springboot 实现excel 批量导入导出

好的，我来为你解答这个问题。首先，需要在pom.xml文件中引入相关的依赖，如下所示：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>easyexcel</artifactId>
    <version>2.1.7</version>
</dependency>

然后，需要定义导入导出的相关接口和实现类。例如，定义一个ExcelUtil类，实现导出Excel文件的逻辑：

@Service
public class ExcelUtil {
    public void exportExcel(HttpServletResponse response, List<?> list, String fileName, String sheetName, Class<?> clazz) {
        ExcelWriter writer = null;
        try {
            response.setContentType("application/vnd.ms-excel");
            response.setCharacterEncoding("utf-8");
            response.setHeader("Content-disposition", "attachment;filename=" + URLEncoder.encode(fileName, "UTF-8"));
            OutputStream os = response.getOutputStream();
            writer = EasyExcel.write(os, clazz).build();
            WriteSheet sheet = EasyExcel.writerSheet(sheetName).build();
            writer.write(list, sheet);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (writer != null) {
                writer.finish();
            }
        }
    }
}

接下来，实现导入Excel文件的逻辑。例如，定义一个UserController类，实现导入Excel文件的接口：

@RestController
@RequestMapping("/user")
public class UserController {
    @Autowired
    private UserService userService;

    @PostMapping("/import")
    public void importExcel(@RequestParam("file") MultipartFile file) {
        try {
            InputStream inputStream = file.getInputStream();
            AnalysisEventListener<User> listener = new UserListener(userService);
            ExcelReader excelReader = EasyExcel.read(inputStream, User.class, listener).build();
            ReadSheet readSheet = EasyExcel.readSheet(0).build();
            excelReader.read(readSheet);
            excelReader.finish();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

其中，UserListener是实现了AnalysisEventListener接口的监听器类，用于处理读取Excel文件后的数据。具体实现可以参考以下代码：

public class UserListener extends AnalysisEventListener<User> {
    private UserService userService;

    public UserListener(UserService userService) {
        this.userService = userService;
    }

    private static final int BATCH_COUNT = 5;
    List<User> list = new ArrayList<>();

    @Override
    public void invoke(User user, AnalysisContext analysisContext) {
        list.add(user);
        if (list.size() >= BATCH_COUNT) {
            saveData();
            list.clear();
        }
    }

    @Override
    public void doAfterAllAnalysed(AnalysisContext analysisContext) {
        saveData();
    }

    private void saveData() {
        userService.saveBatch(list);
    }
}

以上就是使用Spring Boot实现Excel批量导入导出的基本流程。当然，具体实现还需要根据自己的业务需求进行调整。希望这些代码能够对你有所帮助。