Example usage for org.springframework.web.method.support ModelAndViewContainer mergeAttributes

Introduction

In this page you can find the example usage for org.springframework.web.method.support ModelAndViewContainer mergeAttributes.

Prototype

public ModelAndViewContainer mergeAttributes(@Nullable Map<String, ?> attributes) 

Source Link

Document

Copy attributes in the supplied Map with existing objects of the same name taking precedence (i.e.

Usage

From source file:org.springframework.web.method.annotation.ModelFactory.java

/**
 * Populate the model in the following order:
 * <ol>/*from   w w  w.  jav  a2  s.c om*/
 * <li>Retrieve "known" session attributes listed as {@code @SessionAttributes}.
 * <li>Invoke {@code @ModelAttribute} methods
 * <li>Find {@code @ModelAttribute} method arguments also listed as
 * {@code @SessionAttributes} and ensure they're present in the model raising
 * an exception if necessary.
 * </ol>
 * @param request the current request
 * @param container a container with the model to be initialized
 * @param handlerMethod the method for which the model is initialized
 * @throws Exception may arise from {@code @ModelAttribute} methods
 */
public void initModel(NativeWebRequest request, ModelAndViewContainer container, HandlerMethod handlerMethod)
        throws Exception {

    Map<String, ?> sessionAttributes = this.sessionAttributesHandler.retrieveAttributes(request);
    container.mergeAttributes(sessionAttributes);
    invokeModelAttributeMethods(request, container);

    for (String name : findSessionAttributeArguments(handlerMethod)) {
        if (!container.containsAttribute(name)) {
            Object value = this.sessionAttributesHandler.retrieveAttribute(request, name);
            if (value == null) {
                throw new HttpSessionRequiredException("Expected session attribute '" + name + "'", name);
            }
            container.addAttribute(name, value);
        }
    }
}

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