EasyExcel是什么
EasyExcel是一个基于Java的、快速、简洁、解决大文件内存溢出的Excel处理工具。
他能让你在不用考虑性能、内存的等因素的情况下,快速完成Excel的读、写等功能。
相关网站
官网 easyexcel.opensource.alibaba.com/
GitHub github.com/alibaba/eas...
实现
pom依赖导入
xml
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>easyexcel</artifactId>
<version>3.3.2</version>
</dependency>
excel数据
一共包含姓名,手机号,性别,地址,状态,注册时间6列,共50条数据
数据库表结构
实体类User
kotlin
package com.example.springbootdemo.entity;
import com.baomidou.mybatisplus.annotation.*;
import com.example.springbootdemo.enums.GenderEnum;
import com.fasterxml.jackson.annotation.JsonFormat;
import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
import com.fasterxml.jackson.databind.annotation.JsonSerialize;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateTimeDeserializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateTimeSerializer;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;
import lombok.experimental.Accessors;
import java.io.Serializable;
import java.time.LocalDateTime;
/**
* <p>
* 用户实体类
* </p>
*
* @author yurenwei
* @since 2023/9/7
*/
@ApiModel(value = "用户参数", description = "用户参数")
@Data
@Accessors(chain = true)
@TableName("user")
public class User implements Serializable {
private static final long serialVersionUID = 1L;
/**
* 主键id
*/
@ApiModelProperty(value = "主键id")
@TableId(value = "id", type = IdType.ASSIGN_ID)
private Long id;
/**
* 姓名
*/
@ApiModelProperty(value = "姓名")
private String userName;
/**
* 手机号
*/
@ApiModelProperty(value = "手机号")
private String phone;
/**
* 性别
*/
@ApiModelProperty(value = "性别")
private GenderEnum gender;
/**
* 地址
*/
@ApiModelProperty(value = "地址")
private String address;
/**
* 状态(0、禁用1、启用)
*/
@ApiModelProperty(value = "状态(0、禁用1、启用)")
private Boolean status;
/**
* 注册时间
*/
@ApiModelProperty(value = "注册时间")
@JsonDeserialize(using = LocalDateTimeDeserializer.class)
@JsonSerialize(using = LocalDateTimeSerializer.class)
@JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss", timezone = "GMT+8")
private LocalDateTime registerTime;
/**
* 创建人
*/
@ApiModelProperty(value = "创建人")
private Long createBy;
/**
* 创建时间
*/
@ApiModelProperty(value = "创建时间")
@JsonDeserialize(using = LocalDateTimeDeserializer.class)
@JsonSerialize(using = LocalDateTimeSerializer.class)
@JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss", timezone = "GMT+8")
@TableField(fill = FieldFill.INSERT)
private LocalDateTime createTime;
/**
* 修改人
*/
@ApiModelProperty(value = "修改人")
private Long updateBy;
/**
* 修改时间
*/
@ApiModelProperty(value = "修改时间")
@JsonDeserialize(using = LocalDateTimeDeserializer.class)
@JsonSerialize(using = LocalDateTimeSerializer.class)
@JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss", timezone = "GMT+8")
@TableField(fill = FieldFill.INSERT_UPDATE)
private LocalDateTime updateTime;
/**
* 是否删除(0、否1、是)
*/
@ApiModelProperty(value = "是否删除(0、否1、是)")
private Boolean isDeleted;
}
controller导入方法
less
@ApiOperation("导入")
@PostMapping("/importUser")
public Result importUser(@RequestParam(value = "file") MultipartFile file){
userService.importUser(file);
return Result.ok();
}
service导入方法
scss
/**
* 导入excel
*
* @param file excel文件
*/
public void importUser(MultipartFile file) {
try {
EasyExcel.read(file.getInputStream(), UserExcelDTO.class, new UserExcelListener(iUserService))
.sheet(0)
.headRowNumber(1)
.doRead();
} catch (IOException e) {
log.error("导入用户数据异常:{}",e.getMessage());
e.printStackTrace();
}
}
excel对应实体类
kotlin
package com.example.springbootdemo.dto;
import com.alibaba.excel.annotation.ExcelProperty;
import com.alibaba.excel.annotation.format.DateTimeFormat;
import lombok.Data;
import java.io.Serializable;
import java.time.LocalDateTime;
/**
* <p>
* 用户excel实体类
* </p>
*
* @author yurenwei
* @since 2023/9/7
*/
@Data
public class UserExcelDTO implements Serializable {
private static final long serialVersionUID = 1L;
/**
* 姓名
*/
@ExcelProperty(value = "姓名",index = 0)
private String userName;
/**
* 手机号
*/
@ExcelProperty(value = "手机号",index = 1)
private String phone;
/**
* 性别
*/
@ExcelProperty(value = "性别",index = 2)
private String gender;
/**
* 地址
*/
@ExcelProperty(value = "地址",index = 3)
private String address;
/**
* 状态(0、禁用1、启用)
*/
@ExcelProperty(value = "状态",index = 4)
private String status;
/**
* 注册时间
*/
@ExcelProperty(value = "注册时间",index = 5)
@DateTimeFormat("yyyy-MM-dd HH:mm:ss")
private LocalDateTime registerTime;
}
此处注意# @Accessors(chain = true)与EasyExcel不兼容,不要增加此注解,要不导入数据为空
创建读取excel监听类
scss
package com.example.springbootdemo.listener;
import cn.hutool.core.util.IdUtil;
import com.alibaba.excel.context.AnalysisContext;
import com.alibaba.excel.read.listener.ReadListener;
import com.alibaba.excel.util.ListUtils;
import com.alibaba.fastjson.JSON;
import com.example.springbootdemo.dto.UserExcelDTO;
import com.example.springbootdemo.entity.User;
import com.example.springbootdemo.enums.GenderEnum;
import com.example.springbootdemo.mybatisplus.IUserService;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.collections4.CollectionUtils;
import java.util.List;
import java.util.stream.Collectors;
/**
* <p>
* 用户excel监听类
* </p>
*
* @author yurenwei
* @since 2023/9/7
*/
@Slf4j
public class UserExcelListener implements ReadListener<UserExcelDTO> {
/**
* 每隔10条数据存储数据库,然后清理List,方便内存回收
*
*/
private static final int BATCH_COUNT = 10;
/**
* 缓存的数据
*/
private List<UserExcelDTO> cacheList = ListUtils.newArrayListWithExpectedSize(BATCH_COUNT);
private IUserService iUserService;
public UserExcelListener(IUserService iUserService){
this.iUserService = iUserService;
}
/**
* 每一条数据解析都会调用
*
* @param user
* @param analysisContext
*/
@Override
public void invoke(UserExcelDTO user, AnalysisContext analysisContext) {
log.info("解析到一条数据user:{}", JSON.toJSONString(user));
cacheList.add(user);
// 达到BATCH_COUNT了,需要去存储一次数据库,防止数据几万条数据在内存,容易OOM
if(cacheList.size()>=BATCH_COUNT){
// 保存数据
saveData();
// 存储完成清理list
cacheList = ListUtils.newArrayListWithExpectedSize(BATCH_COUNT);
}
}
/**
* 所有数据都解析完了才会调用
*
* @param analysisContext
*/
@Override
public void doAfterAllAnalysed(AnalysisContext analysisContext) {
// 这里也要保存数据,确保最后遗留的数据也存储到数据库
saveData();
log.info("所有数据解析完成!");
}
/**
* 保存数据
*/
public void saveData(){
log.info("一共{}条数据,开始存储数据库!",cacheList.size());
if(CollectionUtils.isNotEmpty(cacheList)){
List<User> userList = cacheList.stream().map(item -> new User()
.setId(IdUtil.getSnowflakeNextId())
.setUserName(item.getUserName())
.setPhone(item.getPhone())
.setGender("男".equals(item.getGender())? GenderEnum.MALE:GenderEnum.FEMALE)
.setAddress(item.getAddress())
.setRegisterTime(item.getRegisterTime())
.setStatus("启用".equals(item.getStatus())))
.collect(Collectors.toList());
// 批量保存
iUserService.saveBatch(userList);
}
log.info("存储数据库成功!");
}
}
启动项目测试导入
控制台打印信息
查看数据库是否成功导入数据
可见50条都被成功导入到数据库表当中,并且数据都是正确的。
接下来实现导出
controller导出方法
less
@ApiOperation("导出")
@PostMapping("/export")
public void export(HttpServletResponse response){
userService.export(response);
}
service导出方法
scss
/**
* 导出
*
* @param response 响应
*/
public void export(HttpServletResponse response) {
// 查询所有用户
List<User> list = iUserService.list();
// 转换数据
List<UserExcelDTO> excelList = list.stream().map(item ->
{
UserExcelDTO user = new UserExcelDTO();
user.setUserName(item.getUserName());
user.setPhone(item.getPhone());
user.setGender(GenderEnum.MALE.equals(item.getGender())?"男":"女");
user.setAddress(item.getAddress());
user.setStatus(item.getStatus()?"启用":"禁用");
user.setRegisterTime(item.getRegisterTime());
return user;
})
.collect(Collectors.toList());
// 调用工具类导出
ExcelUtil.exportExcel("用户数据","用户",excelList,UserExcelDTO.class,response);
}
导出excel工具类
java
package com.example.springbootdemo.util;
import com.alibaba.excel.EasyExcel;
import com.alibaba.excel.support.ExcelTypeEnum;
import lombok.extern.slf4j.Slf4j;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.util.List;
/**
* <p>
* excel工具类
* </p>
*
* @author yurenwei
* @since 2023/9/14
*/
@Slf4j
public class ExcelUtil {
/**
* 导出excel
*
* @param fileName excel文件名称
* @param sheetName excel sheet名称
* @param list 数据
* @param clazz
* @param response
*/
public static void exportExcel(String fileName, String sheetName, List list, Class clazz, HttpServletResponse response){
ServletOutputStream outputStream;
try {
response.setContentType("application/vnd.ms-excel");
response.setCharacterEncoding("utf8");
response.setHeader("Content-Disposition", "attachment; filename=" + fileName + ".xlsx");
outputStream = response.getOutputStream();
EasyExcel.write(outputStream)
.head(clazz)
.excelType(ExcelTypeEnum.XLSX)
.sheet(sheetName)
.doWrite(list);
outputStream.flush();
} catch (Exception e) {
log.error("导出excel异常:{}",e.getMessage());
e.printStackTrace();
}
}
}
测试导出
下载excel文件查看
通过测试导出excel 列名和数据都正确
至此,SpringBoot整合EasyExcel实现导入导出完成了,通过整合测试发现,使用EasyExcel还是挺方便的。