JavaWeb项目操作Excel（导出、解析）

对于javaweb开发者来说，对于Excel的操作是必须要了解的知识点，自己原先也做过一些excel的操作，但是没有系统的整理过，所以每回使用的时候都是在重新查找信息，所以做了如下整理：

其实在javaweb开发中经常用到的Excel操作便是导出、解析。下面就从这两个方面来总结。

首先便是导出，在这个方面其实我主要用到的是两种方式：一种是依赖于freemarker，另一种则是POI

一、依赖于freemarker的Excel导出：

首先如果要使用freemarker的导出方式，在框架中必须使用了freemarker这个模板引擎，对于现在主流的mvc框架来说：spring mvc是可以集成freemarker的，spring boot则更近一步，spring mvc推荐使用jsp，而spring boot 推荐使用freemarker。至于Struts2本人没有涉及过不是很清楚，需要自己去探索啊！！不过应该也是没有问题的。然后就是Struts这个东西，我想现在应该没有公司在用Struts了吧！！！

好！！闲话不多直接上操作步骤，我这里的代码是使用的spring boot+freemarker的方式，至于dao层本文档不会涉及其内容：

（一）、首先要做的便是将要导出的Excel的模板准备好，接编写一个Excel表格，如图：

 

（二）、将Excel另存为xml格式：

然后用文本编辑器打开Excel文件看到内容为：

<?xml version="1.0"?>
<?mso-application progid="Excel.Sheet"?>
<Workbook xmlns="urn:schemas-microsoft-com:office:spreadsheet"
 xmlns:o="urn:schemas-microsoft-com:office:office"
 xmlns:x="urn:schemas-microsoft-com:office:excel"
 xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet"
 xmlns:html="http://www.w3.org/TR/REC-html40">
 <DocumentProperties xmlns="urn:schemas-microsoft-com:office:office">
  <Created>2006-09-16T00:00:00Z</Created>
  <LastSaved>2018-10-22T03:45:04Z</LastSaved>
  <Version>15.00</Version>
 </DocumentProperties>
 <OfficeDocumentSettings xmlns="urn:schemas-microsoft-com:office:office">
  <AllowPNG/>
  <RemovePersonalInformation/>
 </OfficeDocumentSettings>
 <ExcelWorkbook xmlns="urn:schemas-microsoft-com:office:excel">
  <WindowHeight>8010</WindowHeight>
  <WindowWidth>14805</WindowWidth>
  <WindowTopX>240</WindowTopX>
  <WindowTopY>105</WindowTopY>
  <ProtectStructure>False</ProtectStructure>
  <ProtectWindows>False</ProtectWindows>
 </ExcelWorkbook>
 <Styles>
  <Style ss:ID="Default" ss:Name="Normal">
   <Alignment ss:Vertical="Bottom"/>
   <Borders/>
   <Font ss:FontName="宋体" ss:Size="11" ss:Color="#000000"/>
   <Interior/>
   <NumberFormat/>
   <Protection/>
  </Style>
  <Style ss:ID="s16">
   <Alignment ss:Horizontal="Center" ss:Vertical="Center"/>
  </Style>
  <Style ss:ID="s17">
   <Alignment ss:Horizontal="Center" ss:Vertical="Bottom"/>
  </Style>
  <Style ss:ID="s18">
   <Alignment ss:Vertical="Center" ss:WrapText="1"/>
  </Style>
  <Style ss:ID="s19">
   <Alignment ss:Horizontal="Center" ss:Vertical="Center"/>
   <NumberFormat ss:Format="yyyy/m/d hh:mm:ss"/>
  </Style>
 </Styles>
 <Worksheet ss:Name="存储池">
  <Table ss:ExpandedColumnCount="4" ss:ExpandedRowCount="2" x:FullColumns="1"
   x:FullRows="1" ss:DefaultColumnWidth="54" ss:DefaultRowHeight="13.5">
   <Column ss:AutoFitWidth="0" ss:Width="123.75" ss:Span="3"/>
   <Row>
    <Cell ss:StyleID="s16"><Data ss:Type="String">存储池名</Data></Cell>
    <Cell ss:StyleID="s16"><Data ss:Type="String">总容量（TB）</Data></Cell>
    <Cell ss:StyleID="s16"><Data ss:Type="String">已使用容量（TB）</Data></Cell>
    <Cell ss:StyleID="s16"><Data ss:Type="String">未使用容量（TB）</Data></Cell>
   </Row>
   <Row>
    <Cell ss:StyleID="s16"><Data ss:Type="String">pool0</Data></Cell>
    <Cell ss:StyleID="s16"><Data ss:Type="Number">5.68</Data></Cell>
    <Cell ss:StyleID="s16"><Data ss:Type="Number">1.23</Data></Cell>
    <Cell ss:StyleID="s17"><Data ss:Type="Number">2.33</Data></Cell>
   </Row>
  </Table>
  <WorksheetOptions xmlns="urn:schemas-microsoft-com:office:excel">
   <PageSetup>
    <Header x:Margin="0.3"/>
    <Footer x:Margin="0.3"/>
    <PageMargins x:Bottom="0.75" x:Left="0.7" x:Right="0.7" x:Top="0.75"/>
   </PageSetup>
   <Print>
    <ValidPrinterInfo/>
    <PaperSizeIndex>9</PaperSizeIndex>
    <HorizontalResolution>600</HorizontalResolution>
    <VerticalResolution>600</VerticalResolution>
   </Print>
   <Selected/>
   <Panes>
    <Pane>
     <Number>3</Number>
     <ActiveCol>4</ActiveCol>
    </Pane>
   </Panes>
   <ProtectObjects>False</ProtectObjects>
   <ProtectScenarios>False</ProtectScenarios>
  </WorksheetOptions>
 </Worksheet>
 <Worksheet ss:Name="报错日志">
  <Table ss:ExpandedColumnCount="3" ss:ExpandedRowCount="2" x:FullColumns="1"
   x:FullRows="1" ss:DefaultColumnWidth="54" ss:DefaultRowHeight="13.5">
   <Column ss:AutoFitWidth="0" ss:Width="153"/>
   <Column ss:AutoFitWidth="0" ss:Width="81.75"/>
   <Column ss:AutoFitWidth="0" ss:Width="605.25"/>
   <Row ss:AutoFitHeight="0" ss:Height="20.0625">
    <Cell ss:StyleID="s16"><Data ss:Type="String">时间</Data></Cell>
    <Cell ss:StyleID="s16"><Data ss:Type="String">级别</Data></Cell>
    <Cell ss:StyleID="s16"><Data ss:Type="String">内容</Data></Cell>
   </Row>
   <Row ss:Height="27">
    <Cell ss:StyleID="s19"><Data ss:Type="String" x:Ticked="1">2017/12/12  11:11:11</Data></Cell>
    <Cell ss:StyleID="s16"><Data ss:Type="String">error</Data></Cell>
    <Cell ss:StyleID="s18"><Data ss:Type="String">fdsafdsafdsafdsafdsafdsafdsafdsafdsafdsafdsafdsafdsafdsafdsafdsafdsafdsafdsasdfdsafsddddddddddddddddddddddddddfsaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa</Data></Cell>
   </Row>
  </Table>
  <WorksheetOptions xmlns="urn:schemas-microsoft-com:office:excel">
   <PageSetup>
    <Header x:Margin="0.3"/>
    <Footer x:Margin="0.3"/>
    <PageMargins x:Bottom="0.75" x:Left="0.7" x:Right="0.7" x:Top="0.75"/>
   </PageSetup>
   <Print>
    <ValidPrinterInfo/>
    <PaperSizeIndex>9</PaperSizeIndex>
    <HorizontalResolution>600</HorizontalResolution>
    <VerticalResolution>600</VerticalResolution>
   </Print>
   <Panes>
    <Pane>
     <Number>3</Number>
     <ActiveRow>1</ActiveRow>
    </Pane>
   </Panes>
   <ProtectObjects>False</ProtectObjects>
   <ProtectScenarios>False</ProtectScenarios>
  </WorksheetOptions>
 </Worksheet>
</Workbook>

（三）、接下来便是将xml代码复制到一个新建的freemarker模板文件中便可以了

（四）、下面便是java代码的编写了，废话不多直接上代码：

@RequestMapping("/exportreport")
    private String exportReport(Model model,HttpServletRequest request,HttpServletResponse response,int did) {
        
        //获取要导入的信息
        List<DPool> poolList=reportService.selectPoolByDid(did);
        List<DAlarm> alarmList=reportService.selectAlarmByDid(did);
        Device device = deviceDao.selectByPrimaryKey(did);
        
        
        //将需要到导入的信息存入model中
        model.addAttribute("poolList", poolList);
        model.addAttribute("alarmList", alarmList);
        
        
        //设置下载头部，通过response实现
        response.reset();
        response.setContentType("application/vnd.ms-excel;charset=utf-8");
        try {
            response.addHeader("Content-Disposition", "attachment; filename=" + URLEncoder.encode(device.getName()+"-report.xls", "UTF8"));
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        //带导出数据跳转到freemarker模板
        return "generate_reports";
    }

 （五）、最后便是利用freemarker的知识去编写，上面新建的模板了，将数据插入到模板中，其中有些地方需要注意一下：

　　这个地方的数字代表了这张工作表中有多少行

二、第二种方式便是利用POI了，步骤如下：

　　（一）、利用poi生成Excel表格

package cn.tools;

import java.text.DecimalFormat;
import java.util.List;

import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFFont;
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.ss.usermodel.HorizontalAlignment;
import org.apache.poi.ss.usermodel.VerticalAlignment;

import cn.entitys.DAlarm;
import cn.entitys.DPool;

public class GenerateReport {
    public static HSSFWorkbook Generate(List<DPool> poolList, List<DAlarm> alarmList){
        HSSFWorkbook workbook = new HSSFWorkbook();
        HSSFSheet firstsheet = workbook.createSheet("存储池");
        
        HSSFFont font = workbook.createFont();
        font.setFontName("宋体");
        font.setFontHeightInPoints((short) 11);
        
        HSSFCellStyle cellStyle1 = workbook.createCellStyle();
        cellStyle1.setAlignment(HorizontalAlignment.CENTER);
        cellStyle1.setVerticalAlignment(VerticalAlignment.CENTER);
        cellStyle1.setFont(font);

        firstsheet.setColumnWidth(0, 20*265);
        firstsheet.setColumnWidth(1, 20*265);
        firstsheet.setColumnWidth(2, 20*265);
        firstsheet.setColumnWidth(3, 20*265);
        firstsheet.setDefaultColumnStyle(0, cellStyle1);
        firstsheet.setDefaultColumnStyle(1, cellStyle1);
        firstsheet.setDefaultColumnStyle(2, cellStyle1);
        firstsheet.setDefaultColumnStyle(3, cellStyle1);

        HSSFRow row = firstsheet.createRow(0);
        row.setHeight((short) (13.5*20));
        row.createCell(0).setCellValue("存储池名");
        row.createCell(1).setCellValue("总容量（TB）");
        row.createCell(2).setCellValue("已使用容量（TB）");
        row.createCell(3).setCellValue("未使用容量（TB）");
        
        double d = Math.random()*10;
        DecimalFormat dFormat = new DecimalFormat("#.00");
        for (int i=0;i<poolList.size();i++) {
            DPool pool=poolList.get(i);
            row = firstsheet.createRow(i+1);
            row.setHeight((short) (13.5*20));
            row.createCell(0).setCellValue(pool.getName());
            row.createCell(1).setCellValue(pool.getCapacity());
            row.createCell(2).setCellValue(pool.getUsed_capacity());
            row.createCell(3).setCellValue(pool.getFree_capacity());
        }
        
        HSSFSheet secondsheet = workbook.createSheet("报错日志");
        
        HSSFCellStyle cellStyle2 = workbook.createCellStyle();
        cellStyle2.setVerticalAlignment(VerticalAlignment.CENTER);
        cellStyle2.setAlignment(HorizontalAlignment.LEFT);
        cellStyle2.setFont(font);
        cellStyle2.setWrapText(true);
        
        HSSFCellStyle cellStyle3 = workbook.createCellStyle();
        cellStyle3.setAlignment(HorizontalAlignment.CENTER);
        cellStyle3.setFont(font);
        
        secondsheet.setColumnWidth(0, 25*265);
        secondsheet.setColumnWidth(1, 13*265);
        secondsheet.setColumnWidth(2, 100*265);
        secondsheet.setDefaultColumnStyle(0, cellStyle1);
        secondsheet.setDefaultColumnStyle(1, cellStyle1);
        secondsheet.setDefaultColumnStyle(2, cellStyle2);
        
        HSSFRow row2 = secondsheet.createRow(0);
        row2.setHeight((short) (20*20));
        row2.createCell(0).setCellValue("时间");
        row2.createCell(1).setCellValue("级别");
        row2.createCell(2).setCellValue("内容");
        row2.getCell(2).setCellStyle(cellStyle3);
        for(int i=0;i<alarmList.size();i++){
            DAlarm alarm=alarmList.get(i);
            row2 = secondsheet.createRow(i+1);
            row2.setHeight((short) (27*20));
            row2.createCell(0).setCellValue(alarm.getTime());
            row2.createCell(1).setCellValue(alarm.getLevel());
            row2.createCell(2).setCellValue(alarm.getContext());
        }
        return workbook;
    }
}

　　　　　　

　　（二）、设置control中的下载头部，这里和freemarker的导出是一样的。

　　（三）、利用输入输出流，输出到浏览器

package cn.Controllers;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.text.DecimalFormat;
import java.util.List;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFFont;
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.ss.usermodel.HorizontalAlignment;
import org.apache.poi.ss.usermodel.VerticalAlignment;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import cn.dao.DeviceMapper;
import cn.entitys.DAlarm;
import cn.entitys.DPool;
import cn.entitys.Device;
import cn.service.ReportService;
import cn.service.ThreadService;
import cn.tools.GenerateReport;

@Controller
@RequestMapping("/report")
public class ReportController {
    
    @Autowired
    ReportService reportService;
    
    @Autowired
    ThreadService threadService;
    
    @Autowired
    DeviceMapper deviceDao;
    
    @RequestMapping("/exportreport")
    private void exportReport(Model model,HttpServletRequest request,HttpServletResponse response,int did) throws IOException {
        
        //获取要导入的信息
        List<DPool> poolList=reportService.selectPoolByDid(did);
        List<DAlarm> alarmList=reportService.selectAlarmByDid(did);
        Device device = deviceDao.selectByPrimaryKey(did);
        
        
        //生成Excel表
        HSSFWorkbook workbook = GenerateReport.Generate(poolList, alarmList);
        
        
        //设置下载头部，通过response实现
        response.reset();
        response.setContentType("application/vnd.ms-excel;charset=utf-8");
        try {
            response.addHeader("Content-Disposition", "attachment; filename=" + URLEncoder.encode(device.getName()+"-report.xls", "UTF8"));
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        ServletOutputStream fileOut = response.getOutputStream();
        workbook.write(fileOut); 
    }
    98 }

这里没有编写代码，后续会跟上的。

三、Excel的解析：

其实这一部分可以分为两部分来讲解 ，首先涉及到的便是文件的上传，毕竟有文件上传了才能进行解析，然后便是利用POI解析上传后的文件获取数据，

至于POI 的操作会在下一篇博客中整理。