com.runwaysdk.dataaccess.io.ExcelExporter.java Source code

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Here is the source code for com.runwaysdk.dataaccess.io.ExcelExporter.java

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/**
 * Copyright (c) 2015 TerraFrame, Inc. All rights reserved.
 *
 * This file is part of Runway SDK(tm).
 *
 * Runway SDK(tm) is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * Runway SDK(tm) 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with Runway SDK(tm).  If not, see <http://www.gnu.org/licenses/>.
 */
package com.runwaysdk.dataaccess.io;

import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.LinkedList;
import java.util.List;

import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.CellStyle;
import org.apache.poi.ss.usermodel.Font;
import org.apache.poi.ss.usermodel.Workbook;

import com.runwaysdk.SystemException;

/**
 * Exports an excel template that can later be imported with {@link ExcelImporter}. The first cell bears the name of the fully qualified type to import. Each cell in the second row much holds the name
 * of an attribute on that type (or struct.attributeName). The third row shows the display label for the attribute in that column. Actual data starts with the fourth row.
 * 
 * @author Eric
 */
public class ExcelExporter {
    /**
     * List of registered listeners for this exporter.
     */
    private List<ExcelExportListener> listeners;

    /**
     * The in memory representation of the xls file
     */
    private Workbook workbook;

    private CellStyle boldStyle = null;

    private List<ExcelExportSheet> sheets;

    /**
     * Simple constructor that sets up the workbook
     */
    public ExcelExporter() {
        this(new HSSFWorkbook());
    }

    /**
     * Simple constructor that sets up the workbook
     */
    public ExcelExporter(Workbook workbook) {
        this.workbook = workbook;
        this.listeners = new LinkedList<ExcelExportListener>();
        this.sheets = new LinkedList<ExcelExportSheet>();

        Font font = workbook.createFont();
        font.setBoldweight(Font.BOLDWEIGHT_BOLD);

        this.boldStyle = workbook.createCellStyle();
        this.boldStyle.setFont(font);
    }

    public ExcelExportSheet addTemplate(String type) {
        return this.addTemplate(type, listeners);
    }

    public ExcelExportSheet addTemplate(String type, List<ExcelExportListener> listeners) {
        ExcelExportSheet sheet = new ExcelExportSheet(listeners);
        sheet.addTemplate(type);

        this.addSheet(sheet);

        return sheet;
    }

    public void addSheet(ExcelExportSheet sheet) {
        this.sheets.add(sheet);
    }

    /**
     * Adds the given listener to this Exporter
     * 
     * @param listener
     */
    public void addListener(ExcelExportListener listener) {
        listeners.add(listener);
    }

    public List<ExcelExportListener> getListeners() {
        return listeners;
    }

    /**
     * Writes the workbook to a byte array, which can then be written to the filesystem or streamed across the net.
     * 
     * @return
     */
    public byte[] write() {
        ByteArrayOutputStream bytes = new ByteArrayOutputStream();
        BufferedOutputStream buffer = new BufferedOutputStream(bytes);

        try {
            this.write(buffer);
        } finally {
            try {
                buffer.flush();
                buffer.close();
            } catch (IOException e) {
                throw new FileWriteException(null, e);
            }
        }

        return bytes.toByteArray();
    }

    public void write(OutputStream stream) {
        for (ExcelExportSheet sheet : sheets) {
            sheet.createSheet(workbook, boldStyle);
        }

        // Notify the listeners
        for (ExcelExportListener listener : listeners) {
            listener.preWrite(workbook);
        }

        try {
            workbook.write(stream);
        } catch (IOException e) {
            throw new SystemException(e);
        }
    }
}