SpringBoot中EasyExcel实现Excel文件的导入导出
前言
在我们日常的开发过程中经常会使用Excel
文件的形式来批量地上传下载系统数据,我们最常用的工具是Apache poi
,但是如果数据到底上百万时,将会造成内存溢出的问题,那么我们怎么去实现百万数据批量导入导出。
正文
Easyexcel
Easyexcel 是阿里巴巴的开源项目,用来优化Excel
文件处理过程:
- poi消耗内存严重:Java解析、生成
Excel
比较有名的框架有Apache poi
、jxl
。但他们都存在一个严重的问题就是非常的耗内存,poi
有一套SAX
模式的API
可以一定程度的解决一些内存溢出的问题,但poi
还是有一些缺陷,比如07版Excel
解压缩以及解压后存储都是在内存中完成的,内存消耗依然很大。 - easyexcel针对内存做出了优化:重写了
poi
对07版Excel
的解析,能够原本一个3M的excel
用POI sax
依然需要100M左右内存降低到几M,并且再大的excel
不会出现内存溢出。
SpringBoot+ EasyExcel实现Excel文件的导入导出
导入依赖
<!--lombok--> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <version>1.18.2</version> <optional>true</optional> </dependency> <!--easyExcel--> <dependency> <groupId>com.alibaba</groupId> <artifactId>easyexcel</artifactId> <version>1.1.2-beat1</version> </dependency> <!--fastjson--> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <exclusions> <exclusion> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-annotations</artifactId> </exclusion> </exclusions> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-annotations</artifactId> </dependency>
为了防止Excel文件被破坏在pom.xml
添加以下内容
<build> <plugins> <!-- 让maven不编译xls文件,但仍将其打包 --> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-resources-plugin</artifactId> <configuration> <nonFilteredFileExtensions> <nonFilteredFileExtension>xls</nonFilteredFileExtension> <nonFilteredFileExtension>xlsx</nonFilteredFileExtension> </nonFilteredFileExtensions> </configuration> </plugin> </plugins> </build>
application.propertis:配置文件
#temp files project.tmp.files.path=/Users/mac/Desktop/image/tmp/files/
在SpringBoot启动类添加临时文件设置
@Value("${project.tmp.files.path}") public String filesPath; @Bean MultipartConfigElement multipartConfigElement() { MultipartConfigFactory factory = new MultipartConfigFactory(); //设置路径xxx factory.setLocation(filesPath); return factory.createMultipartConfig(); }
ExcelUtil:Excel工具类
@Slf4j public class ExcelUtil { private static Sheet initSheet; static { initSheet = new Sheet(1, 0); initSheet.setSheetName("sheet"); //设置自适应宽度 initSheet.setAutoWidth(Boolean.TRUE); } public static void downLoadExcel(String fileName, HttpServletResponse response, Workbook workbook) { try { response.setCharacterEncoding("UTF-8"); response.setContentType("application/octet-stream;charset=utf-8"); response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName, "UTF-8")); workbook.write(response.getOutputStream()); } catch (IOException e) { // throw new NormalException(e.getMessage()); } } /** * 读取少于1000行数据 * * @param filePath 文件绝对路径 * @return */ public static List<Object> readLessThan1000Row(String filePath) { return readLessThan1000RowBySheet(filePath, null); } /** * 读小于1000行数据, 带样式 * filePath 文件绝对路径 * initSheet : * sheetNo: sheet页码,默认为1 * headLineMun: 从第几行开始读取数据,默认为0, 表示从第一行开始读取 * clazz: 返回数据List<Object> 中Object的类名 */ public static List<Object> readLessThan1000RowBySheet(String filePath, Sheet sheet) { if (!StringUtils.hasText(filePath)) { return null; } sheet = sheet != null ? sheet : initSheet; InputStream fileStream = null; try { fileStream = new FileInputStream(filePath); return EasyExcelFactory.read(fileStream, sheet); } catch (FileNotFoundException e) { log.info("找不到文件或文件路径错误, 文件:{}", filePath); } finally { try { if (fileStream != null) { fileStream.close(); } } catch (IOException e) { log.info("excel文件读取失败, 失败原因:{}", e); } } return null; } /** * 读大于1000行数据 * * @param filePath 文件觉得路径 * @return */ public static List<Object> readMoreThan1000Row(String filePath) { return readMoreThan1000RowBySheet(filePath, null); } /** * 读大于1000行数据, 带样式 * * @param filePath 文件觉得路径 * @return */ public static List<Object> readMoreThan1000RowBySheet(String filePath, Sheet sheet) { if (!StringUtils.hasText(filePath)) { return null; } sheet = sheet != null ? sheet : initSheet; InputStream fileStream = null; try { fileStream = new FileInputStream(filePath); ExcelListener excelListener = new ExcelListener(); EasyExcelFactory.readBySax(fileStream, sheet, excelListener); return excelListener.getDatas(); } catch (FileNotFoundException e) { log.error("找不到文件或文件路径错误, 文件:{}", filePath); } finally { try { if (fileStream != null) { fileStream.close(); } } catch (IOException e) { log.error("excel文件读取失败, 失败原因:{}", e); } } return null; } /** * 读大于1000行数据, 带样式 * * @return */ public static List<Object> readMoreThan1000RowBySheetFromInputStream(InputStream inputStream, Sheet sheet) { sheet = sheet != null ? sheet : initSheet; InputStream fileStream = null; ExcelListener excelListener = new ExcelListener(); EasyExcelFactory.readBySax(inputStream, sheet, excelListener); return excelListener.getDatas(); } /** * 生成excle * * @param filePath 绝对路径 * @param data 数据源 * @param head 表头 */ public static void writeBySimple(String filePath, List<List<Object>> data, List<String> head) { writeSimpleBySheet(filePath, data, head, null); } /** * 生成excle * * @param filePath 路径 * @param data 数据源 * @param sheet excle页面样式 * @param head 表头 */ public static void writeSimpleBySheet(String filePath, List<List<Object>> data, List<String> head, Sheet sheet) { sheet = (sheet != null) ? sheet : initSheet; if (head != null) { List<List<String>> list = new ArrayList<>(); head.forEach(h -> list.add(Collections.singletonList(h))); sheet.setHead(list); } OutputStream outputStream = null; ExcelWriter writer = null; try { outputStream = new FileOutputStream(filePath); writer = EasyExcelFactory.getWriter(outputStream); writer.write1(data, sheet); } catch (FileNotFoundException e) { log.error("找不到文件或文件路径错误, 文件:{}", filePath); } finally { try { if (writer != null) { writer.finish(); } if (outputStream != null) { outputStream.close(); } } catch (IOException e) { log.error("excel文件导出失败, 失败原因:{}", e); } } } /** * 生成excle * * @param filePath 路径 * @param data 数据源 */ public static void writeWithTemplate(String filePath, List<? extends BaseRowModel> data) { writeWithTemplateAndSheet(filePath, data, null); } /** * 生成excle * * @param filePath 路径 * @param data 数据源 * @param sheet excle页面样式 */ public static void writeWithTemplateAndSheet(String filePath, List<? extends BaseRowModel> data, Sheet sheet) { if (CollectionUtils.isEmpty(data)) { return; } sheet = (sheet != null) ? sheet : initSheet; sheet.setClazz(data.get(0).getClass()); OutputStream outputStream = null; ExcelWriter writer = null; try { outputStream = new FileOutputStream(filePath); writer = EasyExcelFactory.getWriter(outputStream); writer.write(data, sheet); } catch (FileNotFoundException e) { log.error("找不到文件或文件路径错误, 文件:{}", filePath); } finally { try { if (writer != null) { writer.finish(); } if (outputStream != null) { outputStream.close(); } } catch (IOException e) { log.error("excel文件导出失败, 失败原因:{}", e); } } } /** * 生成多Sheet的excle * * @param filePath 路径 * @param multipleSheelPropetys */ public static void writeWithMultipleSheel(String filePath, List<MultipleSheelPropety> multipleSheelPropetys) { if (CollectionUtils.isEmpty(multipleSheelPropetys)) { return; } OutputStream outputStream = null; ExcelWriter writer = null; try { outputStream = new FileOutputStream(filePath); writer = EasyExcelFactory.getWriter(outputStream); for (MultipleSheelPropety multipleSheelPropety : multipleSheelPropetys) { Sheet sheet = multipleSheelPropety.getSheet() != null ? multipleSheelPropety.getSheet() : initSheet; if (!CollectionUtils.isEmpty(multipleSheelPropety.getData())) { sheet.setClazz(multipleSheelPropety.getData().get(0).getClass()); } writer.write(multipleSheelPropety.getData(), sheet); } } catch (FileNotFoundException e) { log.error("找不到文件或文件路径错误, 文件:{}", filePath); } finally { try { if (writer != null) { writer.finish(); } if (outputStream != null) { outputStream.close(); } } catch (IOException e) { log.error("excel文件导出失败, 失败原因:{}", e); } } } /*********************匿名内部类开始,可以提取出去******************************/ @Data public static class MultipleSheelPropety { private List<? extends BaseRowModel> data; private Sheet sheet; } /** * 解析监听器, * 每解析一行会回调invoke()方法。 * 整个excel解析结束会执行doAfterAllAnalysed()方法 * * @author: chenmingjian * @date: 19-4-3 14:11 */ @Getter @Setter public static class ExcelListener extends AnalysisEventListener { private List<Object> datas = new ArrayList<>(); /** * 逐行解析 * object : 当前行的数据 */ @Override public void invoke(Object object, AnalysisContext context) { //当前行 // context.getCurrentRowNum() if (object != null) { datas.add(object); } } /** * 解析完所有数据后会调用该方法 */ @Override public void doAfterAllAnalysed(AnalysisContext context) { //解析结束销毁不用的资源 } } /************************匿名内部类结束,可以提取出去***************************/ }
CommonUtil:工具类
public class CommonUtil { /** * 生成32位编码,不含横线 * * @return uuid串 */ public static String getUUID() { String uuid = UUID.randomUUID().toString().trim().replaceAll("-", ""); return uuid.toUpperCase(); } /** * 得到当前日期格式化后的字符串,格式:yyyy-MM-dd(年-月-日) * @return 当前日期格式化后的字符串 */ public static String getTodayStr(){ return new SimpleDateFormat("yyyy-MM-dd").format(new Date()) ; } /** * 将对象转化成json * * @param t * @return * @throws JsonProcessingException */ public static <T> String toJson(T t) throws JsonProcessingException { return OBJECT_MAPPER.get().writeValueAsString(t); } }
UserPojoRes:实体类
@Setter @Getter @ToString public class UserPojoRes extends BaseRowModel implements Serializable { private static final long serialVersionUID = -2145503717390503506L; /** * 主键 */ @ExcelProperty(value = "ID", index = 0) private String id; /** * 姓名 */ @ExcelProperty(value = "用户名", index = 1) private String name; public UserPojoRes(String id, String name) { this.id = id; this.name = name; } public UserPojoRes(){ } }
验证
模板下载
这里将模板文件放在resources
中
@GetMapping("/exportExcelTempalte") @ApiOperation(value = "下载导入模板") public void exportExcelTempalte(HttpServletResponse response) throws Exception { //Resource目录中的文件 String filePath = "/excels/导入模板.xlsx"; ClassPathResource classPathResource = new ClassPathResource(filePath); Workbook workbook=WorkbookFactory.create(classPathResource.getInputStream()); ExcelUtil.downLoadExcel("导入模板.xlsx", response, workbook); }
Excel文件导入
@PostMapping("/importExcel") @ApiOperation(value = "Excel文件导入") public Response importExcel(HttpServletRequest request, MultipartFile file, HttpServletResponse response) throws Exception { List<Object> objects = ExcelUtil.readMoreThan1000RowBySheetFromInputStream(file.getInputStream(),null); List<UserPojoRes> list = new ArrayList<>(); for (Object o : objects) { UserPojoRes userPojoRes = new UserPojoRes(); List<String> stringList = (List<String>) o; userPojoRes.setId(stringList.get(0) != null ? stringList.get(0).toString() : ""); userPojoRes.setName(stringList.get(1) != null ? stringList.get(0).toString() : ""); list.add(userPojoRes); } String json = CommonUtil.toJson(list); return new Response(json); }
Excel文件导出
@Value("${project.tmp.files.path}") public String filesPath; @GetMapping("/exportExcel") @ApiOperation(value = "Excel文件导出") public void exportExcel(HttpServletResponse response) throws Exception { //创建临时文件 String path = filesPath + CommonUtil.getUUID() + ".xlsx"; List<UserPojoRes> list = new ArrayList<>(); UserPojoRes userPojoRes = new UserPojoRes("009", "张三"); UserPojoRes userPojoRes1 = new UserPojoRes("009", "李四"); list.add(userPojoRes); list.add(userPojoRes1); ExcelUtil.writeWithTemplate(path, list); // 根据excel创建对象 Workbook workbook = WorkbookFactory.create(new FileInputStream(path)); String fileName = "用户模块" + CommonUtil.getTodayStr() + ".xlsx"; ExcelUtil.downLoadExcel(fileName, response, workbook); }
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