使用poi导出execl

使用poi需要用到的jar包

本文的导出基于execl的模板导出，在大部分表头固定而格式花样比较复杂的建议使用本文介绍的方法（表头固定，只需要填充值）

1、在webroot目录下新建report文件夹来存放模板execl文件

2、jsp前台请求对应的action代码

String path = request.getSession().getServletContext().getRealPath("/")+"report/goodslaunch.xls";
String id = request.getParameter("id");//需要导出的数据的某Id
String name = this.xxService.loadNameById(id);//查询出id对应的真实名称

ByteArrayOutputStream os = (ByteArrayOutputStream)this.xxxService.expExecl(id, path);
if(null!=os && os.size()>0){
    byte[] buffer = os.toByteArray();

    String fileName = "[" + name + "]XX模块." + path.substring(path.lastIndexOf(".")+1, path.length());
    // 设置response的Header
    response.setContentType("application/x-msdownload; charset=UTF-8");
    response.addHeader("content-type", "application/x-msexcel");
    response.addHeader("content-disposition", "attachment; filename="+ new String(fileName.getBytes("gb2312"), "iso8859-1"));  //这里必须转码，或者会有问题
    response.setContentLength(buffer.length);  

    OutputStream out = response.getOutputStream();
    out.write(buffer);
    out.flush();
    os.close();
}

3、service代码

import org.apache.poi.ss.usermodel.CellStyle;
import org.apache.poi.ss.usermodel.Font;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.ss.usermodel.WorkbookFactory;

/**
 * 导出生成execl
 * @throws Exception
 */
public OutputStream expExecl(String id,String execlPath) throws Exception{
    List<XxDto> data = this.getSearchResult(id);

    Workbook wb = WorkbookFactory.create(new File(execlPath));

    Font font = wb.createFont();
    font.setFontName("微软雅黑");
    font.setFontHeightInPoints((short) 10);

    CellStyle style = wb.createCellStyle();
    style.setBorderBottom((short)1);
    style.setBorderLeft((short)1);
    style.setBorderRight((short)1);
    style.setBorderTop((short)1);
    style.setFont(font);

    if(data.size()>0){
        Sheet sheet = wb.getSheetAt(0);
        int rownum = 1;
        for(XxDto item : data){
            Row row = sheet.createRow(rownum++);
            int cellnum = 0;
            row.createCell(cellnum++).setCellValue(item.getXxx());
            row.createCell(cellnum++).setCellValue(item.getXxx());
            row.createCell(cellnum++).setCellValue(item.getXxx());
            row.createCell(cellnum++).setCellValue(item.getXxx());
            row.createCell(cellnum++).setCellValue(item.getXxx());
            row.createCell(cellnum++).setCellValue(item.getXxx());
            row.createCell(cellnum++).setCellValue(item.getXxx());

            //设置样式
            for(int i=0; i<cellnum; i++){
                row.getCell(i).setCellStyle(style);
            }
        }
    }
    OutputStream os = new ByteArrayOutputStream();
    wb.write(os);
    return os;
}

当没有模板时需要创建文件（2007和2007以前的execl的写法是不同的）

Workbook wb;
  Sheet sheet;

File file = new File(fileName);
//文件不存在
if(!file.exists()){
    addFlag = false;
}
if(!addFlag){
    if("xls".equals(fileSuffix)){
                //老execl
        wb = new HSSFWorkbook();
    }else{
                //新execl
        wb = new XSSFWorkbook();
    }
    sheet = wb.createSheet("data");
    createExeclHead(sheet);
}else{
        //利用工厂读取execl可以不需要关心execl的版本问题
    wb = WorkbookFactory.create(file);
    sheet = wb.getSheetAt(0);
}

更详细的用法可以去官网看文档:http://poi.apache.org/