使用若依vue写一个excel上传至数据库的代码

好的，下面是使用若依vue和Spring Boot实现Excel上传至数据库的代码：

1. 前端代码（Vue.js）

<template>
  <div>
    <el-upload
      class="upload-excel"
      action="/api/uploadExcel"
      :on-success="handleSuccess"
      :headers="{ 'Content-Type': 'multipart/form-data' }"
      :before-upload="beforeUpload"
      :auto-upload="false"
    >
      <el-button type="primary">上传Excel</el-button>
    </el-upload>
  </div>
</template>

<script>
export default {
  methods: {
    beforeUpload(file) {
      const isExcel = file.type === 'application/vnd.ms-excel' || file.type === 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet';
      if (!isExcel) {
        this.$message.error('只能上传Excel文件');
        return false;
      }
    },
    handleSuccess(response) {
      if (response.code === 200) {
        this.$message.success('上传成功');
      } else {
        this.$message.error('上传失败');
      }
    }
  }
}
</script>

2. 后端代码（Spring Boot）

@RestController
@RequestMapping("/api")
public class ExcelController {

  @Autowired
  private ExcelService excelService;

  @PostMapping("/uploadExcel")
  public ResponseEntity<?> uploadExcel(@RequestParam("file") MultipartFile file) {
    try {
      excelService.saveExcel(file);
      return ResponseEntity.ok().build();
    } catch (Exception e) {
      return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).build();
    }
  }
}

@Service
public class ExcelService {

  @Autowired
  private ExcelRepository excelRepository;

  public void saveExcel(MultipartFile file) throws Exception {
    List<ExcelEntity> entities = ExcelUtils.readExcel(file.getInputStream(), ExcelEntity.class);
    excelRepository.saveAll(entities);
  }
}

@Entity
@Table(name = "excel")
public class ExcelEntity {

  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  private Long id;

  @Column(name = "name")
  private String name;

  @Column(name = "age")
  private Integer age;

  // getters and setters
}

public interface ExcelRepository extends JpaRepository<ExcelEntity, Long> {

}

3. ExcelUtils.java（用于读取Excel文件并转换为实体类）

public class ExcelUtils {

  public static <T> List<T> readExcel(InputStream inputStream, Class<T> clazz) throws Exception {
    Workbook workbook = new XSSFWorkbook(inputStream);
    Sheet sheet = workbook.getSheetAt(0);

    List<T> list = new ArrayList<>();
    for (int i = 1; i <= sheet.getLastRowNum(); i++) {
      Row row = sheet.getRow(i);

      T entity = clazz.newInstance();
      for (int j = 0; j < row.getLastCellNum(); j++) {
        Cell cell = row.getCell(j);
        Field field = clazz.getDeclaredField(getFieldName(j));
        field.setAccessible(true);

        if (String.class == field.getType()) {
          field.set(entity, cell.getStringCellValue());
        } else if (Integer.class == field.getType()) {
          field.set(entity, (int) cell.getNumericCellValue());
        }
      }

      list.add(entity);
    }

    return list;
  }

  private static String getFieldName(int index) {
    switch (index) {
      case 0:
        return "name";
      case 1:
        return "age";
      default:
        return null;
    }
  }
}

需要注意的是，若依框架中使用的是Element UI组件库，因此前端代码中使用了Element UI的上传组件。