org.springframework.web.method.support

Class HandlerMethodReturnValueHandlerComposite

java.lang.Object

org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite

All Implemented Interfaces:

AsyncHandlerMethodReturnValueHandler, HandlerMethodReturnValueHandler

public class HandlerMethodReturnValueHandlerComposite
extends java.lang.Object
implements AsyncHandlerMethodReturnValueHandler

Handles method return values by delegating to a list of registered HandlerMethodReturnValueHandlers. Previously resolved return types are cached for faster lookups.

Since:

3.1

Author:

Rossen Stoyanchev

Field Summary

Fields

Modifier and Type	Field and Description
protected Log	logger
private java.util.List<HandlerMethodReturnValueHandler>	returnValueHandlers

Constructor Summary

Constructors

Constructor and Description
HandlerMethodReturnValueHandlerComposite()

Method Summary

Modifier and Type	Method and Description
HandlerMethodReturnValueHandlerComposite	addHandler(HandlerMethodReturnValueHandler handler) Add the given HandlerMethodReturnValueHandler.
HandlerMethodReturnValueHandlerComposite	addHandlers(java.util.List<? extends HandlerMethodReturnValueHandler> handlers) Add the given HandlerMethodReturnValueHandlers.
java.util.List<HandlerMethodReturnValueHandler>	getHandlers() Return a read-only list with the registered handlers, or an empty list.
private HandlerMethodReturnValueHandler	getReturnValueHandler(MethodParameter returnType)
void	handleReturnValue(java.lang.Object returnValue, MethodParameter returnType, ModelAndViewContainer mavContainer, NativeWebRequest webRequest) Iterate over registered HandlerMethodReturnValueHandlers and invoke the one that supports it.
boolean	isAsyncReturnValue(java.lang.Object value, MethodParameter returnType) Whether the given return value represents asynchronous computation.
private HandlerMethodReturnValueHandler	selectHandler(java.lang.Object value, MethodParameter returnType)
boolean	supportsReturnType(MethodParameter returnType) Whether the given method return type is supported by any registered HandlerMethodReturnValueHandler.

Methods inherited from class java.lang.Object

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

Field Detail

logger

protected final Log logger

returnValueHandlers

private final java.util.List<HandlerMethodReturnValueHandler> returnValueHandlers

Constructor Detail

HandlerMethodReturnValueHandlerComposite

public HandlerMethodReturnValueHandlerComposite()

Method Detail

getHandlers

public java.util.List<HandlerMethodReturnValueHandler> getHandlers()

Return a read-only list with the registered handlers, or an empty list.

supportsReturnType

public boolean supportsReturnType(MethodParameter returnType)

Whether the given method return type is supported by any registered HandlerMethodReturnValueHandler.

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

getReturnValueHandler

private HandlerMethodReturnValueHandler getReturnValueHandler(MethodParameter returnType)

handleReturnValue

public void handleReturnValue(java.lang.Object returnValue,
                              MethodParameter returnType,
                              ModelAndViewContainer mavContainer,
                              NativeWebRequest webRequest)
                       throws java.lang.Exception

Iterate over registered HandlerMethodReturnValueHandlers and invoke the one that supports it.

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) which must have returned true.

mavContainer - the ModelAndViewContainer for the current request

webRequest - the current request

Throws:

java.lang.IllegalStateException - if no suitable HandlerMethodReturnValueHandler is found.

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

selectHandler

private HandlerMethodReturnValueHandler selectHandler(java.lang.Object value,
                                                      MethodParameter returnType)

isAsyncReturnValue

public boolean isAsyncReturnValue(java.lang.Object value,
                                  MethodParameter returnType)

Description copied from interface: AsyncHandlerMethodReturnValueHandler

Whether the given return value represents asynchronous computation.

Specified by:

isAsyncReturnValue in interface AsyncHandlerMethodReturnValueHandler

Parameters:

value - the return value

returnType - the return type

Returns:

true if the return value is asynchronous.

addHandler

public HandlerMethodReturnValueHandlerComposite addHandler(HandlerMethodReturnValueHandler handler)

Add the given HandlerMethodReturnValueHandler.

addHandlers

public HandlerMethodReturnValueHandlerComposite addHandlers(java.util.List<? extends HandlerMethodReturnValueHandler> handlers)

Add the given HandlerMethodReturnValueHandlers.