com.googlecode.psiprobe.controllers.sql.CachedRecordSetController.java Source code

Java tutorial

Introduction

Here is the source code for com.googlecode.psiprobe.controllers.sql.CachedRecordSetController.java

Source

/*
 * Licensed under the GPL License.  You may not use this file except in
 * compliance with the License.  You may obtain a copy of the License at
 *
 *     http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 *
 * THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */
package com.googlecode.psiprobe.controllers.sql;

import com.googlecode.psiprobe.model.sql.DataSourceTestInfo;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.springframework.web.bind.ServletRequestUtils;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.ParameterizableViewController;

/**
 * Displays a result set cached in an attribute of HttpSession object to support
 * result set pagination feature without re-executing a query that created the
 * result set.
 * 
 * @author Andy Shapoval
 */
public class CachedRecordSetController extends ParameterizableViewController {
    protected ModelAndView handleRequestInternal(HttpServletRequest request, HttpServletResponse response)
            throws Exception {
        int rowsPerPage = ServletRequestUtils.getIntParameter(request, "rowsPerPage", 0);
        List results = null;
        int rowsAffected = 0;
        HttpSession sess = request.getSession(false);

        if (sess == null) {
            request.setAttribute("errorMessage",
                    getMessageSourceAccessor().getMessage("probe.src.dataSourceTest.cachedResultSet.failure"));
            logger.error("Cannot retrieve a cached result set. Http session is NULL.");
        } else {
            DataSourceTestInfo sessData = (DataSourceTestInfo) sess
                    .getAttribute(DataSourceTestInfo.DS_TEST_SESS_ATTR);

            if (sessData == null) {
                request.setAttribute("errorMessage",
                        getMessageSourceAccessor().getMessage("probe.src.dataSourceTest.cachedResultSet.failure"));
                logger.error("Cannot retrieve a cached result set. " + DataSourceTestInfo.DS_TEST_SESS_ATTR
                        + " session attribute is NULL.");
            } else {
                synchronized (sess) {
                    sessData.setRowsPerPage(rowsPerPage);
                }

                results = sessData.getResults();

                if (results == null) {
                    request.setAttribute("errorMessage", getMessageSourceAccessor()
                            .getMessage("probe.src.dataSourceTest.cachedResultSet.failure"));
                    logger.error("Cached results set is NULL.");
                } else {
                    rowsAffected = results.size();
                }
            }
        }

        ModelAndView mv = new ModelAndView(getViewName(), "results", results);
        mv.addObject("rowsAffected", String.valueOf(rowsAffected));
        mv.addObject("rowsPerPage", String.valueOf(rowsPerPage));

        return mv;
    }
}