Example usage for org.springframework.web.method.annotation ModelFactory getNameForParameter

Introduction

In this page you can find the example usage for org.springframework.web.method.annotation ModelFactory getNameForParameter.

Prototype

public static String getNameForParameter(MethodParameter parameter) 

Source Link

Document

Derive the model attribute name for the given method parameter based on a @ModelAttribute parameter annotation (if present) or falling back on parameter type based conventions.

Usage

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

/**
 * Resolve the argument from the model or if not found instantiate it with
 * its default if it is available. The model attribute is then populated
 * with request values via data binding and optionally validated
 * if {@code @java.validation.Valid} is present on the argument.
 * @throws BindException if data binding and validation result in an error
 * and the next method parameter is not of type {@link Errors}
 * @throws Exception if WebDataBinder initialization fails
 */// w  ww .  ja  v a  2  s .  c  om
@Override
@Nullable
public final Object resolveArgument(MethodParameter parameter, @Nullable ModelAndViewContainer mavContainer,
        NativeWebRequest webRequest, @Nullable WebDataBinderFactory binderFactory) throws Exception {

    Assert.state(mavContainer != null, "ModelAttributeMethodProcessor requires ModelAndViewContainer");
    Assert.state(binderFactory != null, "ModelAttributeMethodProcessor requires WebDataBinderFactory");

    String name = ModelFactory.getNameForParameter(parameter);
    ModelAttribute ann = parameter.getParameterAnnotation(ModelAttribute.class);
    if (ann != null) {
        mavContainer.setBinding(name, ann.binding());
    }

    Object attribute = null;
    BindingResult bindingResult = null;

    if (mavContainer.containsAttribute(name)) {
        attribute = mavContainer.getModel().get(name);
    } else {
        // Create attribute instance
        try {
            attribute = createAttribute(name, parameter, binderFactory, webRequest);
        } catch (BindException ex) {
            if (isBindExceptionRequired(parameter)) {
                // No BindingResult parameter -> fail with BindException
                throw ex;
            }
            // Otherwise, expose null/empty value and associated BindingResult
            if (parameter.getParameterType() == Optional.class) {
                attribute = Optional.empty();
            }
            bindingResult = ex.getBindingResult();
        }
    }

    if (bindingResult == null) {
        // Bean property binding and validation;
        // skipped in case of binding failure on construction.
        WebDataBinder binder = binderFactory.createBinder(webRequest, attribute, name);
        if (binder.getTarget() != null) {
            if (!mavContainer.isBindingDisabled(name)) {
                bindRequestParameters(binder, webRequest);
            }
            validateIfApplicable(binder, parameter);
            if (binder.getBindingResult().hasErrors() && isBindExceptionRequired(binder, parameter)) {
                throw new BindException(binder.getBindingResult());
            }
        }
        // Value type adaptation, also covering java.util.Optional
        if (!parameter.getParameterType().isInstance(attribute)) {
            attribute = binder.convertIfNecessary(binder.getTarget(), parameter.getParameterType(), parameter);
        }
        bindingResult = binder.getBindingResult();
    }

    // Add resolved attribute and BindingResult at the end of the model
    Map<String, Object> bindingResultModel = bindingResult.getModel();
    mavContainer.removeAttributes(bindingResultModel);
    mavContainer.addAllAttributes(bindingResultModel);

    return attribute;
}

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From source file:org.springframework.web.method.annotation.support.ModelAttributeMethodProcessor.java

/**
 * Resolve the argument from the model or if not found instantiate it with 
 * its default if it is available. The model attribute is then populated 
 * with request values via data binding and optionally validated
 * if {@code @java.validation.Valid} is present on the argument.
 * @throws BindException if data binding and validation result in an error
 * and the next method parameter is not of type {@link Errors}.
 * @throws Exception if WebDataBinder initialization fails.
 *///from ww  w .  j  a  v  a  2 s.com
public final Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer,
        NativeWebRequest request, WebDataBinderFactory binderFactory) throws Exception {
    String name = ModelFactory.getNameForParameter(parameter);
    Object target = (mavContainer.containsAttribute(name)) ? mavContainer.getModel().get(name)
            : createAttribute(name, parameter, binderFactory, request);

    WebDataBinder binder = binderFactory.createBinder(request, target, name);

    if (binder.getTarget() != null) {
        bindRequestParameters(binder, request);

        if (isValidationApplicable(binder.getTarget(), parameter)) {
            binder.validate();
        }

        if (binder.getBindingResult().hasErrors()) {
            if (isBindExceptionRequired(binder, parameter)) {
                throw new BindException(binder.getBindingResult());
            }
        }
    }

    mavContainer.addAllAttributes(binder.getBindingResult().getModel());

    return binder.getTarget();
}

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