EasyExcel导入导出excel 复杂表头表头校验数据校验

EasyExcel特点

一.导入excel案例

二.读取excel的相关技术点

1.读取excel的方式

2.读取sheet数量

3.指定从第几行开始读数据

三.导出excel

1.前端发起请求

2.controller控制层

3.service层

4.实体类：复杂表头的情况，给@ExcelProperty的value赋值时，需要具备所有行的表头；使用注解@ExcelIgnore忽略导出的字段是否包含

5.设置导出excel的表头高宽：加在类上或者字段上

EasyExcel特点

Java领域解析，生成Excel比较有名的框架有Apache poi,jxl等，但他们都存在一个严重的问题就是非常的耗内存，如果你的系统并发量不大的话可能还行，但是一旦并发上来后一定会OOM或者JVM频繁的full gc.

EasyExcel是阿里巴巴开源的一个excel处理框架，以使用简单，节省内存著称，EasyExcel能大大减少占用内存的主要原因是在解析Excel时没有将文件数据一次性全部加载到内存中，而是从磁盘上一行行读取数据，逐个解析。

EasyExcel采用一行一行的解析模式，并将一行的解析结果以观察者的模式通知处理（AnalysisEventListener）

如果在项目中已经使用了POI，再引入easyexcel可能会存在冲突，要注意对应的版本

     <!-- https://mvnrepository.com/artifact/org.apache.poi/poi --><dependency><groupId>org.apache.poi</groupId><artifactId>poi</artifactId><version>3.17</version></dependency><dependency><groupId>org.apache.poi</groupId><artifactId>poi-ooxml</artifactId><version>3.17</version></dependency><dependency><groupId>org.apache.poi</groupId><artifactId>poi-scratchpad</artifactId><version>3.17</version></dependency><!-- https://mvnrepository.com/artifact/com.alibaba/easyexcel --><dependency><groupId>com.alibaba</groupId><artifactId>easyexcel</artifactId><version>2.1.1</version></dependency>

一.导入excel案例

需求：校验导入excel表头是否正确，excel行转成实体对象出错时，获取错误信息

1.前端：使用bootstrap的fileinput控件，设置上传的链接及上传结束后的提示信息

$("#file").fileinput({            language : 'zh',         uploadUrl :basePath+"roadData/uploadExcelFileNew",                     maxFileCount : 10,//表示允许同时上传的最大文件个数showCaption : true,//是否显示标题browseClass : "btn btn-primary", //按钮样式showPreview:true,       allowedFileExtensions: ["xls", "xlsx"], uploadAsync:true,                  msgFilesTooLess:'您必须至少选择{n}个文件才能上传，请点击“浏览”选择您需要上传的文件！',msgFilesTooMany:'超过了单次上传最大文件数{m}个，请分批次上传！',previewFileIcon: '<i class="fa fa-file"></i>',browseLabel : "浏览",msgSelected:'添加了{n}个文件',   dropZoneTitle:'拖拽文件到这里 …<br/>最多支持10个文件上传<br/>',uploadExtraData:function (previewId, index) {    var data = {  "isClearFlag": mini.get("isClearFlag").getValue()};return data;     },previewFileIconSettings: {'doc': '<i class="fa fa-file-word-o text-primary"></i>','xls': '<i class="fa fa-file-excel-o text-success"></i>','ppt': '<i class="fa fa-file-powerpoint-o text-danger"></i>','jpg': '<i class="fa fa-file-photo-o text-warning"></i>','pdf': '<i class="fa fa-file-pdf-o text-danger"></i>','zip': '<i class="fa fa-file-archive-o text-muted"></i>','htm': '<i class="fa fa-file-code-o text-info"></i>','txt': '<i class="fa fa-file-text-o text-info"></i>','mov': '<i class="fa fa-file-movie-o text-warning"></i>','mp3': '<i class="fa fa-file-audio-o text-warning"></i>',}, layoutTemplates:{       //是否显示预览下的上传按钮      actionUpload:''},previewFileExtSettings: {'doc': function(ext) {return ext.match(/(doc|docx)$/i);},'xls': function(ext) {return ext.match(/(xls|xlsx)$/i);},'ppt': function(ext) {return ext.match(/(ppt|pptx)$/i);},'zip': function(ext) {return ext.match(/(zip|rar|tar|gzip|gz|7z)$/i);},'htm': function(ext) {return ext.match(/(php|js|css|htm|html)$/i);},'txt': function(ext) {return ext.match(/(txt|ini|md)$/i);},'mov': function(ext) {return ext.match(/(avi|mpg|mkv|mov|mp4|3gp|webm|wmv)$/i);},'mp3': function(ext) {return ext.match(/(mp3|wav)$/i);},}});   $("#file").on('fileuploaded', function(event, data, previewId, index) {var message = mini.decode(data);   if(message.response.type == 200){  showMsg("文件上传成功","success",1800,"center","center",closeWindow());    }else{showMsg(message.response.msg,"danger",3000,"center","center");}    });  function closeWindow(action) {if (window.CloseOwnerWindow) return window.CloseOwnerWindow(action);else window.close();              }

2.controller控制层：文件上传调用的方法

 /*** @Description 上传文件--使用easyexcel方式解析* @author qingyun* @Date 2021年5月19日 上午10:26:03*/@RequestMapping("/uploadExcelFileNew")  public String uploadExcelFileNew(@RequestParam("file") MultipartFile file, HttpServletRequest request,HttpServletResponse response) {return roadDataService.uploadExcelFileNew(file,request,response);  }

3.serice层：处理文件上传逻辑，这里定义一个工具类EasyExcelUtils进行处理，对处理结果根据Message标识判断是否解析正常，正常则设置其他字段值，把数据入库，不正常，则把message返回给前端

 /*** @Description 上传文件--使用easyexcel方式解析* @author qingyun* @Date 2021年5月19日 上午10:26:03*/public String uploadExcelFileNew(MultipartFile file, HttpServletRequest request, HttpServletResponse response) {Message message = new Message();EasyExcelUtils easyExcelUtils = new EasyExcelUtils(RoadData.class);  //创建工具类时传递class，用于后面比对表头使用try {request.setCharacterEncoding("utf-8");response.setCharacterEncoding("utf-8");InputStream fileInput = file.getInputStream(); // 输入流EasyExcel.read(fileInput,RoadData.class,easyExcelUtils).sheet().doRead();message = easyExcelUtils.getMessage();if(Message.OK == message.getType()) {   //解析完成没有错误List<Object> list = easyExcelUtils.getList();   //使用Object类型存放集合if (null != list && list.size() > 0) {List<GjArea> areaList = getGjArea();  //获取到所有的政区集合Date nowDate = new Date();SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");String nowDateStr = sdf.format(nowDate);List<RoadData> roadDataList = new ArrayList<RoadData>();for (int i = 0;i < list.size();i++) { //设置其他非excel字段的值RoadData roadData = (RoadData) list.get(i);roadData.setId(this.getUUID());roadData.setCreateTime(nowDate);roadData.setCreateUserCode(this.getUserCode());roadData.setCreateUserName(this.getUserEntity().getName());roadData.setUnit(formatUnit(roadData.getUnit(),areaList));roadData.setPci_score(RoadImportUtils.getPCIScore(roadData.getRoadGradeName(), String.valueOf(roadData.getPci()), String.valueOf(roadData.getPciAfter()),String.valueOf(roadData.getRepYear()),roadData.getRectificaFlag()));roadData.setRqi_score(RoadImportUtils.getRQIScore(roadData.getPaveTypeName(), String.valueOf(roadData.getRqi()), String.valueOf(roadData.getRqiAfter()),String.valueOf(roadData.getRepYear()),roadData.getRectificaFlag()));roadData.setRdi_score(RoadImportUtils.getRDIScore(roadData.getRoadGradeName(), roadData.getPaveTypeName(),String.valueOf(roadData.getRdi()), String.valueOf(roadData.getRdiAfter()),String.valueOf(roadData.getRepYear()),roadData.getRectificaFlag()));roadDataList.add(roadData);}String isClearFlag = request.getParameter("isClearFlag");if("true".equals(isClearFlag)) {   //先清除数据再插入,只清楚在这次之前添加的数据String hql = "delete FROM score.road_data WHERE  DATE_FORMAT(create_time, '%Y-%m-%d %H:%i:%s' ) < '"+nowDateStr+"' ";this.getDao().saveOrUpdateBySql(hql, null);}roadDataRepository.save(roadDataList);message.setType(Message.OK);message.setMsg("文件上传解析成功");}}} catch (Exception e) {e.printStackTrace();Message messageListener = easyExcelUtils.getMessage();if(null == messageListener || null == messageListener.getType()) {message.setType(Message.ERROR);message.setMsg("上传解析文件错误");}else {message = messageListener;}}return message.toJson();}

4.EasyExcelUtils类：使用@Component注解修饰，使类加载进spring容器中进行管理；数据的类型使用Object进行定义，定义一个Mesage类用于记录解析和验证表头是否与模板一致的信息；创建EasyExcelUtils时，传递一个接收解析excel类的class对象，使用注解ExcelProperty获取到类的字段，并与excel中的进行比对，验证导入的excel是否符合要求。

/*** @Description 使用easyexcel方式解析数据的工具类* @author qingyun* @Date 2021年5月19日 上午10:35:58*/
@Component
public class EasyExcelUtils extends AnalysisEventListener<Object> {List<Object> list = new ArrayList<Object>();Message message = new Message();Class clazz;public EasyExcelUtils() {super();// TODO Auto-generated constructor stub}public EasyExcelUtils(Class clazz) {super();this.clazz = clazz;}/*** @Description invoke方法为一行一行读取excel内容* @author qingyun* @Date 2021年5月19日 上午10:43:17*/@Overridepublic void invoke(Object data, AnalysisContext context) {list.add(data); }/*** @Description invokeHeadMap读取excel表头，校验表头是否正确* @author qingyun* @Date 2021年5月19日 上午10:44:43*/@Overridepublic void invokeHeadMap(Map<Integer, String> headMap, AnalysisContext context) {Map<Integer, String> head = new HashMap<>();try {head = getIndexNameMap(clazz);   //通过class获取到使用@ExcelProperty注解配置的字段} catch (NoSuchFieldException e) {e.printStackTrace();}Set<Integer> keySet = head.keySet();  //解析到的excel表头和实体配置的进行比对for (Integer key : keySet) {if (StringUtils.isEmpty(headMap.get(key))) {message.setType(Message.ERROR);message.setMsg("表头第"+key+1+"列为空，请参照模板填写");throw new ExcelAnalysisException("解析excel出错，请传入正确格式的excel");}if (!headMap.get(key).equals(head.get(key))) {message.setType(Message.ERROR);message.setMsg("表头第"+key+1+"列【"+headMap.get(key)+"】与模板【"+head.get(key)+"】不一致，请参照模板填写");throw new ExcelAnalysisException("解析excel出错，请传入正确格式的excel");}}}/*** @Description 读取完成之后进行的处理* @author qingyun* @Date 2021年5月19日 上午10:45:13*/@Overridepublic void doAfterAllAnalysed(AnalysisContext context) {if (null == message || message.getType() == null) {message.setMsg("数据解析完成");message.setType(Message.OK);}}/*** @Description 通过class获取类字段信息* @author qingyun* @Date 2021年5月19日 下午1:41:47*/public Map<Integer, String> getIndexNameMap(Class clazz) throws NoSuchFieldException {Map<Integer, String> result = new HashMap<>();Field field;Field[] fields = clazz.getDeclaredFields();     //获取类中所有的属性for (int i = 0; i < fields.length; i++) {field = clazz.getDeclaredField(fields[i].getName());field.setAccessible(true);ExcelProperty excelProperty = field.getAnnotation(ExcelProperty.class);//获取根据注解的方式获取ExcelProperty修饰的字段if (excelProperty != null) {int index = excelProperty.index();         //索引值String[] values = excelProperty.value();   //字段值StringBuilder value = new StringBuilder();for (String v : values) {value.append(v);}result.put(index, value.toString());}}return result;}/*** @Description 在转换异常 获取其他异常下会调用本接口。抛出异常则停止读取。如果这里不抛出异常则 继续读取下一行。* @author qingyun* @Date 2021年5月19日 下午3:02:49*/@Overridepublic void onException(Exception exception, AnalysisContext context) {// 如果是某一个单元格的转换异常 能获取到具体行号// 如果要获取头的信息 配合invokeHeadMap使用if (exception instanceof ExcelDataConvertException) {ExcelDataConvertException excelDataConvertException = (ExcelDataConvertException)exception;message.setType(Message.ERROR);message.setMsg("第"+(excelDataConvertException.getRowIndex()+1)+"行，第"+(excelDataConvertException.getColumnIndex()+1)+"列解析异常，请参照模板填写");}}public List<Object> getList() {return list;}public void setList(List<Object> list) {this.list = list;}public Message getMessage() {return message;}public void setMessage(Message message) {this.message = message;}}

5.RoadData实体类：使用@ExcelProperty注解标识字段，指定index和value，用于接收excel的值，以及进行表头的比对

public class RoadData implements Serializable {private static final long serialVersionUID = 1L;private String id;         //id@ExcelProperty(value = "年份",index = 0)private String repYear;         //年份@ExcelProperty(value = "养管单位",index = 1)private String unit;         //养管单位@ExcelProperty(value = "路线",index = 2)private String roadCode;         //路线编码@ExcelProperty(value = "上下行",index = 3)private String roadDirectName;         //行车方向@ExcelProperty(value = "路段起点",index = 4)private BigDecimal startStake;         //起点桩号@ExcelProperty(value = "路段终点",index = 5)private BigDecimal endStake;         //终点桩号@ExcelProperty(value = "长度km",index = 6)private BigDecimal roadLength;         //长度@ExcelProperty(value = "技术等级",index = 7)private String roadGradeName;         //技术等级@ExcelProperty(value = "路面类型",index = 8)private String paveTypeName;         //路面类型@ExcelProperty(value = "PQI",index = 9)private BigDecimal pqi;         //PQI@ExcelProperty(value = "PCI",index = 10)private BigDecimal pci;         //PCI@ExcelProperty(value = "RQI",index = 11)private BigDecimal rqi;         //rqi@ExcelProperty(value = "RDI",index = 12)private BigDecimal rdi;         //rdi@ExcelProperty(value = "DR",index = 13)private BigDecimal dr;         //dr@ExcelProperty(value = "IRI",index = 14)private BigDecimal iri;         //iri@ExcelProperty(value = "RD",index = 15)private BigDecimal rd;         //rdprivate BigDecimal pci_score;         //PCI得分private BigDecimal rqi_score;         //rqi得分private BigDecimal rdi_score;         //rdi得分@ExcelProperty(value = "PQI分级",index = 16)private String pqiGrade;         //PQI分级@ExcelProperty(value = "PCI分级",index = 17)private String pciGrade;         //PCI分级@ExcelProperty(value = "RQI分级",index = 18)private String rqiGrade;         //RQI分级@ExcelProperty(value = "RDI分级",index = 19)private String rdiGrade;         //RDI分级@ExcelProperty(value = "区域",index = 20)private String theAreaName;         //区域@ExcelProperty(value = "抽检性质",index = 21)private String randomNature;         //抽检性质@ExcelProperty(value = "PCI整改后得分",index = 22)private BigDecimal pciAfter;         //PCI整改后得分@ExcelProperty(value = "RQI整改后得分",index = 23)private BigDecimal rqiAfter;         //RQI整改后得分@ExcelProperty(value = "RDI整改后得分",index = 24)private BigDecimal rdiAfter;         //RDI整改后得分@ExcelProperty(value = "整改标识",index = 25)private String rectificaFlag;         //整改标识（未完成/已完成）private String createUserCode;private String createUserName;private Date createTime;
}

二.读取excel的相关技术点

1.读取excel的方式

（1）源码按路径path的方式

  public static ExcelReaderBuilder read(String pathName, Class head, ReadListener readListener) {ExcelReaderBuilder excelReaderBuilder = new ExcelReaderBuilder();excelReaderBuilder.file(pathName);if (head != null) {excelReaderBuilder.head(head);}if (readListener != null) {excelReaderBuilder.registerReadListener(readListener);}return excelReaderBuilder;}

（2）按文件输入流的方式读

  public static ExcelReaderBuilder read(InputStream inputStream, Class head, ReadListener readListener) {ExcelReaderBuilder excelReaderBuilder = new ExcelReaderBuilder();excelReaderBuilder.file(inputStream);if (head != null) {excelReaderBuilder.head(head);}if (readListener != null) {excelReaderBuilder.registerReadListener(readListener);}return excelReaderBuilder;}

（3）按file读取

 public static ExcelReaderBuilder read(File file, Class head, ReadListener readListener) {ExcelReaderBuilder excelReaderBuilder = new ExcelReaderBuilder();excelReaderBuilder.file(file);if (head != null) {excelReaderBuilder.head(head);}if (readListener != null) {excelReaderBuilder.registerReadListener(readListener);}return excelReaderBuilder;}

2.读取sheet数量

（1）只能读取到最前面的一个sheet

EasyExcel.read(fileInput,RoadData.class,easyExcelUtils).sheet().doRead()

（2）读取所有的sheet：

EasyExcel.read(fileInput,RoadData.class,easyExcelUtils).doReadAll()

（3）读取指定的sheet:

 ExcelReader excelReader = EasyExcel.read(fileInput).build();// 这里为了简单 所以注册了 同样的head 和Listener 自己使用功能必须不同的ListenerReadSheet readSheet1 =EasyExcel.readSheet(0).head(RoadData.class).registerReadListener(easyExcelUtils).build();ReadSheet readSheet2 =EasyExcel.readSheet(1).head(RoadData.class).registerReadListener(easyExcelUtils).build();// 这里注意 一定要把sheet1 sheet2 一起传进去，不然有个问题就是03版的excel 会读取多次，浪费性能excelReader.read(readSheet1, readSheet2);// 这里千万别忘记关闭，读的时候会创建临时文件，到时磁盘会崩的excelReader.finish();