POI通用导出Excel(.xls,.xlsx)的方法

POI操作EXCEL对象
HSSF：操作Excel 97(.xls)格式
XSSF：操作Excel 2007 OOXML (.xlsx)格式，操作EXCEL内存占用高于HSSF
SXSSF:从POI3.8 beta3开始支持，基于XSSF，低内存占用。

使用POI的HSSF对象，生成Excel 97(.xls)格式，生成的EXCEL不经过压缩直接导出。
线上问题：负载服务器转发请求到应用服务器阻塞,以及内存溢出 。
如果系统存在大数据量报表导出，则考虑使用POI的SXSSF进行EXCEL操作。

HSSF生成的Excel 97(.xls)格式本身就有每个sheet页不能超过65536条的限制。
XSSF生成Excel 2007 OOXML (.xlsx)格式，条数增加了，但是导出过程中，内存占用率却高于HSSF.
SXSSF是自3.8-beta3版本后，基于XSSF提供的低内存占用的操作EXCEL对象。其原理是可以设置或者手动将内存中的EXCEL行写到硬盘中，这样内存中只保存了少量的EXCEL行进行操作。

EXCEL的压缩率特别高，能达到80%，12M的文件压缩后才2M左右。 如果未经过压缩、不仅会占用用户带宽，且会导致负载服务器（apache）和应用服务器之间，长时间占用连接(二进制流转发)，导致负载服务器请求阻塞，不能提供服务。

一定要注意文件流的关闭

防止前台（页面）连续触发导出EXCEL

1.通用核心导出工具类 ExcelUtil.java

package sy.util;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.reflect.Method;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

import org.apache.poi.hpsf.SummaryInformation;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFClientAnchor;
import org.apache.poi.hssf.usermodel.HSSFComment;
import org.apache.poi.hssf.usermodel.HSSFFont;
import org.apache.poi.hssf.usermodel.HSSFPatriarch;
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.ss.formula.functions.T;
import org.apache.poi.ss.usermodel.CellStyle;
import org.apache.poi.ss.usermodel.DateUtil;
import org.apache.poi.ss.usermodel.Font;
import org.apache.poi.ss.util.CellRangeAddress;
import org.apache.poi.xssf.streaming.SXSSFCell;
import org.apache.poi.xssf.streaming.SXSSFRow;
import org.apache.poi.xssf.streaming.SXSSFSheet;
import org.apache.poi.xssf.streaming.SXSSFWorkbook;

import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;

public class ExcelUtil{
  public static String NO_DEFINE = "no_define";//未定义的字段
  public static String DEFAULT_DATE_PATTERN="yyyy年MM月dd日";//默认日期格式
  public static int DEFAULT_COLOUMN_WIDTH = 17;
  /**
   * 导出Excel 97(.xls)格式 ，少量数据
   * @param title 标题行
   * @param headMap 属性-列名
   * @param jsonArray 数据集
   * @param datePattern 日期格式，null则用默认日期格式
   * @param colWidth 列宽 默认 至少17个字节
   * @param out 输出流
   */
  public static void exportExcel(String title,Map<String, String> headMap,JSONArray jsonArray,String datePattern,int colWidth, OutputStream out) {
    if(datePattern==null) datePattern = DEFAULT_DATE_PATTERN;
    // 声明一个工作薄
    HSSFWorkbook workbook = new HSSFWorkbook();
    workbook.createInformationProperties();
    workbook.getDocumentSummaryInformation().setCompany("*****公司");
    SummaryInformation si = workbook.getSummaryInformation();
    si.setAuthor("JACK"); //填加xls文件作者信息
    si.setApplicationName("导出程序"); //填加xls文件创建程序信息
    si.setLastAuthor("最后保存者信息"); //填加xls文件最后保存者信息
    si.setComments("JACK is a programmer!"); //填加xls文件作者信息
    si.setTitle("POI导出Excel"); //填加xls文件标题信息
    si.setSubject("POI导出Excel");//填加文件主题信息
    si.setCreateDateTime(new Date());
     //表头样式
    HSSFCellStyle titleStyle = workbook.createCellStyle();
    titleStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
    HSSFFont titleFont = workbook.createFont();
    titleFont.setFontHeightInPoints((short) 20);
    titleFont.setBoldweight((short) 700);
    titleStyle.setFont(titleFont);
    // 列头样式
    HSSFCellStyle headerStyle = workbook.createCellStyle();
    headerStyle.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
    headerStyle.setBorderBottom(HSSFCellStyle.BORDER_THIN);
    headerStyle.setBorderLeft(HSSFCellStyle.BORDER_THIN);
    headerStyle.setBorderRight(HSSFCellStyle.BORDER_THIN);
    headerStyle.setBorderTop(HSSFCellStyle.BORDER_THIN);
    headerStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
    HSSFFont headerFont = workbook.createFont();
    headerFont.setFontHeightInPoints((short) 12);
    headerFont.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
    headerStyle.setFont(headerFont);
    // 单元格样式
    HSSFCellStyle cellStyle = workbook.createCellStyle();
    cellStyle.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
    cellStyle.setBorderBottom(HSSFCellStyle.BORDER_THIN);
    cellStyle.setBorderLeft(HSSFCellStyle.BORDER_THIN);
    cellStyle.setBorderRight(HSSFCellStyle.BORDER_THIN);
    cellStyle.setBorderTop(HSSFCellStyle.BORDER_THIN);
    cellStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
    cellStyle.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);
    HSSFFont cellFont = workbook.createFont();
    cellFont.setBoldweight(HSSFFont.BOLDWEIGHT_NORMAL);
    cellStyle.setFont(cellFont);
    // 生成一个(带标题)表格
    HSSFSheet sheet = workbook.createSheet();
    // 声明一个画图的顶级管理器
    HSSFPatriarch patriarch = sheet.createDrawingPatriarch();
    // 定义注释的大小和位置,详见文档
    HSSFComment comment = patriarch.createComment(new HSSFClientAnchor(0,
        0, 0, 0, (short) 4, 2, (short) 6, 5));
    // 设置注释内容
    comment.setString(new HSSFRichTextString("可以在POI中添加注释！"));
    // 设置注释作者，当鼠标移动到单元格上是可以在状态栏中看到该内容.
    comment.setAuthor("JACK");
    //设置列宽
    int minBytes = colWidth<DEFAULT_COLOUMN_WIDTH?DEFAULT_COLOUMN_WIDTH:colWidth;//至少字节数
    int[] arrColWidth = new int[headMap.size()];
    // 产生表格标题行,以及设置列宽
    String[] properties = new String[headMap.size()];
    String[] headers = new String[headMap.size()];
    int ii = 0;
    for (Iterator<String> iter = headMap.keySet().iterator(); iter
        .hasNext();) {
      String fieldName = iter.next();

      properties[ii] = fieldName;
      headers[ii] = fieldName;

      int bytes = fieldName.getBytes().length;
      arrColWidth[ii] = bytes < minBytes ? minBytes : bytes;
      sheet.setColumnWidth(ii,arrColWidth[ii]*256);
      ii++;
    }
    // 遍历集合数据，产生数据行
    int rowIndex = 0;
    for (Object obj : jsonArray) {
      if(rowIndex == 65535 || rowIndex == 0){
        if ( rowIndex != 0 ) sheet = workbook.createSheet();//如果数据超过了，则在第二页显示

        HSSFRow titleRow = sheet.createRow(0);//表头 rowIndex=0
        titleRow.createCell(0).setCellValue(title);
        titleRow.getCell(0).setCellStyle(titleStyle);
        sheet.addMergedRegion(new CellRangeAddress(0, 0, 0, headMap.size() - 1));

        HSSFRow headerRow = sheet.createRow(1); //列头 rowIndex =1
        for(int i=0;i<headers.length;i++)
        {
          headerRow.createCell(i).setCellValue(headers[i]);
          headerRow.getCell(i).setCellStyle(headerStyle);

        }
        rowIndex = 2;//数据内容从 rowIndex=2开始
      }
      JSONObject jo = (JSONObject) JSONObject.toJSON(obj);
      HSSFRow dataRow = sheet.createRow(rowIndex);
      for (int i = 0; i < properties.length; i++)
      {
        HSSFCell newCell = dataRow.createCell(i);

        Object o = jo.get(properties[i]);
        String cellValue = "";
        if(o==null) cellValue = "";
        else if(o instanceof Date) cellValue = new SimpleDateFormat(datePattern).format(o);
        else cellValue = o.toString();

        newCell.setCellValue(cellValue);
        newCell.setCellStyle(cellStyle);
      }
      rowIndex++;
    }
    // 自动调整宽度
    /*for (int i = 0; i < headers.length; i++) {
      sheet.autoSizeColumn(i);
    }*/
    try {
      workbook.write(out);
      workbook.close();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
  /**
   * 导出Excel 2007 OOXML (.xlsx)格式
   * @param title 标题行
   * @param headMap 属性-列头
   * @param jsonArray 数据集
   * @param datePattern 日期格式，传null值则默认 年月日
   * @param colWidth 列宽 默认 至少17个字节
   * @param out 输出流
   */
  public static void exportExcelX(String title,Map<String, String> headMap,JSONArray jsonArray,String datePattern,int colWidth, OutputStream out) {
    if(datePattern==null) datePattern = DEFAULT_DATE_PATTERN;
    // 声明一个工作薄
    SXSSFWorkbook workbook = new SXSSFWorkbook(1000);//缓存
    workbook.setCompressTempFiles(true);
     //表头样式
    CellStyle titleStyle = workbook.createCellStyle();
    titleStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
    Font titleFont = workbook.createFont();
    titleFont.setFontHeightInPoints((short) 20);
    titleFont.setBoldweight((short) 700);
    titleStyle.setFont(titleFont);
    // 列头样式
    CellStyle headerStyle = workbook.createCellStyle();
    headerStyle.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
    headerStyle.setBorderBottom(HSSFCellStyle.BORDER_THIN);
    headerStyle.setBorderLeft(HSSFCellStyle.BORDER_THIN);
    headerStyle.setBorderRight(HSSFCellStyle.BORDER_THIN);
    headerStyle.setBorderTop(HSSFCellStyle.BORDER_THIN);
    headerStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
    Font headerFont = workbook.createFont();
    headerFont.setFontHeightInPoints((short) 12);
    headerFont.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
    headerStyle.setFont(headerFont);
    // 单元格样式
    CellStyle cellStyle = workbook.createCellStyle();
    cellStyle.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
    cellStyle.setBorderBottom(HSSFCellStyle.BORDER_THIN);
    cellStyle.setBorderLeft(HSSFCellStyle.BORDER_THIN);
    cellStyle.setBorderRight(HSSFCellStyle.BORDER_THIN);
    cellStyle.setBorderTop(HSSFCellStyle.BORDER_THIN);
    cellStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
    cellStyle.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);
    Font cellFont = workbook.createFont();
    cellFont.setBoldweight(HSSFFont.BOLDWEIGHT_NORMAL);
    cellStyle.setFont(cellFont);
    // 生成一个(带标题)表格
    SXSSFSheet sheet = workbook.createSheet();
    //设置列宽
    int minBytes = colWidth<DEFAULT_COLOUMN_WIDTH?DEFAULT_COLOUMN_WIDTH:colWidth;//至少字节数
    int[] arrColWidth = new int[headMap.size()];
    // 产生表格标题行,以及设置列宽
    String[] properties = new String[headMap.size()];
    String[] headers = new String[headMap.size()];
    int ii = 0;
    for (Iterator<String> iter = headMap.keySet().iterator(); iter
        .hasNext();) {
      String fieldName = iter.next();

      properties[ii] = fieldName;
      headers[ii] = headMap.get(fieldName);

      int bytes = fieldName.getBytes().length;
      arrColWidth[ii] = bytes < minBytes ? minBytes : bytes;
      sheet.setColumnWidth(ii,arrColWidth[ii]*256);
      ii++;
    }
    // 遍历集合数据，产生数据行
    int rowIndex = 0;
    for (Object obj : jsonArray) {
      if(rowIndex == 65535 || rowIndex == 0){
        if ( rowIndex != 0 ) sheet = workbook.createSheet();//如果数据超过了，则在第二页显示

        SXSSFRow titleRow = sheet.createRow(0);//表头 rowIndex=0
        titleRow.createCell(0).setCellValue(title);
        titleRow.getCell(0).setCellStyle(titleStyle);
        sheet.addMergedRegion(new CellRangeAddress(0, 0, 0, headMap.size() - 1));

        SXSSFRow headerRow = sheet.createRow(1); //列头 rowIndex =1
        for(int i=0;i<headers.length;i++)
        {
          headerRow.createCell(i).setCellValue(headers[i]);
          headerRow.getCell(i).setCellStyle(headerStyle);

        }
        rowIndex = 2;//数据内容从 rowIndex=2开始
      }
      JSONObject jo = (JSONObject) JSONObject.toJSON(obj);
      SXSSFRow dataRow = sheet.createRow(rowIndex);
      for (int i = 0; i < properties.length; i++)
      {
        SXSSFCell newCell = dataRow.createCell(i);

        Object o = jo.get(properties[i]);
        String cellValue = "";
        if(o==null) cellValue = "";
        else if(o instanceof Date) cellValue = new SimpleDateFormat(datePattern).format(o);
        else if(o instanceof Float || o instanceof Double)
          cellValue= new BigDecimal(o.toString()).setScale(2,BigDecimal.ROUND_HALF_UP).toString();
        else cellValue = o.toString();

        newCell.setCellValue(cellValue);
        newCell.setCellStyle(cellStyle);
      }
      rowIndex++;
    }
    // 自动调整宽度
    /*for (int i = 0; i < headers.length; i++) {
      sheet.autoSizeColumn(i);
    }*/
    try {
      workbook.write(out);
      workbook.close();
      workbook.dispose();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
  //Web 导出excel
  public static void downloadExcelFile(String title,Map<String,String> headMap,JSONArray ja,HttpServletResponse response){
    try {
      ByteArrayOutputStream os = new ByteArrayOutputStream();
      ExcelUtil.exportExcelX(title,headMap,ja,null,0,os);
      byte[] content = os.toByteArray();
      InputStream is = new ByteArrayInputStream(content);
      // 设置response参数，可以打开下载页面
      response.reset();

      response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet;charset=utf-8");
      response.setHeader("Content-Disposition", "attachment;filename="+ new String((title + ".xlsx").getBytes(), "iso-8859-1"));
      response.setContentLength(content.length);
      ServletOutputStream outputStream = response.getOutputStream();
      BufferedInputStream bis = new BufferedInputStream(is);
      BufferedOutputStream bos = new BufferedOutputStream(outputStream);
      byte[] buff = new byte[8192];
      int bytesRead;
      while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) {
        bos.write(buff, 0, bytesRead);

      }
      bis.close();
      bos.close();
      outputStream.flush();
      outputStream.close();
    }catch (Exception e) {
      e.printStackTrace();
    }
  }
  public static void main(String[] args) throws IOException {
    int count = 100000;
    JSONArray ja = new JSONArray();
    for(int i=0;i<100000;i++){
      Student s = new Student();
      s.setName("POI"+i);
      s.setAge(i);
      s.setBirthday(new Date());
      s.setHeight(i);
      s.setWeight(i);
      s.setSex(i/2==0?false:true);
      ja.add(s);
    }
    Map<String,String> headMap = new LinkedHashMap<String,String>();
    headMap.put("name","姓名");
    headMap.put("age","年龄");
    headMap.put("birthday","生日");
    headMap.put("height","身高");
    headMap.put("weight","体重");
    headMap.put("sex","性别");

    String title = "测试";
    /*
    OutputStream outXls = new FileOutputStream("E://a.xls");
    System.out.println("正在导出xls....");
    Date d = new Date();
    ExcelUtil.exportExcel(title,headMap,ja,null,outXls);
    System.out.println("共"+count+"条数据,执行"+(new Date().getTime()-d.getTime())+"ms");
    outXls.close();*/
    //
    OutputStream outXlsx = new FileOutputStream("E://b.xlsx");
    System.out.println("正在导出xlsx....");
    Date d2 = new Date();
    ExcelUtil.exportExcelX(title,headMap,ja,null,0,outXlsx);
    System.out.println("共"+count+"条数据,执行"+(new Date().getTime()-d2.getTime())+"ms");
    outXlsx.close();

  }
}
class Student {
  private String name;
  private int age;
  private Date birthday;
  private float height;
  private double weight;
  private boolean sex;

  public String getName() {
    return name;
  }

  public void setName(String name) {
    this.name = name;
  }

  public Integer getAge() {
    return age;
  }

  public Date getBirthday() {
    return birthday;
  }

  public void setBirthday(Date birthday) {
    this.birthday = birthday;
  }

  public float getHeight() {
    return height;
  }

  public void setHeight(float height) {
    this.height = height;
  }

  public double getWeight() {
    return weight;
  }

  public void setWeight(double weight) {
    this.weight = weight;
  }

  public boolean isSex() {
    return sex;
  }

  public void setSex(boolean sex) {
    this.sex = sex;
  }

  public void setAge(Integer age) {
    this.age = age;
  }
}

2. 控制器Controller 的写法

//导出配件列表
  @RequestMapping(value = "partExport")
  @ResponseBody
  public void partExportHttpServletResponse response){

    JSONArray ja = ptmpOrderService.selectStatExport();//获取业务数据集
    Map<String,String> headMap = ptmpOrderService.getPartStatHeadMap();//获取属性-列头
    String title = "配件统计表";
    ExcelUtil.downloadExcelFile(title,headMap,ja,response);
  }

3.前端页面的写法（不要用异步方式请求，如$.post）

//可以点击一个按钮事件触发下面的代码进行导出
window.open("partExport","_blank");
//或者可以提交表单
$('#form').attr('action','partExport');
$('#form').attr('target','_blank');
$('#form').submit();

4.POI依赖的jar包（maven pom)

<dependency>
  <groupId>org.apache.poi</groupId>
  <artifactId>poi-ooxml</artifactId>
  <version>3.14</version>
</dependency>

5.本地测试

将10w条数据导出到本地硬盘中，HSSF方式用时14s左右，SXSSF方式用时24s左右，尽管如此，但建议使用SXSSF导出.xlsx的excel.

之所以使用JSONArray作为数据集，而没有采用java的集合类，是因为JSONObject 在获取数据的时候是采用 get(key)的方式，正好与属性列对应，这样灵活性高，属性列不必与java对象的字段匹配。而若使用java类，则要应用反射，拼凑get方法，这样更复杂点。

以上所述是小编给大家介绍的POI通用导出Excel(.xls,.xlsx)的方法详解整合，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对我们网站的支持！