Excel导出百万级数据解决方案

因项目业务，需要导出百万级数据到excel，在研究了各种方案后，最终确定了用POI的SXSSFWorkbook。

SXSSFWorkbook是POI3.8以上新增的，excel2007后每个sheet支持104万行数据，基于此条件，将得到数据进行分页创建；

并且代码还要通用，无论你传递过来什么对象，多少列都要正常显示。

具体将excel分成4大区域：

1. 标题（title）
2. 查询条件（condition）：具体封装为map
3. 列头 （headList）：以bean队列形式传递，name为显示的中文名称，column为实际属性
4. 数据（dataList）：以map队列形式传递，key为实际属性（和head中的column要对应），value为实际值（特殊值建议提前格式化）

具体代码如下，只要注意headList中的column和dataList中的column对应，相信能适合大多数场景：

• 工具类
  
  ```

package com.cmos.utils;

import java.io.File;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.OutputStream;

import java.util.Iterator;

import java.util.List;

import java.util.Map;

import java.util.TreeMap;

import org.apache.poi.hssf.util.HSSFColor;

import org.apache.poi.ss.usermodel.BorderStyle;

import org.apache.poi.ss.usermodel.Cell;

import org.apache.poi.ss.usermodel.CellStyle;

import org.apache.poi.ss.usermodel.FillPatternType;

import org.apache.poi.ss.usermodel.Font;

import org.apache.poi.ss.usermodel.HorizontalAlignment;

import org.apache.poi.ss.usermodel.Row;

import org.apache.poi.ss.usermodel.Sheet;

import org.apache.poi.ss.usermodel.VerticalAlignment;

import org.apache.poi.ss.util.CellRangeAddress;

import org.apache.poi.xssf.streaming.SXSSFWorkbook;

import org.apache.poi.xssf.usermodel.XSSFRichTextString;

import com.cmos.utils.ExcelData.Head;

/**

• 导出excel，支持海量数据，可分sheet
• 实测：50万数据 40s左右
• 100万数据 80秒左右
• （具体和运行环境有关）
• @author zsx

• */
  
  public class ExcelUtil {
  
  final int memorySize = 100;//内存中只创建100个对象，写临时文件，当超过100条，就将内存中不用的对象释放
  
  final int sheetRowMax = 200000;// 单sheet最大行数，用于分页

  /**

  • 动态创建excel，将所有数据以ExcelData方式传递进来：
  • title：标题，用于显示在最上方
  • condition：查询条件，以map形式传递
  • headList：列头，以bean队列形式传递，name为显示的中文名称，column为实际属性
  • dataList：数据，以map队列形式传递，key为实际属性（和head中的column要对应），value为实际值（特殊值建议提前格式化）
    
    */
    
    public void export(ExcelData data,File file) throws IOException{
    
    long st = System.currentTimeMillis();
    
    ExcelUtil.judeFileExists(file);
    
    ExcelUtil eu = new ExcelUtil();
    
    OutputStream out = new FileOutputStream(file.getPath());
    
    eu.exportExcel(data, out);
    
    out.close();
    
    long et = System.currentTimeMillis();
    
    System.out.println("export excel:"+(et-st)+"ms");
    
    }

  /**

  • 导出核心
  • @param data

  • @param out
    
    */
    
    private void exportExcel(ExcelData data, OutputStream out) {
    
    // 校验
    
    if (data == null || data.getHeadList() == null || data.getDataList() == null) {
    
    System.out.println("准备数据不能为空");
    
    return;
    
    }
    
    // 数据准备
    
    String title = data.getTitle();
    
    Map

    //为防止数据量过大导致OOM，POI3.8以上支持大数据导出
    
    SXSSFWorkbook workbook = new SXSSFWorkbook(memorySize);
    
    Sheet sheet = null;

    int sheetSize = 1;
    
    if (dataList.size() > sheetRowMax) {
    
    if (dataList.size() % sheetRowMax == 0) {
    
    sheetSize = dataList.size() / sheetRowMax;
    
    } else {
    
    sheetSize = dataList.size() / sheetRowMax + 1;
    
    }
    
    }
    
    // 设置样式
    
    CellStyle titleStyle = getTitleStyle(workbook);
    
    CellStyle HeadStyle = getHeadStyle(workbook);
    
    CellStyle dataStyle = getDataStyle(workbook);

    // 设置数据
    
    for (int i = 0; i < sheetSize; i++) {
    
    int startInx = sheetRowMaxi;
    
    int endInx = sheetRowMax(i+1)-1;
    
    //获取当页数据
    
    if(sheetRowMax*(i+1)-1 > dataList.size()){
    
    endInx = dataList.size();
    
    }
    
    List

    }
    
    try {
    
    workbook.write(out);
    
    } catch (IOException e) {
    
    e.printStackTrace();
    
    }

  }

  /**

  • 合并单元格
  • @param sheet
  • @param headSize

  • @param conditionSize
    
    */
    
    private void mergeCell(Sheet sheet, int headSize, int conditionSize) {
    
    //TODO 合并后样式被改变，需要进行优化 by zsx 20170717
    
    CellRangeAddress titleCra = new CellRangeAddress(0, 0, 0, headSize - 1);
    
    sheet.addMergedRegion(titleCra);

    for (int i = 0; i < conditionSize; i++) {
    
    CellRangeAddress conditionKeyCra = new CellRangeAddress(i + 1, i + 1, 0, 1);
    
    sheet.addMergedRegion(conditionKeyCra);
    
    CellRangeAddress conditionValueCra = new CellRangeAddress(i + 1, i + 1, 2, 3);
    
    sheet.addMergedRegion(conditionValueCra);
    
    }

  }

  /**

  • 创建数据
  • @param sheet
  • @param cellStyle
  • @param i
  • @param dataList
    
    */
    
    private void createDataRow(Sheet sheet, CellStyle cellStyle, int index,List headList, List

  /**

  • 创建列头
  • @param sheet
  • @param cellStyle
  • @param j
  • @param headList
    
    */
    
    private void createHeadRow(Sheet sheet, CellStyle cellStyle, int index, List headList) {
    
    Row row = sheet.createRow(index);
    
    row.setHeight((short) 300);
    
    for(int i=0;i<headList.size();i++){
    
    Cell cell = row.createCell(i);
    
    cell.setCellStyle(cellStyle);
    
    XSSFRichTextString text = new XSSFRichTextString(headList.get(i).getName());
    
    cell.setCellValue(text);
    
    }
    
    }

  /**

  • 创建查询
  • @param sheet
  • @param cellStyle
  • @param condition
    
    */
    
    private void createConditionRow(Sheet sheet, CellStyle cellStyle, Map

  }

  /**

  • 设置列宽
  • @param sheet
  • @param headList
    
    */
    
    private void setSheetWidth(Sheet sheet, List headList) {
    
    for (int i = 0; i < headList.size(); i++) {
    
    sheet.setColumnWidth(i, 4000);
    
    }
    
    }

  /**

  • 创建标题
  • @param sheet
  • @param cellStyle
  • @param title
    
    */
    
    private void createTitleRow(Sheet sheet, CellStyle cellStyle, String title) {
    
    Row row = sheet.createRow(0);
    
    row.setHeight((short) 500);
    
    Cell cell = row.createCell(0);
    
    cell.setCellStyle(cellStyle);
    
    XSSFRichTextString text = new XSSFRichTextString(title);
    
    cell.setCellValue(text);
    
    }

  /**

  • 设置标题样式
  • @param workbook

  • @return
    
    */
    
    private CellStyle getTitleStyle(SXSSFWorkbook workbook) {
    
    // 生成一个样式(标题行)
    
    CellStyle headStyle = workbook.createCellStyle();

    // 设置这些样式
    
    headStyle.setFillForegroundColor(HSSFColor.WHITE.index);
    
    headStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);
    
    headStyle.setBorderBottom(BorderStyle.THIN);
    
    headStyle.setBorderLeft(BorderStyle.THIN);
    
    headStyle.setBorderRight(BorderStyle.THIN);
    
    headStyle.setBorderTop(BorderStyle.THIN);
    
    headStyle.setAlignment(HorizontalAlignment.CENTER);
    
    headStyle.setVerticalAlignment(VerticalAlignment.CENTER);
    
    // 生成一个字体
    
    Font headFont = workbook.createFont();
    
    headFont.setFontHeightInPoints((short) 16);
    
    headFont.setFontName("Microsoft YaHei UI Light");
    
    headFont.setBold(true);
    
    headFont.setBold(true);
    
    // 把字体应用到当前的样式
    
    headStyle.setFont(headFont);

    return headStyle;
    
    }

  /**

  • 设置列头样式
  • @param workbook

  • @return
    
    */
    
    private CellStyle getHeadStyle(SXSSFWorkbook workbook) {
    
    // 生成一个样式(标题行)
    
    CellStyle headStyle = workbook.createCellStyle();

    // 设置这些样式
    
    headStyle.setFillForegroundColor(HSSFColor.GREY_25_PERCENT.index);
    
    headStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);
    
    headStyle.setBorderBottom(BorderStyle.THIN);
    
    headStyle.setBorderLeft(BorderStyle.THIN);
    
    headStyle.setBorderRight(BorderStyle.THIN);
    
    headStyle.setBorderTop(BorderStyle.THIN);
    
    headStyle.setAlignment(HorizontalAlignment.CENTER);
    
    headStyle.setAlignment(HorizontalAlignment.CENTER);
    
    // 生成一个字
    
    Font headFont = workbook.createFont();
    
    headFont.setFontHeightInPoints((short) 12);
    
    headFont.setFontName("Microsoft YaHei UI Light");
    
    headFont.setBold(true);
    
    // 把字体应用到当前的样式
    
    headStyle.setFont(headFont);

    return headStyle;
    
    }

  /**

  • 设置数据样式
  • @param workbook

  • @return
    
    */
    
    private CellStyle getDataStyle(SXSSFWorkbook workbook) {
    
    // 生成一个样式(标题行)
    
    CellStyle headStyle = workbook.createCellStyle();

    // 设置这些样式
    
    headStyle.setFillForegroundColor(HSSFColor.WHITE.index);
    
    headStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);
    
    headStyle.setBorderBottom(BorderStyle.THIN);
    
    headStyle.setBorderLeft(BorderStyle.THIN);
    
    headStyle.setBorderRight(BorderStyle.THIN);
    
    headStyle.setBorderTop(BorderStyle.THIN);
    
    headStyle.setAlignment(HorizontalAlignment.CENTER);
    
    // 生成一个字体
    
    Font headFont = workbook.createFont();
    
    headFont.setFontHeightInPoints((short) 12);
    
    headFont.setFontName("Microsoft YaHei UI Light");
    
    // 把字体应用到当前的样式
    
    headStyle.setFont(headFont);

    return headStyle;
    
    }

  /**

  • 判断文件是否存在
  • @param file
    
    */
    
    public static void judeFileExists(File file) {
    
    if (!file.exists()) {
    
    try {
    
    file.createNewFile();
    
    } catch (IOException e) {
    
    e.printStackTrace();
    
    }
    
    }
    
    }

  /**

  • 使用 Map按key进行排序
  • @param map
  • @return
    
    */
    
    public static Map

}

- 测试用例

package test.cmos;

import java.io.File;

import java.io.IOException;

import java.util.ArrayList;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import org.junit.Test;

import com.cmos.utils.ExcelData;

import com.cmos.utils.ExcelData.Head;

import com.cmos.utils.ExcelUtil;

public class ExcelTest{

//模拟数据量
static int dataSize = 500000;

@Test
public void testExport() throws IOException {
    ExcelData data = createData();
    new ExcelUtil().export(data, new File("E:/data.xlsx"));
}

/**
 * 模拟生成数据
 * @return
 */
private static ExcelData createData() {
    long a = System.currentTimeMillis();
    ExcelData data = new ExcelData();
    data.setTitle("商户对账差异明细");
    Map<String, String> c = new HashMap<String, String>();
    c.put("来源系统", "10085销售订单");
    c.put("对账日期", "2016-11-03到2016-11-05");
    c.put("商户", "华为");
    data.setCondition(c);
    List<Head> headList = new ArrayList<Head>();
    headList.add(new Head("来源系统", "a"));
    headList.add(new Head("批次号", "b"));
    headList.add(new Head("商户编号", "c"));
    headList.add(new Head("商户名称", "d"));
    headList.add(new Head("业务日期", "e"));
    headList.add(new Head("订单号", "f"));
    headList.add(new Head("我方金额", "g"));
    headList.add(new Head("对方金额", "h"));
    headList.add(new Head("差额", "i"));
    data.setHeadList(headList);

    List<Map<String, Object>> dataList = new ArrayList<Map<String, Object>>();
    for (int i = 0; i < dataSize; i++) {
        Map<String, Object> map = new HashMap<String, Object>();
        map.put("a", "a" + i);
        map.put("b", "b" + i);
        map.put("c", "c" + i);
        map.put("d", "d" + i);
        map.put("e", "e" + i);
        map.put("f", "f" + i);
        map.put("g", "g" + i);
        map.put("h", "h" + i);
        map.put("i", "i" + i);
        dataList.add(map);
    }
    data.setDataList(dataList);
    long b = System.currentTimeMillis();
    System.out.println("create data:"+(b-a)+"ms");
    return data;
}

}

- 传入的导出对象

package com.cmos.utils;

import java.util.List;

import java.util.Map;

public class ExcelData {

//标题

private String title;

//查询条件

private Map

public String getTitle() {
    return title;
}
public void setTitle(String title) {
    this.title = title;
}

public List<Head> getHeadList() {
    return headList;
}
public void setHeadList(List<Head> headList) {
    this.headList = headList;
}
public List<Map<String, Object>> getDataList() {
    return dataList;
}
public void setDataList(List<Map<String, Object>> dataList) {
    this.dataList = dataList;
}
public Map<String, String> getCondition() {
    return condition;
}
public void setCondition(Map<String, String> condition) {
    this.condition = condition;
}

public static class Head{
    private String name;
    private String column;
    public Head(){
    }
    public Head(String name,String column){
        this.name = name;
        this.column = column;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getColumn() {
        return column;
    }
    public void setColumn(String column) {
        this.column = column;
    }

}

}

```