private HandlerMethodReturnValueHandler getReturnValueHandler(MethodParameter returnType) {
for (HandlerMethodReturnValueHandler handler : this.returnValueHandlers) {
if (handler.supportsReturnType(returnType)) {
return handler;
}
}
return null;
}
/**
* Iterate over registered {@link HandlerMethodReturnValueHandler}s and invoke the one that
* supports it.
*
* @exception IllegalStateException if no suitable {@link HandlerMethodReturnValueHandler} is
* found.
*/
public void handleReturnValue(
Object returnValue,
MethodParameter returnType,
ModelAndViewContainer mavContainer,
NativeWebRequest webRequest)
throws Exception {
HandlerMethodReturnValueHandler handler = getReturnValueHandler(returnType);
Assert.notNull(
handler, "Unknown return value type [" + returnType.getParameterType().getName() + "]");
handler.handleReturnValue(returnValue, returnType, mavContainer, webRequest);
}
@Override
public void handleReturnValue(Object returnValue, MethodParameter returnType, Message<?> message)
throws Exception {
HandlerMethodReturnValueHandler handler = getReturnValueHandler(returnType);
Assert.notNull(
handler,
"No handler for return value type [" + returnType.getParameterType().getName() + "]");
if (logger.isTraceEnabled()) {
logger.trace("Processing return value with " + handler);
}
handler.handleReturnValue(returnValue, returnType, message);
}
/**
* Find a registered {@link HandlerMethodReturnValueHandler} that supports the given return type.
*/
private HandlerMethodReturnValueHandler getReturnValueHandler(MethodParameter returnType) {
HandlerMethodReturnValueHandler result = this.returnValueHandlerCache.get(returnType);
if (result == null) {
for (HandlerMethodReturnValueHandler returnValueHandler : returnValueHandlers) {
if (logger.isTraceEnabled()) {
logger.trace(
"Testing if return value handler ["
+ returnValueHandler
+ "] supports ["
+ returnType.getGenericParameterType()
+ "]");
}
if (returnValueHandler.supportsReturnType(returnType)) {
result = returnValueHandler;
this.returnValueHandlerCache.put(returnType, returnValueHandler);
break;
}
}
}
return result;
}
