目录
2.2 使用POI高级版功能(SXSSFWorkbook) V3.8版本以上
1、使用场景
因为最近项目需要，有一个培训系统之中，培训任务下有3000多用户；以前开发这个导出方式使用POI,基础功能创建的导出功能函数。最后导致这个导出功能导出3000多条记录需要耗时26s(秒)。于是产品经理要求改善一下这块内容。因为我们项目之中针对Excel导出这块，由两位同事有两种实现方式。方式一：使用常规的POI创建Excel信息，最后执行导出。方式二：另外一个同事使用的自己封装一个模板方式导出Excel。另外同事感觉可以通过模板导出方式能够解决此问题。最后在他要求下修改为模板实现方式。最后虽然解决可以导出数据问题但是导出速度还是极其慢，耗时长达26s。最近寻求网上解决方案；于是候选一下三种方案：
- 使用POI高级版功能(SXSSFWorkbook) V3.8版本以上
- 使用国内开源工具包Hutools
- 使用EasyExcel进行测试
2、代码实现
针对以上三种方案我选择使用同样的导出数据结构和记录数量；分别采样数据是1w、10w、100w数据进行导出测测试发现三种实现效果差别不大，这部分数据在成果展现部分进行说明。下面分别针对以上三种方案代码实现。
2.1 引入的jar maven配置
<!--XSSFSheet相关-->
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>4.1.2</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>4.1.2</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml-schemas</artifactId>
<version>4.1.2</version>
</dependency>
<dependency>
<groupId>xerces</groupId>
<artifactId>xercesImpl</artifactId>
<version>2.12.0</version>
</dependency>
<dependency>
<groupId>cn.hutool</groupId>
<artifactId>hutool-all</artifactId>
<version>5.4.0</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>easyexcel</artifactId>
<version>2.2.6</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.12</version>
<scope>provided</scope>
</dependency>2.2 使用POI高级版功能(SXSSFWorkbook) V3.8版本以上
import org.apache.poi.hssf.usermodel.HSSFRichTextString;
import org.apache.poi.ss.usermodel.Cell;
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.xssf.streaming.SXSSFWorkbook;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.OutputStream;
import java.net.URLEncoder;
import java.util.List;
import java.util.Map;
/**
* Excel导出数据读取大数据量测试
*/
public class ExcelPoiUtil {
private static String generateFileNameByDataTotal(int dataTotal){
String excelFileName="导出数据总记录";
int recordCount=0;
if(dataTotal<=1000){
excelFileName+="1K条";
}else if(dataTotal>1000&&dataTotal<=10000){
recordCount=dataTotal/1000;
excelFileName+=recordCount+"K条";
}else if(dataTotal>10000&&dataTotal<=100000){
recordCount=dataTotal/10000;
excelFileName+=recordCount+"W条";
}else if(dataTotal>100000&&dataTotal<=1000000){
recordCount=dataTotal/10000;
excelFileName+=recordCount+"W条";
}
return excelFileName;
}
/**
* 使用POI 3.8 以上版本 SXSSFWorkbook 导出大数据量数据到Excel之中
* @param dataTotal
* @throws IOException
*/
public static void exportExcelBySXSSFWorkbook(HttpServletRequest request, HttpServletResponse response, int dataTotal) throws IOException {
long startTime =System.currentTimeMillis();
String recordFileName="SXSSF_POI导出Excel_"+generateFileNameByDataTotal(dataTotal);
Workbook wb = new SXSSFWorkbook(100); // keep 100 rows in memory, exceeding rows will be flushed to disk
Sheet sh = wb.createSheet();
List<Map<String, Object>> dataList=ExcelHuToolsUtil.getBigRowsDataMap(dataTotal);
Row rowHeader = sh.createRow(0);
String[] headers=new String[]{"姓名","年龄","成绩","是否合格","考试日期"};
for (int i = 0; i < headers.length; i++) {
Cell cell = rowHeader.createCell(i);
HSSFRichTextString text = new HSSFRichTextString(headers[i]);
cell.setCellValue(text);
}
for(int rownum = 0; rownum < dataList.size(); rownum++){
Row row = sh.createRow(rownum+1);
Map<String, Object> cellMap=dataList.get(rownum);
int cellIndex=0;
for (Map.Entry<String, Object> m : cellMap.entrySet()) {
//System.out.println("key:" + m.getKey() + " value:" + m.getValue());
Cell cell = row.createCell(cellIndex);
cell.setCellValue(m.getValue().toString());
cellIndex++;
}
}
OutputStream os = null; //文件输出流
String fileName = recordFileName+".xlsx";
try {
os = response.getOutputStream(); //重点突出输出到浏览器
//解决浏览器兼容问题
if (request.getHeader("User-Agent").toLowerCase().indexOf("firefox") > 0) {
fileName = new String(fileName.getBytes("GB2312"),"ISO-8859-1");
} else {
// 对文件名进行编码处理中文问题
fileName = java.net.URLEncoder.encode(fileName, "UTF-8");// 处理中文文件名的问题
fileName= new String(fileName.getBytes("UTF-8"), "GBK");// 处理中文文件名的问题
}
response.reset();
response.setContentType("application/vnd.ms-excel;charset=utf-8");
response.setHeader("Content-Disposition", "attachment; filename="+ URLEncoder.encode(recordFileName, "UTF-8")+".xlsx");//中文名称需要特殊处理
wb.write(os);
} catch (Exception e) {
}finally {
try {
if(os != null){
os.flush();
os.close();
os = null;
}
} catch (Exception e) {
}
}
long endTime=System.currentTimeMillis();
String exportRecord="";
int recordCount=0;
if(dataTotal<=1000){
exportRecord+="1K条";
}else if(dataTotal>1000&&dataTotal<=10000){
recordCount=dataTotal/1000;
exportRecord+=recordCount+"K条";
}else if(dataTotal>10000&&dataTotal<=1000000){
recordCount=dataTotal/10000;
exportRecord+=recordCount+"W条";
}
System.out.println("导出"+exportRecord+" 数据 耗时: "+(endTime-startTime)/1000 +" 秒");
}
}2.3 使用国内开源工具包Hutools实现
import cn.hutool.core.date.DateUtil;
import cn.hutool.core.util.RandomUtil;
import cn.hutool.poi.excel.ExcelUtil;
import cn.hutool.poi.excel.ExcelWriter;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.ByteArrayOutputStream;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
/**
* 使用hutool工具导出大数据量验证
*/
public class ExcelHuToolsUtil {
private static Logger logger = LoggerFactory.getLogger(ExcelHuToolsUtil.class);
public static List<Map<String, Object>> getBigRowsDataMap(int dataTotal){
List<Map<String, Object>> dataList=new ArrayList<>();
for(int i=0;i<dataTotal;i++){
Map<String, Object> rowData = new LinkedHashMap<>();
rowData.put("name", "name_"+(i+1));
rowData.put("age", RandomUtil.randomInt(22,100));
rowData.put("score", RandomUtil.randomDouble(85,100));
rowData.put("pass", i/2==0?true:false);
rowData.put("testDate", DateUtil.date());
dataList.add(rowData);
}
return dataList;
}
public static void exportExcelByHuTools(HttpServletRequest request, HttpServletResponse response, int dataTotal){
long startTime=System.currentTimeMillis();
String recordFileName="HuTools导出Excel_"+generateFileNameByDataTotal(dataTotal);
//通过工具类创建writer
try {
ExcelWriter writer =ExcelUtil.getBigWriter();
writer.renameSheet("HuTools导出大数据"); //甚至sheet的名称
//设置head的名称， 此时的顺寻就是导出的顺序， key就是RecordInfoDetailsDTO的属性名称， value就是别名
writer.addHeaderAlias("name", "姓名");
writer.addHeaderAlias("age", "年龄");
writer.addHeaderAlias("score", "成绩");
writer.addHeaderAlias("pass", "是否合格");
writer.addHeaderAlias("testDate", "考试日期");
//跳过当前行，既第一行，非必须，在此演示用
//writer.passCurrentRow();
List<Map<String, Object>> rowList= getBigRowsDataMap(dataTotal);
writer.write(rowList, true);
writer.setOnlyAlias(true);
response.reset();
response.setContentType("application/vnd.ms-excel;charset=utf-8");
response.setHeader("Content-Disposition", "attachment; filename="+ URLEncoder.encode(recordFileName, "UTF-8")+".xlsx");
//中文名称需要特殊处理
writer.flush(response.getOutputStream());
writer.close();
String exportRecord="";
int recordCount=0;
if(dataTotal<=1000){
exportRecord+="1K条";
}else if(dataTotal>1000&&dataTotal<=10000){
recordCount=dataTotal/1000;
exportRecord+=recordCount+"K条";
}else if(dataTotal>10000&&dataTotal<=1000000){
recordCount=dataTotal/10000;
exportRecord+=recordCount+"W条";
}
long endTime=System.currentTimeMillis();
System.out.println("hutool 写入 "+exportRecord+" 记录耗时 "+(endTime-startTime)/1000 +"秒");
}catch (Exception e) {
//如果导出异常，则生成一个空的文件
logger.info("######导出 excel异常 ：{}",e.getMessage());
try (ByteArrayOutputStream outputStream2 = new ByteArrayOutputStream()) {
Workbook workbook = new XSSFWorkbook();
workbook.createSheet("生成数据异常");
StringBuilder fileName = new StringBuilder(recordFileName).append(".xlsx");
workbook.write(outputStream2);
outputStream2.flush();
//AasExcelUtils.export(request, response, outputStream2.toByteArray(), fileName.toString());
}catch (Exception e2) {}
}
}
private static String generateFileNameByDataTotal(int dataTotal){
String excelFileName="导出数据总记录";
int recordCount=0;
if(dataTotal<=1000){
excelFileName+="1K条";
}else if(dataTotal>1000&&dataTotal<=10000){
recordCount=dataTotal/1000;
excelFileName+=recordCount+"K条";
}else if(dataTotal>10000&&dataTotal<=100000){
recordCount=dataTotal/10000;
excelFileName+=recordCount+"W条";
}else if(dataTotal>100000&&dataTotal<=1000000){
recordCount=dataTotal/10000;
excelFileName+=recordCount+"W条";
}
return excelFileName;
}
}2.4 使用EasyExcel进行测试代码
import com.alibaba.excel.annotation.ExcelIgnore;
import com.alibaba.excel.annotation.ExcelProperty;
import lombok.Data;
import java.util.Date;
/**
* 基础数据类
*
* @author Jiaju Zhuang
**/
@Data
public class DownloadData {
@ExcelProperty("姓名")
private String name;
@ExcelProperty("年龄")
private Integer age;
@ExcelProperty("成绩")
private Double score;
@ExcelProperty("考试日期")
private Date testDate;
@ExcelProperty("是否合格")
private Boolean pass;
/**
* 忽略这个字段
*/
@ExcelIgnore
private String ignore;
}
import cn.hutool.core.date.DateUtil;
import cn.hutool.core.util.RandomUtil;
import com.alibaba.excel.EasyExcel;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.List;
/**
* 使用EasyExcel导出数据
*/
public class ExcelEasyExcelUtil {
public static List<DownloadData> getBigRowsDataMap(int dataTotal){
List<DownloadData> dataList=new ArrayList<DownloadData>();
for(int i=0;i<dataTotal;i++){
DownloadData dataObj = new DownloadData();
dataObj.setName("name_"+(i+1));
dataObj.setAge(RandomUtil.randomInt(22,100));
dataObj.setScore(RandomUtil.randomDouble(85,100));
dataObj.setPass(i/2==0?true:false);
dataObj.setTestDate(DateUtil.date());
dataList.add(dataObj);
}
return dataList;
}
private static String generateFileNameByDataTotal(int dataTotal){
String excelFileName="导出数据总记录";
int recordCount=0;
if(dataTotal<=1000){
excelFileName+="1K条";
}else if(dataTotal>1000&&dataTotal<=10000){
recordCount=dataTotal/1000;
excelFileName+=recordCount+"K条";
}else if(dataTotal>10000&&dataTotal<=100000){
recordCount=dataTotal/10000;
excelFileName+=recordCount+"W条";
}else if(dataTotal>100000&&dataTotal<=1000000){
recordCount=dataTotal/10000;
excelFileName+=recordCount+"W条";
}
return excelFileName;
}
public static void exportExcelByEasyExcel(HttpServletRequest request, HttpServletResponse response, int dataTotal) throws IOException {
long startTime=System.currentTimeMillis();
String recordFileName="EasyExcel导出Excel_"+generateFileNameByDataTotal(dataTotal);
// 这里注意 有同学反应使用swagger 会导致各种问题，请直接用浏览器或者用postman
response.setContentType("application/vnd.ms-excel");
response.setCharacterEncoding("utf-8");
// 这里URLEncoder.encode可以防止中文乱码 当然和easyexcel没有关系
String fileName = URLEncoder.encode(recordFileName, "UTF-8");
response.setHeader("Content-disposition", "attachment;filename=" + fileName + ".xlsx");
EasyExcel.write(response.getOutputStream(), DownloadData.class).sheet("EasyExcel导出").doWrite(getBigRowsDataMap(dataTotal));
long endTime=System.currentTimeMillis();
String exportRecord="";
int recordCount=0;
if(dataTotal<=1000){
exportRecord+="1K条";
}else if(dataTotal>1000&&dataTotal<=10000){
recordCount=dataTotal/1000;
exportRecord+=recordCount+"K条";
}else if(dataTotal>10000&&dataTotal<=1000000){
recordCount=dataTotal/10000;
exportRecord+=recordCount+"W条";
}
System.out.println("EasyExcel导出"+exportRecord+" 数据 耗时: "+(endTime-startTime)/1000 +" 秒");
}
}3、成果展现
4、总结
最后因为系统以前引入的POI版本相对较低是3.9版本的；受限于其他功能之中用到低版本一些方法和属性，没有使用Hutool进行实现，刚好高于3.8版可以使用HSSFWorkbook以及SXSSFWorkbook，HSSFWorkbook用来处理较少的数据量，SXSSFWorkbook用来处理大数据量以及超大数据量的导出。于是选择使用第1种方式实现导出功能。最后效果很惊人。实现3000多条数据1秒导出。以下截图是调整前和调整后的效果。
若导出数据量确实多大，已经试过数据模型不太多情况下100w条记录，Excel文件大小已达33M，建议可以采取分隔数据模式导出为多个Excel文件。可见参考文章
我们在实际开发实践之中；虽然可以有多种实现方式；但是最后选择实现方式受限于环境因素；如同生活之中有很多选择，单最后能够达到不破不立的情况太少。所以需要选择一种适合具体场景的方式。
通过本次实践，这种导入导出功能十分常见，可以在实际项目之中采取抽取出可以导出大数据量实现工具类，统一一下导入导出部分功能工具，实现功能单一职责原则。国人这块能够思考和实践太少啦，导致每天都是堆码。