com.trenako.web.infrastructure.RangeRequestArgumentResolver.java Source code

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Here is the source code for com.trenako.web.infrastructure.RangeRequestArgumentResolver.java

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/*
 * Copyright 2012 the original author or authors.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.trenako.web.infrastructure;

import java.beans.PropertyEditorSupport;
import java.util.Date;

import javax.servlet.ServletRequest;

import org.apache.commons.lang3.time.DateFormatUtils;
import org.apache.commons.lang3.time.DateUtils;
import org.springframework.beans.PropertyValue;
import org.springframework.beans.PropertyValues;
import org.springframework.core.MethodParameter;
import org.springframework.data.domain.Sort;
import org.springframework.data.domain.Sort.Direction;
import org.springframework.web.bind.ServletRequestParameterPropertyValues;
import org.springframework.web.bind.WebDataBinder;
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.trenako.results.RangeRequest;
import com.trenako.results.RangeRequest.RangeTypes;

/**
 * It represents a web request resolver for {@code RangeRequest}.
 *
 * @author Carlo Micieli
 */
public class RangeRequestArgumentResolver implements HandlerMethodArgumentResolver {
    private static final Object UNRESOLVED = new Object();
    private static final RangeRequest DEFAULT_RANGE_REQUEST = new RangeRequest();
    private final RangeRequest failbackRequest;

    /**
     * Creates an empty {@code RangeRequestArgumentResolver}.
     */
    public RangeRequestArgumentResolver() {
        this(DEFAULT_RANGE_REQUEST);
    }

    /**
     * Creates a new {@code RangeRequestArgumentResolver}.
     *
     * @param failbackRequest a failback request
     */
    public RangeRequestArgumentResolver(RangeRequest failbackRequest) {
        this.failbackRequest = failbackRequest;
    }

    @Override
    public Object resolveArgument(MethodParameter param, ModelAndViewContainer mavContainer,
            NativeWebRequest webRequest, WebDataBinderFactory webBinder) throws Exception {

        if (param.getParameterType().equals(RangeRequest.class)) {

            RangeRequest rangeRequest = new RangeRequest(this.failbackRequest.getSort(),
                    this.failbackRequest.getSize(), null, null);
            ServletRequest request = (ServletRequest) webRequest.getNativeRequest();

            PropertyValues propValues = new ServletRequestParameterPropertyValues(request);

            WebDataBinder wdb = webBinder.createBinder(webRequest, rangeRequest, "");
            wdb.registerCustomEditor(Sort.class, new SortPropertyEditor(propValues));
            wdb.bind(propValues);

            if (rangeRequest.getRangeType() == RangeTypes.DATES) {
                parseSinceDate(rangeRequest);
                parseMaxDate(rangeRequest);
            }

            return rangeRequest;
        }

        return UNRESOLVED;
    }

    private void parseSinceDate(RangeRequest rangeRequest) {
        Object o = rangeRequest.getSince();
        rangeRequest.setSince(parseDate(o));
    }

    private void parseMaxDate(RangeRequest rangeRequest) {
        Object o = rangeRequest.getMax();
        rangeRequest.setMax(parseDate(o));
    }

    private Date parseDate(Object since) {
        if (since == null)
            return null;

        try {
            return DateUtils.parseDate(since.toString(), DateFormatUtils.ISO_DATETIME_FORMAT.getPattern());
        } catch (Exception e) {
            return null;
        }
    }

    @Override
    public boolean supportsParameter(MethodParameter par) {
        Class<?> paramType = par.getParameterType();
        return RangeRequest.class.isAssignableFrom(paramType);
    }

    /**
     * A {@code PropertyEditor} to process the order for the sort criteria.
     *
     * @author Carlo Micieli
     */
    private static class SortPropertyEditor extends PropertyEditorSupport {
        private final PropertyValues values;

        public SortPropertyEditor(PropertyValues values) {
            this.values = values;
        }

        @Override
        public void setAsText(String text) throws IllegalArgumentException {
            PropertyValue rawOrder = values.getPropertyValue(RangeRequest.ORDER_NAME);
            Direction order = null == rawOrder ? Direction.ASC
                    : Direction.fromString(rawOrder.getValue().toString());

            setValue(new Sort(order, text));
        }
    }
}