plum.mvc.PageArgumentResolver.java Source code

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Here is the source code for plum.mvc.PageArgumentResolver.java

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/*
 * Copyright (c) 2012-2013, Poplar Yfyang ?? (poplar1123@gmail.com).
 *
 * 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 plum.mvc;

import java.util.List;
import java.util.Map;

import org.apache.commons.collections.map.CaseInsensitiveMap;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.core.MethodParameter;
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 plum.mvc.annotation.PaginationParam;
import plum.utils.page.PageQuery;
import plum.utils.page.SortInfo;

/**
 * ???Bootstrap DataTables
 * grid??pagesize?pageindex?order?sort??PaginationCriteria
 * ?Spring-MVC??jstd-samples->servlet-context.xml?
 * <p/>
 * 
 * <pre>
 * &lt;mvc:annotation-driven>
 *     &lt;mvc:argument-resolvers>
 *     &lt;bean class="plum.mvc.PageArgumentResolver"/>
 *     &lt;/mvc:argument-resolvers>
 *    &lt;/mvc:annotation-driven>
 * </pre>
 *
 * @author poplar.yfyang
 * @version 1.0 2013-01-01 9:59 PM
 * @since JDK 1.5
 */
public class PageArgumentResolver implements HandlerMethodArgumentResolver {

    /** Logger that is available to subclasses */
    private static final Log logger = LogFactory.getLog(PageArgumentResolver.class);

    @Override
    public boolean supportsParameter(MethodParameter parameter) {
        return parameter.getParameterAnnotation(PaginationParam.class) != null;
    }

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

        final PaginationParam attr = parameter.getParameterAnnotation(PaginationParam.class);

        final Map<String, String[]> params = webRequest.getParameterMap();
        //?KEY?
        final Map<String, String[]> case_params = new CaseInsensitiveMap(params);
        String sPageIndex = case_params.get(attr.indexName())[0];
        String sPageSize = case_params.get(attr.sizeName())[0];
        //like sore=column desc,column2 asc
        String sort = case_params.get(attr.sortName())[0];

        final PageQuery pageQuery = new PageQuery();
        int pageSize;
        int pageIndex;
        try {
            pageIndex = Integer.valueOf(sPageIndex);
            pageSize = Integer.valueOf(sPageSize);
        } catch (NumberFormatException e) {
            logger.error("number paging is error!", e);
            if (!attr.required()) {
                return null;
            }
            pageSize = attr.pageSize();
            pageIndex = 0;
        } finally {
            try {
                case_params.clear();
            } catch (UnsupportedOperationException e) {
                logger.warn("param is not clear!");
            }
        }
        final List<SortInfo> sortFields = SortInfo.parseSortColumns(sort);

        pageQuery.setPageSize(pageSize);
        pageQuery.setSortInfoList(sortFields);
        pageQuery.setPage((pageIndex - 1) * pageSize);

        return pageQuery;

    }
}