com.jwebmp.plugins.datatable.DataTablesServlet.java Source code

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Here is the source code for com.jwebmp.plugins.datatable.DataTablesServlet.java

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/*
 * Copyright (C) 2017 GedMarc
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package com.jwebmp.plugins.datatable;

import com.google.inject.Singleton;
import com.jwebmp.core.base.servlets.JWDefaultServlet;
import com.jwebmp.guicedinjection.GuiceContext;
import com.jwebmp.guicedservlets.GuicedServletKeys;
import com.jwebmp.logger.LogFactory;
import com.jwebmp.plugins.datatable.events.DataTableDataFetchEvent;
import com.jwebmp.plugins.datatable.search.DataTableSearchRequest;
import org.apache.commons.lang3.exception.ExceptionUtils;

import javax.servlet.http.HttpServletRequest;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.logging.Level;
import java.util.logging.Logger;

import static com.jwebmp.core.utilities.StaticStrings.*;

@Singleton
public class DataTablesServlet extends JWDefaultServlet {
    private static final Logger log = LogFactory.getInstance().getLogger("DataTablesServlet");

    @Override
    @SuppressWarnings("unchecked")
    public void perform() {
        HttpServletRequest request = GuiceContext.get(GuicedServletKeys.getHttpServletRequestKey());
        StringBuilder output = new StringBuilder();
        Set<Class<? extends DataTableDataFetchEvent>> allEvents = new HashSet(GuiceContext.instance()
                .getScanResult().getSubclasses(DataTableDataFetchEvent.class.getCanonicalName()).loadClasses());
        Map<String, String[]> params = request.getParameterMap();
        String className = params.get("c")[0];
        allEvents.removeIf(a -> !a.getCanonicalName().equals(className.replace(CHAR_UNDERSCORE, CHAR_DOT)));
        if (allEvents.isEmpty()) {
            writeOutput(output, HTML_HEADER_JAVASCRIPT, UTF8_CHARSET);
            DataTablesServlet.log.fine("DataTablesServlet could not find any specified data search class");
        } else {
            DataTableSearchRequest searchRequest = new DataTableSearchRequest();
            searchRequest.fromRequestMap(params);
            try {
                Class<? extends DataTableDataFetchEvent> event = allEvents.iterator().next();
                DataTableDataFetchEvent dtd = GuiceContext.get(event);
                DataTableData d = dtd.returnData(searchRequest);
                output.append(d.toString());
                writeOutput(output, HTML_HEADER_JSON, UTF8_CHARSET);
            } catch (Exception e) {
                output.append(ExceptionUtils.getStackTrace(e));
                writeOutput(output, HTML_HEADER_JAVASCRIPT, UTF8_CHARSET);
                DataTablesServlet.log.log(Level.SEVERE, "Unable to execute datatables ajax data fetch", e);
            }
        }
    }

}