Apache POI -- Java 导出Excel文档（笔记）

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;

import javax.swing.JOptionPane;

import net.evecom.fjzw.vo.report.export.AreaDeviceFlowStatistical;

import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFFont;
import org.apache.poi.hssf.usermodel.HSSFRichTextString;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.util.HSSFColor;
import org.apache.poi.hssf.util.Region;

/**
 * Excel导出通用工具类
 * 
 * @author Miles Ma
 * @version 1.0
 */
public class ExportExcelTool<T> {

    public HSSFWorkbook getWorkBook(String title, String subTitle, String[] headers, Collection<T> dataset) {
        // 创建一个工作薄和一个工作表
        HSSFWorkbook workbook = new HSSFWorkbook();
        HSSFSheet sheet = workbook.createSheet("工作表");
        sheet.setDefaultColumnWidth((short) 20);

        // 生成并设置样式
        HSSFCellStyle titleStyle = setTitleStyle(workbook);// 标题单元格样式
        HSSFFont subTitleFont = setSubTitleFont(workbook);// 子标题字体
        HSSFCellStyle headerStyle = setHeaderStyle(workbook);// 列名单元格样式
        HSSFCellStyle otherStyle = setOtherStyle(workbook);// 其他单元格样式

        // 生成报表名称
        HSSFRow titleRow = sheet.createRow(0);
        sheet.addMergedRegion(new Region(0, (short) 0, 0, (short) (headers.length - 1)));// 指定合并区域
        HSSFCell titleCell = titleRow.createCell((short) 0);
        titleRow.setHeightInPoints((short) 42);// 行高
        titleCell.setCellStyle(titleStyle);// 设置样式
        HSSFRichTextString titleText = new HSSFRichTextString(title + "\r\n" + subTitle);
        titleText.applyFont(title.length(), (title + "\r\n" + subTitle).length(), subTitleFont);
        titleCell.setCellValue(titleText);// 设置内容

        // 产生表格标题行
        HSSFRow headerRow = sheet.createRow(1);
        for (short i = 0; i < headers.length; i++) {
            HSSFCell cell = headerRow.createCell(i);
            cell.setCellStyle(headerStyle);
            HSSFRichTextString headerText = new HSSFRichTextString(headers[i]);
            cell.setCellValue(headerText);
        }
        HSSFRow dataRow = null;
        // 遍历集合数据，产生数据行
        Iterator<T> it = dataset.iterator();
        int index = 1;// 从第三行开始
        while (it.hasNext()) {
            index++;
            dataRow = sheet.createRow(index);
            T t = (T) it.next();
            // 利用反射，根据JavaBean属性的先后顺序，动态调用getXxx()方法得到属性值
            Field[] fields = t.getClass().getDeclaredFields();
            for (short i = 0; i < fields.length; i++) {
                HSSFCell cell = dataRow.createCell(i);
                cell.setCellStyle(otherStyle);
                Field field = fields[i];
                String fieldName = field.getName();
                String getMethodName = "get" + fieldName.substring(0, 1).toUpperCase() + fieldName.substring(1);
                try {
                    Method getMethod = t.getClass().getMethod(getMethodName, new Class[] {});
                    Object value = getMethod.invoke(t, new Object[] {});
                    String textValue = null;
                    if (value != null) {
                        if (value instanceof Double) {// 判断值的类型后进行强制类型转换
                            double doubleValue = (Double) value;
                            cell.setCellValue(doubleValue);
                        } else {
                            textValue = value.toString();// 其它数据类型都当作字符串简单处理
                        }
                        if (textValue != null) {
                            HSSFRichTextString richString = new HSSFRichTextString(textValue);
                            cell.setCellValue(richString);
                        }
                    }
                } catch (SecurityException e) {
                    e.printStackTrace();
                } catch (NoSuchMethodException e) {
                    e.printStackTrace();
                } catch (IllegalArgumentException e) {
                    e.printStackTrace();
                } catch (IllegalAccessException e) {
                    e.printStackTrace();
                } catch (InvocationTargetException e) {
                    e.printStackTrace();
                } finally {
                    // 清理资源
                }
            }
        }
        return workbook;
    }

    // 标题单元格样式
    private HSSFCellStyle setTitleStyle(HSSFWorkbook workbook) {
        HSSFCellStyle style = workbook.createCellStyle();
        // 字体
        HSSFFont font = workbook.createFont();
        font.setFontName("宋体");// 字体名称
        font.setFontHeightInPoints((short) 18);// 字体大小
        font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);// 加粗
        style.setFont(font);
        // 样式
        style.setWrapText(true);// 自动换行
        style.setFillForegroundColor(HSSFColor.SKY_BLUE.index);
        style.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
        style.setBorderRight(HSSFCellStyle.BORDER_THIN);
        style.setAlignment(HSSFCellStyle.ALIGN_CENTER);
        style.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);
        return style;
    }

    // 子标题字体
    private HSSFFont setSubTitleFont(HSSFWorkbook workbook) {
        HSSFFont font = workbook.createFont();
        font.setFontName("Times New Roman");// 字体名称
        font.setFontHeightInPoints((short) 14);// 字体大小
        return font;
    }

    // 列名单元格样式
    private HSSFCellStyle setHeaderStyle(HSSFWorkbook workbook) {
        HSSFCellStyle style = workbook.createCellStyle();
        // 字体
        HSSFFont font = workbook.createFont();
        font.setFontName("Times New Roman");// 字体名称
        font.setFontHeightInPoints((short) 11);// 字体大小
        font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);// 加粗
        style.setFont(font);
        // 样式
        style.setFillForegroundColor(HSSFColor.YELLOW.index);
        style.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
        style.setBorderBottom(HSSFCellStyle.BORDER_THIN);
        style.setBorderLeft(HSSFCellStyle.BORDER_THIN);
        style.setBorderRight(HSSFCellStyle.BORDER_THIN);
        style.setBorderTop(HSSFCellStyle.BORDER_THIN);
        style.setAlignment(HSSFCellStyle.ALIGN_CENTER);
        style.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);
        return style;
    }

    // 其他单元格样式
    private HSSFCellStyle setOtherStyle(HSSFWorkbook workbook) {
        HSSFCellStyle style = workbook.createCellStyle();
        // 字体
        HSSFFont font = workbook.createFont();
        font.setFontName("Times New Roman");// 字体名称
        font.setFontHeightInPoints((short) 11);// 字体大小
        style.setFont(font);
        // 样式
        style.setBorderBottom(HSSFCellStyle.BORDER_THIN);
        style.setBorderLeft(HSSFCellStyle.BORDER_THIN);
        style.setBorderRight(HSSFCellStyle.BORDER_THIN);
        style.setBorderTop(HSSFCellStyle.BORDER_THIN);
        style.setAlignment(HSSFCellStyle.ALIGN_CENTER);
        style.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);
        return style;
    }

    public static void main(String[] args) {
        ExportExcelTool<AreaDeviceFlowStatistical> tool = new ExportExcelTool<AreaDeviceFlowStatistical>();
        String[] headers = { "区域名称", "设备名称", "主机名", "总流入流量", "总流出流量", "平均流入流量", "平均流出流量", "最大流入流量", "最大流出流量" };
        List<AreaDeviceFlowStatistical> dataset = new ArrayList<AreaDeviceFlowStatistical>();
        // dataset.add(new AreaDeviceFlowStatistical("福州市", "", "10.1.6.21",
        // null, 25.21, 25.21, 25.21, 25.21, 25.21));
        // dataset.add(new AreaDeviceFlowStatistical("厦门市", "李四", "10.1.6.23",
        // 25.23, 25.23, 25.23, 25.23, 25.23, 25.23));
        // dataset.add(new AreaDeviceFlowStatistical("泉州市", "王五", "10.1.6.25",
        // 25.25, 25.25, 25.25, 25.25, 25.25, 25.25));
        OutputStream out = null;
        try {
            out = new FileOutputStream("E://流量.xls");
            String title = "省级设备流量报表";
            String subTitle = "2015年12月1日-2015年12月31日";
            HSSFWorkbook workBook = tool.getWorkBook(title, subTitle, headers, dataset);
            try {
                workBook.write(out);// 将workBook写入输出流
            } catch (IOException e) {
                e.printStackTrace();
            }
            try {
                out.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        JOptionPane.showMessageDialog(null, "导出成功!");
        System.out.println("excel导出成功！");
    }

}

/**
 * 导出Excel文件
 * 
 * @author Miles Ma
 * @version 1.0
 */
public class ExportExcelAction extends DispatchAction {

    /** 日志 */
    Logger log = Logger.getLogger(this.getClass());
    /** NodeDao */
    private NodeDao nodeDao = ConfigurationDaoFactory.getNodeDao();
    /** InterfaceDao */
    private InterfaceDao interfaceDao = ConfigurationDaoFactory.getInterfaceDao();
    /** 日期格式 */
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

    public ActionForward exportCityFlow(ActionMapping mapping, ActionForm form, HttpServletRequest request,
            HttpServletResponse response) {
        String startTime = RequestUtils.getStringParameter(request, "startTime_export", null);
        String endTime = RequestUtils.getStringParameter(request, "endTime_export", null);
        List<AreaDeviceFlowStatistical> resultlist = new ArrayList<AreaDeviceFlowStatistical>();
        try {
            if (startTime == null || endTime == null) {
                endTime = sdf.format(new Date());
                startTime = sdf.format(new Date(System.currentTimeMillis() - (86400000 * 7)));
            }
            StringBuilder nodeSql = new StringBuilder();
            nodeSql.append(" select r.* from ( ");
            nodeSql.append(" select n.*, g.name area_name ");
            nodeSql.append(" from sv_nodes n left join sv_groups g on n.area_id = g.id ");
            nodeSql.append(" where g.parent_id = 1 or g.name like ‘%平潭%‘ ");
            nodeSql.append(" ) r where r.node_type = 1 ");
            nodeSql.append(" order by r.area_id ");
            List<VoNode> nodeList = nodeDao.getNodesByNativeSql(nodeSql.toString());
            List<NodeInterface> ifList = new ArrayList<NodeInterface>();
            AreaDeviceFlowStatistical deviceFlow = null;
            String snmpifalias = null;
            for (int i = 0; i < nodeList.size(); i++) {
                snmpifalias = "";// 重置
                deviceFlow = new AreaDeviceFlowStatistical();
                String ifSql = " select * from sv_node_interfaces where up_linked = 1 and node_id = "
                        + nodeList.get(i).getId() + " order by ifnumber ";
                ifList = interfaceDao.getIfByNativeSql(ifSql);
                for (int j = 0; j < (ifList.size() - 1); j++) {
                    snmpifalias += ("‘" + ifList.get(j).getSnmpIfalias() + "‘") + ",";
                }
                if (ifList.size() > 0) {
                    snmpifalias += "‘" + ifList.get(ifList.size() - 1).getSnmpIfalias() + "‘";
                }
                FjzwReportMgr reportMgr = new FjzwReportMgr();
                Map<String, Double> nodeTraffic = reportMgr.getTotalNodeTraffic(nodeList.get(i).getId(), snmpifalias,
                        ifList.size(), FormatUtil.parseDate(startTime), FormatUtil.parseDate(endTime));
                deviceFlow.setAreaName(nodeList.get(i).getAreaName());
                deviceFlow.setDeviceName(nodeList.get(i).getNodeName());
                deviceFlow.setHostName(nodeList.get(i).getIpHostName());
                deviceFlow.setTotalNodeInOctet(nodeTraffic.get("IFINOCTET"));
                deviceFlow.setTotalNodeOutOctet(nodeTraffic.get("IFOUTOCTET"));
                deviceFlow.setAvgNodeInOctet(nodeTraffic.get("AVG_IFINOCTET"));
                deviceFlow.setAvgNodeOutOctet(nodeTraffic.get("AVG_IFOUTOCTET"));
                deviceFlow.setMaxNodeInOctet(nodeTraffic.get("MAX_IFINOCTET"));
                deviceFlow.setMaxNodeOutOctet(nodeTraffic.get("MAX_IFOUTOCTET"));
                resultlist.add(deviceFlow);
            }
        } catch (Exception e) {
            log.error("export excel error !", e);
            request.setAttribute("message", "对不起，没有获取任何有效的采样数据");
            return mapping.findForward("errMsg");
        }
        /** 将设置好的workBook对象写入输出流（生成Excel文档） */
        ExportExcelTool<AreaDeviceFlowStatistical> tool = new ExportExcelTool<AreaDeviceFlowStatistical>();
        String title = "市级设备流量统计报表";
        String startYear = startTime.split(" ")[0].split("-")[0];
        String startMonth = startTime.split(" ")[0].split("-")[1];
        String startDay = startTime.split(" ")[0].split("-")[2];
        String endYear = endTime.split(" ")[0].split("-")[0];
        String endMonth = endTime.split(" ")[0].split("-")[1];
        String endDay = endTime.split(" ")[0].split("-")[2];
        String subTitle = startYear + "年" + startMonth + "月" + startDay + "日" + "-" + endYear + "年" + endMonth + "月"
                + endDay + "日";
        String[] headers = { "区域名称", "设备名称", "主机名", "总流入流量(bit)", "总流出流量(bit)", "平均流入流量(bit/s)", "平均流出流量(bit/s)",
                "最大流入流量(bit/s)", "最大流出流量(bit/s)" };
        HSSFWorkbook workBook = tool.getWorkBook(title, subTitle, headers, resultlist);
        OutputStream out = null;
        String fileName = "市级设备流量统计报表.xls";
        String filePath = request.getSession().getServletContext().getRealPath("/") + fileName;
        try {// 新建文件输出流
            out = new FileOutputStream(filePath);
            try {// 将workBook对象写入文件输出流
                workBook.write(out);
            } catch (IOException e) {
                e.printStackTrace();
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } finally {
            try {
                out.close();// 写入后关闭文件输出流
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        /** 下载Excel文档 */
        this.setResponseHeader(response, fileName);// 设置响应头和文件名称
        OutputStream output = null;
        FileInputStream fis = null;
        try {
            output = response.getOutputStream();// 获取相应输出流
            fis = new FileInputStream(filePath);// 创建文件输入流
            byte[] b = new byte[2048];
            int i = 0;
            try {
                while ((i = fis.read(b)) > 0) {
                    output.write(b, 0, i);// 将输入流的内容写入输出流
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {// 关闭流
            try {
                output.flush();// 强制将输出流中的内容写入到文件中并且清空输出流中的内容
                fis.close();
                output.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return null;
    }

    /** 设置响应头 */
    public void setResponseHeader(HttpServletResponse response, String fileName) {
        try {
            try {
                fileName = new String(fileName.getBytes(), "ISO8859-1");
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            }
            response.setContentType("application/octet-stream;charset=ISO8859-1");
            response.setHeader("Content-Disposition", "attachment;filename=" + fileName);
            response.addHeader("Pargam", "no-cache");
            response.addHeader("Cache-Control", "no-cache");
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }
}