com.nec.harvest.resolver.AuthenticatedArgumentResolver.java Source code

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Here is the source code for com.nec.harvest.resolver.AuthenticatedArgumentResolver.java

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/**
 * Copyright(C) 2014
 * NEC Corporation All rights reserved.
 * 
 * No permission to use, copy, modify and distribute this software
 * and its documentation for any purpose is granted.
 * This software is provided under applicable license agreement only.
 */
package com.nec.harvest.resolver;

import java.lang.annotation.Annotation;

import org.springframework.core.MethodParameter;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.web.bind.support.WebDataBinderFactory;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.method.support.ModelAndViewContainer;

import com.nec.harvest.stereotype.UserPrincipal;
import com.nec.harvest.userdetails.AuthenticatedUserDetails;

/**
 * Allows resolving the {@link com.nec.harvest.model.User} using the
 * {@link com.nec.harvest.stereotype.UserPrincipal} annotation. 
 * For example, the following {@link org.springframework.stereotype.Controller}:
 * 
 * <pre>
 * @Controller
 * public class MyController {
 *     @RequestMapping("/user/authen/show")
 *     public String show(@UserPrincipal User user) {
 *         return "view";
 *     }
 * </pre>
 * 
 * <p>
 * Will resolve the User argument using {@link com.nec.harvest.model.User}
 * from the {@link javax.servlet.http.HttpSession} if the person is an
 * attribute, else will use the
 * {@link org.springframework.security.core.context.SecurityContextHolder} to
 * get the information to retrieve the user from the
 * {@link com.nec.harvest.service.UserService}. If the
 * {@link org.springframework.security.core.Authentication} or
 * {@link org.springframework.security.core.Authentication#getPrincipal()} is
 * null, it will return null.
 * </p>
 * 
 * @author <a href="mailto:sondn@nec.vn">Ngoc Son Dang</a>
 * @version AuthenticatedArgumentResolver.java
 * @since 2014/05/21
 * 
 */
public final class AuthenticatedArgumentResolver implements HandlerMethodArgumentResolver {

    @Override
    public boolean supportsParameter(MethodParameter parameter) {
        return findMethodAnnotation(UserPrincipal.class, parameter) != null;
    }

    @Override
    public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer,
            NativeWebRequest webRequest, WebDataBinderFactory binderFactory) throws Exception {
        return AuthenticatedUserDetails.getUserPrincipal();
    }

    /**
     * Obtains the specified {@link java.lang.annotation.Annotation} on the specified {@link org.springframework.core.MethodParameter}.
     *
     * @param annotationClass the class of the {@link java.lang.annotation.Annotation} to find on the {@link org.springframework.core.MethodParameter}
     * @param parameter the {@link org.springframework.core.MethodParameter} to search for an {@link java.lang.annotation.Annotation}
     * @return the {@link java.lang.annotation.Annotation} that was found or null.
     */
    private <T extends Annotation> T findMethodAnnotation(Class<T> annotationClass, MethodParameter parameter) {
        T annotation = parameter.getParameterAnnotation(annotationClass);
        if (annotation != null) {
            return annotation;
        }

        Annotation[] annotationsToSearch = parameter.getParameterAnnotations();
        for (Annotation toSearch : annotationsToSearch) {
            annotation = AnnotationUtils.findAnnotation(toSearch.annotationType(), annotationClass);
            if (annotation != null) {
                return annotation;
            }
        }
        return null;
    }
}