How to pass model attributes from one Spring MVC controller to another controller?

I use spring 3.2.3 and here is how I solved similar problem.
1) Added RedirectAttributes redirectAttributes to the method parameter list in controller 1.

public String controlMapping1(
        @ModelAttribute("mapping1Form") final Object mapping1FormObject,
        final BindingResult mapping1BindingResult,
        final Model model, 
        final RedirectAttributes redirectAttributes)

2) Inside the method added code to add flash attribute to redirectAttributes redirectAttributes.addFlashAttribute("mapping1Form", mapping1FormObject);

3) Then, in the second contoller use method parameter annotated with @ModelAttribute to access redirect Attributes

@ModelAttribute("mapping1Form") final Object mapping1FormObject

Here is the sample code from Controller 1:

@RequestMapping(value = { "/mapping1" }, method = RequestMethod.POST)
public String controlMapping1(
        @ModelAttribute("mapping1Form") final Object mapping1FormObject,
        final BindingResult mapping1BindingResult,
        final Model model, 
        final RedirectAttributes redirectAttributes) {

    redirectAttributes.addFlashAttribute("mapping1Form", mapping1FormObject);

    return "redirect:mapping2";
}   

From Contoller 2:

@RequestMapping(value = "/mapping2", method = RequestMethod.GET)
public String controlMapping2(
        @ModelAttribute("mapping1Form") final Object mapping1FormObject,
        final BindingResult mapping1BindingResult,
        final Model model) {

    model.addAttribute("transformationForm", mapping1FormObject);

    return "new/view";  
}

Using just redirectAttributes.addFlashAttribute(...) -> "redirect:..." worked as well, didn't have to "reinsert" the model attribute.

Thanks, aborskiy!

I think that the most elegant way to do it is to implement custom Flash Scope in Spring MVC.

the main idea for the flash scope is to store data from one controller till next redirect in second controller

Please refer to my answer on the custom scope question:

Spring MVC custom scope bean

The only thing that is missing in this code is the following xml configuration:

<bean id="flashScopeInterceptor" class="com.vanilla.springMVC.scope.FlashScopeInterceptor" />
<bean id="handlerMapping" class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping">
  <property name="interceptors">
    <list><ref bean="flashScopeInterceptor"/></list>
  </property>
</bean>