我们实现导入/导出excel的第三方常用类库有 Apache poi、Java Excel（JXL）和阿里开源的 Easyexcel 等。我比较倾向使用Easyexcel，原因有两点：

1、性能强。有大量的数据去处理时，poi和jxl内存消耗比较大,可能造成内存溢出。

2、上手简单。poi是比较容易理解的，但是操作起来麻烦，比如我上一篇的“poi导入导出完整实现 包含工具类”，为了简单实现，代码写了好多。而easyexcel可以自己处理数据，样式也比较好调整。


如果你想更详细的学习easyexcel建议看官方文档


easyexcel导出

1、加入依赖


com.alibaba
easyexcel
2.0.4
compile


2、编写控制层

@GetMapping("/export")
@ResponseBody
public boolean export(HttpServletResponse response, HttpServletRequest request) {
boolean exportResult = testService.findInfo(response, request);
return exportResult;
}

3、编写实现层和导出实体类

boolean findInfo(HttpServletResponse response, HttpServletRequest request);


@Override
public boolean findInfo(HttpServletResponse response, HttpServletRequest request) {
try {
List> dataList = new ArrayList<>();
Map map = new HashMap<>();
map.put("id", "1");
map.put("name", "测试");
map.put("phone", "测试");
map.put("address", "测试");
map.put("enrolDate", "2021-12-11");
map.put("des", "测试");
Map map1 = new HashMap<>();
map1.put("id", "2");
map1.put("name", "测试1");
map1.put("phone", "测试1");
map1.put("address", "测试1");
map1.put("enrolDate", "2021-12-12");
map1.put("des", "测试1");
dataList.add(map);
dataList.add(map1);
List boList = dataList.stream().filter(Objects::nonNull)
.map(s -> TestBo.builder()
.id(Integer.valueOf(s.get("id")))
.name(s.get("name"))
.phone(s.get("phone"))
.address(s.get("address"))
.enrolDate(s.get("enrolDate"))
.des(s.get("des"))
.build()).collect(Collectors.toList());

//导出文件名称
String fileName = URLEncoder.encode("测试用户导出数据", "utf-8");
response.setHeader("Content-disposition", "attachment;filename=" + fileName + ".xlsx");
EasyExcel.write(response.getOutputStream(), TestBo.class).sheet("用户导出数据").doWrite(boList);
return true;
} catch (IOException e) {
e.printStackTrace();
return false;
}
}


@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder
/**设置 row 高度，不包含表头*/
@ContentRowHeight(25)
/**设置 表头 高度（与 @ContentRowHeight 相反）*/
@HeadRowHeight(25)
/**设置列宽*/
@ColumnWidth(25)
@Accessors(chain = true)

public class TestBo {
/**设置表头信息*/
@ExcelProperty("id")
private Integer id;

@ExcelProperty("姓名")
private String name;

@ExcelProperty("电话")
private String phone;

@ExcelProperty("地址")
private String address;

@ExcelProperty("时间")
private String enrolDate;

@ExcelProperty("备注")
private String des;

}

4、完成测试


easyexcel导入

1、编写控制层

@PostMapping(value = "/importExcel")
@ResponseBody
public boolean importExcel(@RequestParam("file") MultipartFile file) {
return testService.importData(file);
}


2、编写实现层和实体类


boolean importData(MultipartFile file);


@Override
@Transactional(rollbackFor = Exception.class)
public boolean importData(MultipartFile file) {
try {
List objectList =ExcelUtil.readMoreThan1000RowBySheetFromInputStream(file.getInputStream(),null,TestPo.class);
List poList=new ArrayList<>();
for (Object object:objectList) {
System.out.println(object);
TestPo po=new TestPo();
List srtList= (List) object;
po.setId(srtList.get(0)!=null?srtList.get(0).toString():"");
po.setName(srtList.get(1)!=null?srtList.get(1).toString():"");
po.setPhone(srtList.get(2)!=null?srtList.get(2).toString():"");
po.setAddress(srtList.get(3)!=null?srtList.get(3).toString():"");
po.setEnrolDate(srtList.get(4)!=null?srtList.get(4).toString():"");
po.setDes(srtList.get(5)!=null?srtList.get(5).toString():"");
poList.add(po);
}
return testDao.saveBatch(poList);
} catch (Exception e) {
e.printStackTrace();
return false;
}
}

//实体类
@Data
public class TestPo {
private String id;

private String name;

private String phone;

private String address;

private String enrolDate;

private String des;
}

实际开发业务不同入库方法我就不提供了，提供导入工具类

package com.example.mydemo1.util;

import com.alibaba.excel.context.AnalysisContext;
import com.alibaba.excel.event.AnalysisEventListener;

import java.util.ArrayList;
import java.util.List;

/**
* 解析监听器，
* 每解析一行会回调invoke()方法。
* 整个excel解析结束会执行doAfterAllAnalysed()方法
* @className ExcelListener
* @description easyexcel
* @date 2021/3/26 11:14
*/
public class ExcelListener extends AnalysisEventListener {
private List datas = new ArrayList();

public List getDatas() {
return datas;
}

public void setDatas(List datas) {
this.datas = datas;
}

/**
* 逐行解析
* object : 当前行的数据
*/
@Override
public void invoke(T object, AnalysisContext context) {
datas.add(object);
//当前行
// context.getCurrentRowNum()
/*if (object != null) {
datas.add((T) object);
}*/
}


/**
* 解析完所有数据后会调用该方法
*/
@Override
public void doAfterAllAnalysed(AnalysisContext context) {
//解析结束销毁不用的资源
}
}


//=============================================


package com.example.mydemo1.util;

import com.alibaba.excel.metadata.BaseRowModel;
import com.alibaba.excel.metadata.Sheet;
import lombok.Data;

import java.util.List;

/**
* @className MultipleSheelPropety
* @description easyexcel
* @date 2021/3/26 11:15
*/
@Data
public class MultipleSheelPropety {
private List data;
private Sheet sheet;
}


//=============================================


package com.example.mydemo1.util;

import com.alibaba.excel.EasyExcelFactory;
import com.alibaba.excel.ExcelWriter;
import com.alibaba.excel.metadata.BaseRowModel;
import com.alibaba.excel.metadata.Sheet;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.collections.CollectionUtils;
import org.apache.poi.ss.usermodel.Workbook;
import org.springframework.util.StringUtils;

import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

/**
* @className ExcelUtil
* @description easyexcel工具类
* @date 2021/3/26 11:10
*/
@Slf4j
public class ExcelUtil {
private static Sheet initSheet;


static {
initSheet = new Sheet(1, 0);
initSheet.setSheetName("sheet");
//设置自适应宽度
initSheet.setAutoWidth(Boolean.TRUE);
}

public static void downLoadExcel(String fileName, HttpServletResponse response, Workbook workbook) {
try {
response.setCharacterEncoding("UTF-8");
response.setContentType("application/octet-stream;charset=utf-8");
response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName, "UTF-8"));
workbook.write(response.getOutputStream());
} catch (IOException e) {
// throw new NormalException(e.getMessage());
}
}


/**
* 读取少于1000行数据
*
* @param filePath 文件绝对路径
* @return
*/
public static List readLessThan1000Row(String filePath) {
return readLessThan1000RowBySheet(filePath, null);
}




/**
* 读小于1000行数据, 带样式
* filePath 文件绝对路径
* initSheet ：
* sheetNo: sheet页码，默认为1
* headLineMun: 从第几行开始读取数据，默认为0, 表示从第一行开始读取
* clazz: 返回数据List 中Object的类名
*/
public static List readLessThan1000RowBySheet(String filePath, Sheet sheet) {
if (!StringUtils.hasText(filePath)) {
return null;
}
sheet = sheet != null ? sheet : initSheet;
InputStream fileStream = null;
try {
fileStream = new FileInputStream(filePath);
return EasyExcelFactory.read(fileStream, sheet);
} catch (FileNotFoundException e) {
log.info("找不到文件或文件路径错误, 文件：{}", filePath);
} finally {
try {
if (fileStream != null) {
fileStream.close();
}
} catch (IOException e) {
log.info("excel文件读取失败, 失败原因：{}", e);
}
}
return null;
}


/**
* 读大于1000行数据
*
* @param filePath 文件觉得路径
* @return
*/
public static List readMoreThan1000Row(String filePath) {
return readMoreThan1000RowBySheet(filePath, null);
}


/**
* 读大于1000行数据, 带样式
*
* @param filePath 文件觉得路径
* @return
*/
public static List readMoreThan1000RowBySheet(String filePath, Sheet sheet) {
if (!StringUtils.hasText(filePath)) {
return null;
}
sheet = sheet != null ? sheet : initSheet;
InputStream fileStream = null;
try {
fileStream = new FileInputStream(filePath);
ExcelListener excelListener = new ExcelListener();
EasyExcelFactory.readBySax(fileStream, sheet, excelListener);
return excelListener.getDatas();
} catch (FileNotFoundException e) {
log.error("找不到文件或文件路径错误, 文件：{}", filePath);
} finally {
try {
if (fileStream != null) {
fileStream.close();
}
} catch (IOException e) {
log.error("excel文件读取失败, 失败原因：{}", e);
}
}
return null;
}


/**
* 读大于1000行数据, 带样式
*
* @return
*/
public static List readMoreThan1000RowBySheetFromInputStream(InputStream inputStream, Sheet sheet,Class clazz) {
sheet = sheet != null ? sheet : initSheet;
InputStream fileStream = null;
ExcelListener excelListener = new ExcelListener();
EasyExcelFactory.readBySax(inputStream, sheet, excelListener);
/* ExcelReaderBuilder excelReaderBuilder=EasyExcelFactory.read(inputStream,clazz,excelListener);*/
return excelListener.getDatas();
}


/**
* 生成excle
*
* @param filePath 绝对路径
* @param data 数据源
* @param head 表头
*/
public static void writeBySimple(String filePath, List> data, List head) {
writeSimpleBySheet(filePath, data, head, null);
}


/**
* 生成excle
*
* @param filePath 路径
* @param data 数据源
* @param sheet excle页面样式
* @param head 表头
*/
public static void writeSimpleBySheet(String filePath, List> data, List head, Sheet sheet) {
sheet = (sheet != null) ? sheet : initSheet;
if (head != null) {
List> list = new ArrayList<>();
head.forEach(h -> list.add(Collections.singletonList(h)));
sheet.setHead(list);
}
OutputStream outputStream = null;
ExcelWriter writer = null;
try {
outputStream = new FileOutputStream(filePath);
writer = EasyExcelFactory.getWriter(outputStream);
writer.write1(data, sheet);
} catch (FileNotFoundException e) {
log.error("找不到文件或文件路径错误, 文件：{}", filePath);
} finally {
try {
if (writer != null) {
writer.finish();
}

if (outputStream != null) {
outputStream.close();
}

} catch (IOException e) {
log.error("excel文件导出失败, 失败原因：{}", e);
}
}
}


/**
* 生成excle
*
* @param filePath 路径
* @param data 数据源
*/
public static void writeWithTemplate(String filePath, List data) {
writeWithTemplateAndSheet(filePath, data, null);
}




/**
* 生成excle
*
* @param filePath 路径
* @param data 数据源
* @param sheet excle页面样式
*/
public static void writeWithTemplateAndSheet(String filePath, List data, Sheet sheet) {
if (CollectionUtils.isEmpty(data)) {
return;
}
sheet = (sheet != null) ? sheet : initSheet;
sheet.setClazz(data.get(0).getClass());
OutputStream outputStream = null;
ExcelWriter writer = null;
try {
outputStream = new FileOutputStream(filePath);
writer = EasyExcelFactory.getWriter(outputStream);
writer.write(data, sheet);
} catch (FileNotFoundException e) {
log.error("找不到文件或文件路径错误, 文件：{}", filePath);
} finally {
try {
if (writer != null) {
writer.finish();
}
if (outputStream != null) {
outputStream.close();
}
} catch (IOException e) {
log.error("excel文件导出失败, 失败原因：{}", e);
}
}




}




/**
* 生成多Sheet的excle
*
* @param filePath 路径
* @param multipleSheelPropetys
*/
public static void writeWithMultipleSheel(String filePath, List multipleSheelPropetys) {
if (CollectionUtils.isEmpty(multipleSheelPropetys)) {
return;
}
OutputStream outputStream = null;
ExcelWriter writer = null;
try {
outputStream = new FileOutputStream(filePath);
writer = EasyExcelFactory.getWriter(outputStream);
for (MultipleSheelPropety multipleSheelPropety : multipleSheelPropetys) {
Sheet sheet = multipleSheelPropety.getSheet() != null ? multipleSheelPropety.getSheet() : initSheet;
if (!CollectionUtils.isEmpty(multipleSheelPropety.getData())) {
sheet.setClazz(multipleSheelPropety.getData().get(0).getClass());
}
writer.write(multipleSheelPropety.getData(), sheet);
}

} catch (FileNotFoundException e) {
log.error("找不到文件或文件路径错误, 文件：{}", filePath);
} finally {
try {
if (writer != null) {
writer.finish();
}

if (outputStream != null) {
outputStream.close();
}
} catch (IOException e) {
log.error("excel文件导出失败, 失败原因：{}", e);
}
}
}

}

3、准备导入文件

本文中没有对导入文档做错误校验，建议在实际开发中为用户提供导入模板，可以减少错误的出现。


4、使用postman测试

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版权声明：本文为CSDN博主「窈岆瀮珊」的原创文章，遵循CC 4.0 BY-SA版权协议，转载请附上原文出处链接及本声明。

原文链接：

https://blog.csdn.net/weixin_53233637/article/details/114576212