biz.webgate.dominoext.poi.component.kernel.CSVProcessor.java Source code

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Here is the source code for biz.webgate.dominoext.poi.component.kernel.CSVProcessor.java

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/*
 *  Copyright WebGate Consulting AG, 2012
 * 
 * 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 biz.webgate.dominoext.poi.component.kernel;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

import javax.faces.context.FacesContext;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.csv.CSVFormat;
import org.apache.commons.csv.CSVPrinter;

import biz.webgate.dominoext.poi.utils.exceptions.POIException;
import biz.webgate.dominoext.poi.component.containers.UICSV;
import biz.webgate.dominoext.poi.component.data.csv.CSVColumn;
import biz.webgate.dominoext.poi.component.kernel.csv.EmbeddedDataSourceExportProcessor;
import biz.webgate.dominoext.poi.component.kernel.csv.XPagesDataSourceExportProcessor;
import biz.webgate.dominoext.poi.utils.logging.ErrorPageBuilder;

public class CSVProcessor {

    private static CSVProcessor m_Processor;

    private CSVProcessor() {

    }

    public static CSVProcessor getInstance() {
        if (m_Processor == null) {
            m_Processor = new CSVProcessor();
        }
        return m_Processor;
    }

    public void generateNewFile(UICSV csvDef, HttpServletResponse httpResponse, FacesContext context) {

        try {
            // First getting the File

            ByteArrayOutputStream csvBAOS = generateCSV(csvDef, context);

            httpResponse.setContentType("text/csv");
            httpResponse.setHeader("Cache-Control", "no-cache");
            httpResponse.setDateHeader("Expires", -1);
            httpResponse.setContentLength(csvBAOS.size());
            httpResponse.addHeader("Content-disposition",
                    "inline; filename=\"" + csvDef.getDownloadFileName() + "\"");
            OutputStream os = httpResponse.getOutputStream();
            csvBAOS.writeTo(os);
            os.close();
        } catch (Exception e) {
            ErrorPageBuilder.getInstance().processError(httpResponse, "Error during CSV-Generation", e);
        }

    }

    public ByteArrayOutputStream generateCSV(UICSV csvDef, FacesContext context) throws IOException, POIException {
        ByteArrayOutputStream csvBAOS = new ByteArrayOutputStream();
        OutputStreamWriter csvWriter = new OutputStreamWriter(csvBAOS);
        CSVPrinter csvPrinter = new CSVPrinter(csvWriter, CSVFormat.DEFAULT);

        List<CSVColumn> lstColumns = csvDef.getColumns();
        Collections.sort(lstColumns, new Comparator<CSVColumn>() {

            public int compare(CSVColumn o1, CSVColumn o2) {
                Integer p1 = Integer.valueOf(o1.getPosition());
                Integer p2 = Integer.valueOf(o2.getPosition());
                return p1.compareTo(p2);
            }

        });
        if (csvDef.isIncludeHeader()) {
            for (CSVColumn cl : lstColumns) {
                csvPrinter.print(cl.getTitle());
            }
            csvPrinter.println();
        }

        // DATASOURCE holen und verarbeiten.
        if (csvDef.getDataSource() != null) {
            EmbeddedDataSourceExportProcessor.getInstance().process(lstColumns, csvDef, csvPrinter, context);
        } else {
            XPagesDataSourceExportProcessor.getInstance().process(lstColumns, csvDef, csvPrinter, context);
        }

        csvPrinter.flush();
        return csvBAOS;
    }

}