POI操作EXCEL对象

标签：对象 poi EXCEL new workbook HSSFCellStyle POI apache import

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;
    }
}

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);
    }

4.POI依赖的jar包（maven pom)

org.apache.poi poi-ooxml 3.14

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。

标签：对象,poi,EXCEL,new,workbook,HSSFCellStyle,POI,apache,import
From： https://www.cnblogs.com/xy1857/p/16667692.html

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