easypoi中上传文件方式excel导入

1. 引入easypoi和上传文件的依赖：

<!-- 引入easypoi -->
<dependency>
    <groupId>cn.afterturn</groupId>
    <artifactId>easypoi-base</artifactId>
    <version>4.2.0</version>
</dependency>
<!-- 文件上传依赖 -->
<dependency>
    <groupId>commons-fileupload</groupId>
    <artifactId>commons-fileupload</artifactId>
    <version>1.4</version>
</dependency>
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-io</artifactId>
    <version>1.3.2</version>
</dependency>

2. 创建一个Excel导入的POJO类，例如：

import cn.afterturn.easypoi.excel.annotation.Excel;
import lombok.Data;

@Data
public class UserExcelModel {
    @Excel(name = "姓名")
    private String name;
    @Excel(name = "年龄")
    private Integer age;
    @Excel(name = "性别")
    private String gender;
}

3. 创建Controller处理上传并导入Excel的请求：

import cn.afterturn.easypoi.excel.ExcelImportUtil;
import cn.afterturn.easypoi.excel.entity.ImportParams;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.io.FileUtils;
import org.apache.commons.io.IOUtils;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;

@Slf4j
@Controller
@RequestMapping("/excel")
public class ExcelController {

    @PostMapping("/import")
    public void importExcel(@RequestParam("file") MultipartFile file,
                            HttpServletResponse response) throws IOException {

        // 将MultipartFile转换为File
        File tempFile = File.createTempFile("temp", null);
        FileUtils.copyInputStreamToFile(file.getInputStream(), tempFile);

        // 导入Excel
        ImportParams importParams = new ImportParams();
        List<UserExcelModel> userList = ExcelImportUtil.importExcel(
                tempFile, UserExcelModel.class, importParams);

        // 做一些业务处理，例如将数据保存到数据库

        // 返回结果给前端
        response.setContentType("application/json;charset=UTF-8");
        response.getWriter().write("导入成功！");
    }
}

4. 在前端页面中添加一个文件上传表单，并将文件上传到Controller中：

<form action="/excel/import" method="post" enctype="multipart/form-data">
    <input type="file" name="file">
    <button type="submit">上传并导入</button>
</form>