EasyExcel

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。

引入依赖

 	<dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>easyexcel</artifactId>
        <version>3.1.3</version> 
    </dependency>

引入dozermapper依赖用于后续对象间类型转换

    <dependency>
        <groupId>com.github.dozermapper</groupId>
        <artifactId>dozer-spring-boot-starter</artifactId>
        <version>6.5.0</version>
    </dependency>

表结构

学生表

CREATE TABLE `student`  (
  `id` bigint UNSIGNED NOT NULL AUTO_INCREMENT COMMENT '学生表ID',
  `sname` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL COMMENT '学生姓名',
  `sno` bigint NOT NULL COMMENT '学号',
  `sex` char(2) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL COMMENT '性别',
  `age` int NOT NULL COMMENT '年龄',
  `is_deleted` tinyint UNSIGNED NOT NULL DEFAULT 0 COMMENT '是否删除',
  PRIMARY KEY (`id`)
);

项目结构

DozerUtils工具类

public class DozerUtils {
    public static <T,S> List<T> mapList(final Mapper mapper, List<S> sourceList, Class<T> targetObjectClass){
        List<T> targetList=new ArrayList<T>();
        for(S s:sourceList){
            targetList.add(mapper.map(s,targetObjectClass));
        }
        return targetList;
    }
}

实体类Student

@ExcelProperty(value =“该字段在Excel中的表头名称”）
@ExcelIgnore：解析时忽略该字段

@Data
public class Student {

    /**主键ID**/
    @ExcelIgnore
    private Long id;
    /**学生姓名**/
    @ExcelProperty(value = "姓名")
    private String sname;
    /**学号**/
    @ExcelProperty(value = "学号")
    private Long sno;
    /**性别**/
    @ExcelProperty(value = "性别")
    private String sex;
    /**年龄**/
    @ExcelProperty(value = "年龄")
    private Integer age;
    /**是否删除**/
    @ExcelIgnore
    private Integer isDeleted;

}

Controller

@RestController
@RequestMapping("/easyExcel")
public class EasyExcelController {

    @Resource
    private IStudentService studentService;

    @PostMapping("/studentInput")
    public void studentInput(MultipartFile file){
        studentService.studentInput(file);
    }

}

监听类

本次设置为1000条数据为一批导入，可根据实际情况调整为3000以内
本次导入未设置导入逻辑，如需设置逻辑，在监听类saveDate方法内调用按逻辑增加的service方法

@Data
public class StudentListener extends AnalysisEventListener<Student> {
    /**
     *单次缓存量为1000
     */
    private final int BATCH_SIZE = 1000;

    /**
     * 临时存储List
     */
    List<Student> cacheData = new ArrayList<Student>();
    private IStudentService studentService;
    private Mapper dozerMapper;

    public StudentListener(IStudentService studentService, Mapper dozerMapper){
        this.studentService = studentService;
        this.dozerMapper = dozerMapper;
    }
    @Override
    public void invoke(Student data, AnalysisContext analysisContext) {
        cacheData.add(data);
        if (cacheData.size() >= BATCH_SIZE){
            saveData();
            //每批存储完成后清空list
            cacheData.clear();
        }
    }

    @Override
    public void doAfterAllAnalysed(AnalysisContext analysisContext) {
        if (cacheData.size() > 0){
            saveData();
        }
    }

    /**
     * 加入数据库
     */
    private void saveData(){
        List<Student> students = DozerUtils.mapList(dozerMapper,cacheData,Student.class);
        studentService.saveBatch(students);
    }
}

Service

public interface IStudentService extends IService<Student> {
    void studentInput(MultipartFile file);
}

ServiceImpl

@Service
public class StudentServiceImpl extends ServiceImpl<StudentMapper, Student> implements IStudentService {
    
    @Resource
    private IStudentService studentService;
    @Resource
    private Mapper dozerMapper;
    
    @Override
    @Transactional(rollbackFor = Throwable.class)
    public void studentInput(MultipartFile file) {
        try {
            InputStream inputStream = file.getInputStream();
            EasyExcel.read(inputStream, Student.class,
                    new StudentListener(studentService, dozerMapper)).sheet().doRead();
        }catch (Exception e){
            e.printStackTrace();
        }
    }
}

mapper

public interface StudentMapper extends BaseMapper<Student> {
}

启动项目

测试

测试数据

注意列名文字与实体类对应字段注解中的文字相同

PostMan测试

form-data中设置格式为file

选择需要上传的测试文件

完成后查看数据库

导入成功