,
 org.springframework.core.MethodParameter returnType,
 Message<?> message)
                       throws 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:

Exception - if the return value handling results in an error

getUserName

@Nullable
protected String getUserName(Message<?> message,
 MessageHeaders headers)

getTargetDestinations

protected String[] getTargetDestinations(@Nullable
 Annotation annotation,
 Message<?> message,
 String defaultPrefix)

toString

public String toString()

Overrides:

toString in class Object