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

All Methods Instance Methods Concrete Methods
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, 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(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 Detail
  - SendToMethodReturnValueHandler
```
public SendToMethodReturnValueHandler(SimpMessageSendingOperations messagingTemplate,
                                      boolean annotationRequired)
```
- Method Detail
  - 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(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()
```
    Return 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(Object returnValue,
                              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
```
protected String getUserName(Message<?> message,
                             MessageHeaders headers)
```
  - getTargetDestinations
```
protected String[] getTargetDestinations(Annotation annotation,
                                         Message<?> message,
                                         String defaultPrefix)
```
  - toString
```
public String toString()
```
    Overrides:
    toString in class Object

Class SendToMethodReturnValueHandler

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

SendToMethodReturnValueHandler

Method Detail

setDefaultDestinationPrefix

getDefaultDestinationPrefix

setDefaultUserDestinationPrefix

getDefaultUserDestinationPrefix

setHeaderInitializer

getHeaderInitializer

supportsReturnType

handleReturnValue

getUserName

getTargetDestinations

toString