easyExcel+validation+正则实现excel导入校验

背景：导入excel的时候，除了数据库校验数据以外，还会碰到数据格式校验，如果直接报错，显得客户体验很不好，我想到的做法是，导入正确的数据，错误的数据重新导出，并在后面加上错误信息。
环境准备：
spring:springboot2.X
easyExcel:2.1.4
lombok(非必须)
easyExcel官网：https://alibaba-easyexcel.github.io/index.html

1、pom文件引入easyExcel
com.alibaba easyexcel 2.1.4

  1. <dependency>
  2.     <groupId>org.apache.poi</groupId>
  3.     <artifactId>poi</artifactId>
  4.     <version>3.17</version>
  5. </dependency>
  6. <dependency>
  7.     <groupId>org.apache.poi</groupId>
  8.     <artifactId>poi-ooxml</artifactId>
  9.     <version>3.17</version>
  10. </dependency>
  11. <dependency>
  12.     <groupId>cglib</groupId>
  13.     <artifactId>cglib</artifactId>
  14.     <version>3.1</version>
  15. </dependency>
  16. <dependency>
  17.     <groupId>org.apache.poi</groupId>
  18.     <artifactId>ooxml-schemas</artifactId>
  19.     <version>1.1</version>
  20. </dependency>

2、通过easyExcel官方文档我们知道，easyExcel有一个监听器，用来读取excel数据，并且监听器不能被spring管理，要每次读取excel都要new,然后里面用到spring可以构造方法传进去
监听器实现如下：

  1. import com.alibaba.excel.annotation.ExcelProperty;
  2. import com.alibaba.excel.context.AnalysisContext;
  3. import com.alibaba.excel.event.AnalysisEventListener;
  4. import com.alibaba.excel.exception.ExcelAnalysisException;
  5. import lombok.Data;
  6. import org.apache.commons.lang3.StringUtils;
  7. import java.lang.reflect.Field;
  8. import java.util.*;
  10. /**
  11.  * @author zhy
  12.  * @title: EasyExcelListener
  13.  * @projectName cec-moutai-bd-display
  14.  * @description: easyExcel监听器
  15.  * @date 2019/12/2318:28
  16.  */
  17. @Data
  18. public class EasyExcelListener <T>  extends AnalysisEventListener<T> {
  20.     //成功结果集
  21.     private List<ExcelImportSucObjectDto> successList = new ArrayList<>();
  23.     //失败结果集
  24.     private List<ExcelImportErrObjectDto> errList = new ArrayList<>();
  26.     //处理逻辑service
  27.     private ExcelCheckManager excelCheckManager;
  29.     private List<T> list = new ArrayList<>();
  31.     //excel对象的反射类
  32.     private Class<T> clazz;
  34.     public EasyExcelListener(ExcelCheckManager excelCheckManager){
  35.         this.excelCheckManager = excelCheckManager;
  36.     }
  38.     public EasyExcelListener(ExcelCheckManager excelCheckManager,Class<T> clazz){
  39.         this.excelCheckManager = excelCheckManager;
  40.         this.clazz = clazz;
  41.     }
  43.     @Override
  44.     public void invoke(T t, AnalysisContext analysisContext) {
  45.         String errMsg;
  46.         try {
  47.             //根据excel数据实体中的javax.validation + 正则表达式来校验excel数据
  48.             errMsg = EasyExcelValiHelper.validateEntity(t);
  49.         } catch (NoSuchFieldException e) {
  50.             errMsg = "解析数据出错";
  51.             e.printStackTrace();
  52.         }
  53.         if (!StringUtils.isBlank(errMsg)){
  54.             ExcelImportErrObjectDto excelImportErrObjectDto = new ExcelImportErrObjectDto(t, errMsg);
  55.             errList.add(excelImportErrObjectDto);
  56.         }else{
  57.             list.add(t);
  58.         }
  59.         //每1000条处理一次
  60.         if (list.size() > 1000){
  61.             //校验
  62.             ExcelImportResult result = excelCheckManager.checkImportExcel(list);
  63.             successList.addAll(result.getSuccessDtos());
  64.             errList.addAll(result.getErrDtos());
  65.             list.clear();
  66.         }
  68.         // 达到BATCH_COUNT了，需要去存储一次数据库，防止数据几万条数据在内存，容易OOM
  69.         if (list.size() >= BATCH_COUNT) {
  70.             saveData();
  71.             // 存储完成清理 list
  72.             list.clear();
  73.         }
  74.     }
  76.     //所有数据解析完成了 都会来调用
  77.     @Override
  78.     public void doAfterAllAnalysed(AnalysisContext analysisContext) {
  79.         ExcelImportResult result = excelCheckManager.checkImportExcel(list);
  81.         successList.addAll(result.getSuccessDtos());
  82.         errList.addAll(result.getErrDtos());
  83.         list.clear();
  84.     }
  87.     /**
  88.       * @description: 校验excel头部格式，必须完全匹配
  89.       * @param headMap 传入excel的头部（第一行数据）数据的index,name
  90.       * @param context
  91.       * @throws
  92.       * @return void
  93.       * @author zhy
  94.       * @date 2019/12/24 19:27
  95.       */
  96.     @Override
  97.     public void invokeHeadMap(Map<Integer, String> headMap, AnalysisContext context) {
  98.         super.invokeHeadMap(headMap, context);
  99.         if (clazz != null){
  100.             try {
  101.                 Map<Integer, String> indexNameMap = getIndexNameMap(clazz);
  102.                 Set<Integer> keySet = indexNameMap.keySet();
  103.                 for (Integer key : keySet) {
  104.                     if (StringUtils.isBlank(headMap.get(key))){
  105.                         throw new ExcelAnalysisException("解析excel出错，请传入正确格式的excel");
  106.                     }
  107.                     if (!headMap.get(key).equals(indexNameMap.get(key))){
  108.                         throw new ExcelAnalysisException("解析excel出错，请传入正确格式的excel");
  109.                     }
  110.                 }
  112.             } catch (NoSuchFieldException e) {
  113.                 e.printStackTrace();
  114.             }
  115.         }
  116.     }
  118.     /**
  119.       * @description: 获取注解里ExcelProperty的value，用作校验excel
  120.       * @param clazz 
  121.       * @throws
  122.       * @return java.util.Map<java.lang.Integer,java.lang.String> 
  123.       * @author zhy
  124.       * @date 2019/12/24 19:21 
  125.       */
  126.     public Map<Integer,String> getIndexNameMap(Class clazz) throws NoSuchFieldException {
  127.         Map<Integer,String> result = new HashMap<>();
  128.         Field field;
  129.         Field[] fields=clazz.getDeclaredFields();
  130.         for (int i = 0; i <fields.length ; i++) {
  131.             field=clazz.getDeclaredField(fields[i].getName());
  132.             field.setAccessible(true);
  133.             ExcelProperty excelProperty=field.getAnnotation(ExcelProperty.class);
  134.             if(excelProperty!=null){
  135.                 int index = excelProperty.index();
  136.                 String[] values = excelProperty.value();
  137.                 StringBuilder value = new StringBuilder();
  138.                 for (String v : values) {
  139.                     value.append(v);
  140.                 }
  141.                 result.put(index,value.toString());
  142.             }
  143.         }
  144.         return result;
  145.     }
  146. }

3、成功结果集对象：ExcelImportSucObjectDto

  1. import lombok.Data;
  3. /**
  4.  * @author zhy
  5.  * @title: ExcelImportErrObjectDto
  6.  * @projectName cec-moutai-bd-display
  7.  * @description: excel单条数据导入结果
  8.  * @date 2019/12/2318:23
  9.  */
  10. @Data
  11. public class ExcelImportSucObjectDto {
  12.     private Object object;
  13. }

4、失败结果集对象：ExcelImportErrObjectDto

  1. import lombok.Data;
  3. /**
  4.  * @author zhy
  5.  * @title: ExcelImportErrObjectDto
  6.  * @projectName cec-moutai-bd-display
  7.  * @description: excel单条数据导入结果
  8.  * @date 2019/12/2318:23
  9.  */
  10. @Data
  11. public class ExcelImportErrObjectDto {
  12.     private Object object;
  13.     private String errMsg;
  14.     public ExcelImportErrObjectDto(){}
  15.     public ExcelImportErrObjectDto(Object object,String errMsg){
  16.         this.object = object;
  17.         this.errMsg = errMsg;
  18.     }
  19. }

5、业务校验接口：ExcelCheckManager。需要校验excel业务的service接口可以继承这个接口，并在实现类中实现自己的方法，返回的是成功失败的结果集 ExcelImportResult

  1. import java.util.List;
  3. /**
  4.  * @author zhy
  5.  * @title: ExcelCheckManager
  6.  * @projectName cec-moutai-bd-display
  7.  * @description: excel校验接口
  8.  * @date 2019/12/2317:44
  9.  */
  10. public interface ExcelCheckManager<T> {
  12.     /**
  13.       * @description: 校验方法
  14.       * @param objects 
  15.       * @throws
  16.       * @return com.cec.moutai.common.easyexcel.ExcelImportResult 
  17.       * @author zhy
  18.       * @date 2019/12/24 14:57 
  19.       */
  20.     <T> ExcelImportResult checkImportExcel(List<T> objects);
  21. }
  1. import lombok.Data;
  2. import java.util.ArrayList;
  3. import java.util.List;
  5. /**
  6.  * @author zhy
  7.  * @title: ExcelImportErrObjectDto
  8.  * @projectName cec-moutai-bd-display
  9.  * @description: excel数据导入结果
  10.  * @date 2019/12/2318:23
  11.  */
  12. @Data
  13. public class ExcelImportResult {
  14.     private List<ExcelImportSucObjectDto> successDtos;
  15.     private List<ExcelImportErrObjectDto> errDtos;
  16.     public ExcelImportResult(List<ExcelImportSucObjectDto> successDtos,List<ExcelImportErrObjectDto> errDtos){
  17.         this.successDtos =successDtos;
  18.         this.errDtos = errDtos;
  19.     }
  20.     public ExcelImportResult(List<ExcelImportErrObjectDto> errDtos){
  21.         this.successDtos =new ArrayList<>();
  22.         this.errDtos = errDtos;
  23.     }
  24. }

6、数据校验逻辑实现：通过正则校验excel数据的功能，后续也可以在此扩展加入其他校验接口。
@ExcelProperty是easyExcel自带的注解
@ColumnWidth也是easyExcel的注解代表单元格宽度
@Length代表的是字符串长度，max代表的是最长允许多长
@Pattern就是正则表达式注解了，regexp代表的是正则表达式，message代表是，没有匹配成功返回的错误信息
关于validation的注解可以参考此篇大佬的博客：https://blog.csdn.net/weixin_42546729/article/details/89364431

可以发现，我这里的接收对象都是String类型的，也正因为是这样，才能通过正则表达式去校验各种格式。
所以在excel类和真正的实体类之间的转换，我是用fastjson的JSON.parseObject来进行转换的。所以需要保证excel类和数据库实体的字段名要保持一致，数据格式，尤其是日期格式，要保持一致。

  1. import com.alibaba.excel.annotation.ExcelProperty;
  2. import com.alibaba.excel.annotation.write.style.ColumnWidth;
  3. import com.cec.moutai.common.easyexcel.ExcelPatternMsg;
  4. import lombok.Data;
  5. import org.hibernate.validator.constraints.Length;
  6. import javax.validation.constraints.DecimalMin;
  7. import javax.validation.constraints.Pattern;
  9. /**
  10.  * @author zhy
  11.  * @title: CustomerExcelDto
  12.  * @projectName cec-moutai-bd-display
  13.  * @description: 客户excel对象
  14.  * @date 2019/12/2410:35
  15.  */
  16. @Data
  17. public class CustomerExcelDto {
  20.     @ExcelProperty(index = 0,value = "客户全称")
  21.     @ColumnWidth(30)
  22.     private String name;
  24.     //客户简称
  25.     @ExcelProperty(index = 1,value = "客户简称")
  26.     @ColumnWidth(30)
  27.     @Length(max = 100)
  28.     private String shortName;
  30.     // 客户编码
  31.     @ExcelProperty(index = 2,value = "客户编码(导入必填)")
  32.     @ColumnWidth(30)
  33.     private String code;
  35.     @ExcelProperty(index = 3,value = "客户分类")
  36.     private String custclassName;
  38.     // 法人
  39.     @ExcelProperty(index = 6,value = "法定代表人")
  40.     @Length(max = 100)
  41.     private String legalbody;
  44.     // 营业期限
  45.     @ExcelProperty(index = 24,value = "营业期限(导入格式：yyyy-MM-dd)")
  46.     @Pattern(regexp = ExcelPatternMsg.DATE2,message = ExcelPatternMsg.DATE2_MSG)
  47.     private String businessEndDate;
  49. }

7、正则表达式实现类：ExcelPatternMsg

  1. import java.util.regex.Pattern;
  3. /**
  4.  * @author zhy
  5.  * @title: ExcelPatternMsg
  6.  * @projectName cec-moutai-bd-display
  7.  * @description: excel正则表达式，以及错误信息
  8.  * @date 2019/12/2614:22
  9.  */
  10. public class ExcelPatternMsg {
  12.     //只能输入整数或者小数
  13.     public static final String DECIMAL = "^[0-9]+\\.{0,1}[0-9]{0,2}$";
  14.     public static final String DECIMAL_MSG = "只能输入整数或者小数";
  16.     //日期格式 yyyy/MM/dd
  17.     public static final String DATE1 = "(([0-9]{3}[1-9]|[0-9]{2}[1-9][0-9]{1}|[0-9]{1}[1-9][0-9]{2}|[1-9][0-9]{3})\\/(((0[13578]|1[02])\\/(0[1-9]|[12][0-9]|3[01]))|"+
  18.             "((0[469]|11)\\/(0[1-9]|[12][0-9]|30))|(02\\/(0[1-9]|[1][0-9]|2[0-8]))))|((([0-9]{2})(0[48]|[2468][048]|[13579][26])|"+
  19.             "((0[48]|[2468][048]|[3579][26])00))\\/02\\/29)$";
  20.     public static final String DATE1_MSG = "输入正确的日期格式：yyyy/MM/dd";
  22.     //日期格式 yyyy-MM-dd
  23.     public static final String DATE2 = "(([0-9]{3}[1-9]|[0-9]{2}[1-9][0-9]{1}|[0-9]{1}[1-9][0-9]{2}|[1-9][0-9]{3})-(((0[13578]|1[02])-(0[1-9]|[12][0-9]|3[01]))|"+
  24.             "((0[469]|11)-(0[1-9]|[12][0-9]|30))|(02-(0[1-9]|[1][0-9]|2[0-8]))))|((([0-9]{2})(0[48]|[2468][048]|[13579][26])|"+
  25.             "((0[48]|[2468][048]|[3579][26])00))-02-29)$";
  26.     public static final String DATE2_MSG = "输入正确的日期格式：yyyy-MM-dd";
  28.     //日期格式 yyyyMMdd
  29.     public static final String DATE3 = "(([0-9]{3}[1-9]|[0-9]{2}[1-9][0-9]{1}|[0-9]{1}[1-9][0-9]{2}|[1-9][0-9]{3})(((0[13578]|1[02])(0[1-9]|[12][0-9]|3[01]))|"+
  30.             "((0[469]|11)(0[1-9]|[12][0-9]|30))|(02(0[1-9]|[1][0-9]|2[0-8]))))|((([0-9]{2})(0[48]|[2468][048]|[13579][26])|"+
  31.             "((0[48]|[2468][048]|[3579][26])00))0229)$";
  32.     public static final String DATE3_MSG = "输入正确的日期格式：yyyyMMdd";
  34.     //日期格式 yyyy-MM-dd HH:mm:ss
  35.     public static final String DATE_TIME1 = "^((([0-9]{3}[1-9]|[0-9]{2}[1-9][0-9]{1}|[0-9]{1}[1-9][0-9]{2}|[1-9][0-9]{3})-(((0[13578]|1[02])-(0[1-9]|[12][0-9]|3[01]))|" +
  36.             "((0[469]|11)-(0[1-9]|[12][0-9]|30))|(02-(0[1-9]|[1][0-9]|2[0-8]))))|((([0-9]{2})(0[48]|[2468][048]|[13579][26])|((0[48]|[2468][048]|[3579][26])00))-02-29))\\s+([0-1]?[0-9]|2[0-3]):([0-5][0-9]):([0-5][0-9])$";
  37.     public static final String DATE_TIME1_MSG = "输入正确的日期格式：yyyy-MM-dd HH:mm:ss";
  39.     //日期格式 yyyy/MM/dd HH:mm:ss
  40.     public static final String DATE_TIME2 = "((([0-9]{3}[1-9]|[0-9]{2}[1-9][0-9]{1}|[0-9]{1}[1-9][0-9]{2}|[1-9][0-9]{3})\\/(((0[13578]|1[02])\\/(0[1-9]|[12][0-9]|3[01]))|"+
  41.             "((0[469]|11)\\/(0[1-9]|[12][0-9]|30))|(02\\/(0[1-9]|[1][0-9]|2[0-8]))))|((([0-9]{2})(0[48]|[2468][048]|[13579][26])|"+
  42.             "((0[48]|[2468][048]|[3579][26])00))\\/02\\/29))\\s([0-1][0-9]|2[0-3]):([0-5][0-9]):([0-5][0-9])$";
  43.     public static final String DATE_TIME2_MSG = "输入正确的日期格式：yyyy/MM/dd HH:mm:ss";
  45.     //日期格式 yyyyMMddHHmmss
  46.     public static final String DATE_TIME3 = "((([0-9]{3}[1-9]|[0-9]{2}[1-9][0-9]{1}|[0-9]{1}[1-9][0-9]{2}|[1-9][0-9]{3})(((0[13578]|1[02])(0[1-9]|[12][0-9]|3[01]))|"+
  47.             "((0[469]|11)(0[1-9]|[12][0-9]|30))|(02(0[1-9]|[1][0-9]|2[0-8]))))|((([0-9]{2})(0[48]|[2468][048]|[13579][26])|((0[48]|[2468][048]|[3579][26])00))0229))"+
  48.             "([0-1][0-9]|2[0-3])([0-5][0-9])([0-5][0-9])$";
  49.     public static final String DATE_TIME3_MSG = "输入正确的日期格式：yyyyMMddHHmmss";
  51.     //日期格式 yyyyMMddHHmmssSSS
  52.     public static final String DATE_TIME4 = "((([0-9]{3}[1-9]|[0-9]{2}[1-9][0-9]{1}|[0-9]{1}[1-9][0-9]{2}|[1-9][0-9]{3})(((0[13578]|1[02])(0[1-9]|[12][0-9]|3[01]))|"+
  53.             "((0[469]|11)(0[1-9]|[12][0-9]|30))|(02(0[1-9]|[1][0-9]|2[0-8]))))|((([0-9]{2})(0[48]|[2468][048]|[13579][26])|"+
  54.             "((0[48]|[2468][048]|[3579][26])00))0229))([0-1][0-9]|2[0-3])([0-5][0-9])([0-5][0-9])([0-9]{3})$";
  55.     public static final String DATE_TIME4_MSG = "输入正确的日期格式：yyyyMMddHHmmssSSS";
  57.     //日期格式 yyyyMMdd HH:mm:ss
  58.     public static final String DATE_TIME5 = "((([0-9]{3}[1-9]|[0-9]{2}[1-9][0-9]{1}|[0-9]{1}[1-9][0-9]{2}|[1-9][0-9]{3})(((0[13578]|1[02])(0[1-9]|[12][0-9]|3[01]))|"+
  59.             "((0[469]|11)(0[1-9]|[12][0-9]|30))|(02(0[1-9]|[1][0-9]|2[0-8]))))|((([0-9]{2})(0[48]|[2468][048]|[13579][26])|"+
  60.             "((0[48]|[2468][048]|[3579][26])00))0229))\\s([0-1][0-9]|2[0-3]):([0-5][0-9]):([0-5][0-9])$";
  61.     public static final String DATE_TIME5_MSG = "输入正确的日期格式：yyyyMMdd HH:mm:ss";
  63.     //数字和字母
  64.     public static final String NUMBER_LETTER = "^[a-z0-9A-Z]+$";
  65.     public static final String NUMBER_LETTER_MSG = "只能输入数字和字母";
  67.     //数字
  68.     public static final String NUMBER = "^[0-9]*$";
  69.     public static final String NUMBER_MSG = "只能输入数字";
  71.     public static void main(String[] args) {
  72.         System.out.println(Pattern.matches(DATE1,"2020/02/30"));
  73.     }
  74. }

EasyExcelValiHelper.validateEntity(t)的写法

  1. import com.alibaba.excel.annotation.ExcelProperty;
  3. import javax.validation.ConstraintViolation;
  4. import javax.validation.Validation;
  5. import javax.validation.Validator;
  6. import javax.validation.groups.Default;
  7. import java.lang.reflect.Field;
  8. import java.util.ArrayList;
  9. import java.util.List;
  10. import java.util.Set;
  13. public class EasyExcelValiHelper {
  15.     private static Validator validator = Validation.buildDefaultValidatorFactory().getValidator();
  17.     public static <T> String validateEntity(T obj) throws NoSuchFieldException, SecurityException {
  18.         StringBuilder result = new StringBuilder();
  19.         Set<ConstraintViolation<T>> set = validator.validate(obj, Default.class);
  20.         if (set != null && set.size() != 0) {
  21.             for (ConstraintViolation<T> cv : set) {
  22.                 Field declaredField = obj.getClass().getDeclaredField(cv.getPropertyPath().toString());
  23.                 ExcelProperty annotation = declaredField.getAnnotation(ExcelProperty.class);
  24.                 result.append(annotation.value()[0]+cv.getMessage()).append(";");
  25.             }
  26.         }
  27.         return result.toString();
  28.     }
  30. }

8、控制层入口写法：

  1. @PostMapping(value = "importExcel")
  2. @ApiOperation(value = "客户信息导入")
  3. @SysServiceLog(operateContent = "客户信息导入", operateType = Globals.Log_Type_UPLOAD)
  4. public Result importExcel(HttpServletResponse response,@RequestParam MultipartFile file) throws IOException {
  5.     EasyExcelListener easyExcelListener = new EasyExcelListener(customerManager,CustomerExcelDto.class);
  6.     EasyExcel.read(file.getInputStream(),CustomerExcelDto.class,easyExcelListener).sheet().doRead();
  7.     //错误结果集
  8.     List<ExcelImportErrObjectDto> errList = easyExcelListener.getErrList();
  9.     if (errList.size() > 0){
  10.         List<CustomerCompleteDtoImprotResult> completeDtoImprotResults = errList.stream().map(excelImportErrObjectDto -> {
  11.             CustomerCompleteDtoImprotResult customerCompleteDtoImprotResult = BeanUtils.convert(excelImportErrObjectDto.getObject(), CustomerCompleteDtoImprotResult.class);
  12.             customerCompleteDtoImprotResult.setErrMsg(excelImportErrObjectDto.getErrMsg());
  13.             return customerCompleteDtoImprotResult;
  14.         }).collect(Collectors.toList());
  15.         //导出excel
  16.         EasyExcelUtils.webWriteExcel(response,completeDtoImprotResults,CustomerCompleteDtoImprotResult.class,"客户信息");
  17.     }
  18.     return addSucResult();
  19. }

9、导出工具封装：EasyExcelUtils

  1. import com.alibaba.excel.EasyExcel;
  2. import com.alibaba.excel.write.metadata.style.WriteCellStyle;
  3. import com.alibaba.excel.write.style.HorizontalCellStyleStrategy;
  4. import org.apache.poi.ss.formula.functions.T;
  5. import org.apache.poi.ss.usermodel.IndexedColors;
  6. import javax.servlet.ServletOutputStream;
  7. import javax.servlet.http.HttpServletResponse;
  8. import java.io.IOException;
  9. import java.util.List;
  11. /**
  12.  * @author zhy
  13.  * @title: EasyExcelUtils
  14.  * @projectName cec-moutai-bd-display
  15.  * @description: easyExcel工具类
  16.  * @date 2019/12/2411:35
  17.  */
  18. public class EasyExcelUtils {
  20.     public static void webWriteExcel(HttpServletResponse response, List objects, Class clazz, String fileName) throws IOException {
  21.         String sheetName = fileName;
  22.         webWriteExcel(response,objects,clazz,fileName,sheetName);
  23.     }
  24.     public static void webWriteExcel(HttpServletResponse response, List objects, Class clazz, String fileName, String sheetName) throws IOException {
  25.         response.setContentType("application/vnd.ms-excel");
  26.         response.setCharacterEncoding("utf-8");
  27.         response.setHeader("Content-disposition", "attachment;filename=" + fileName + ".xlsx");
  28.         // 头的策略
  29.         WriteCellStyle headWriteCellStyle = new WriteCellStyle();
  30.         // 背景设置为白
  31.         headWriteCellStyle.setFillForegroundColor(IndexedColors.WHITE.getIndex());
  32.         // 内容的策略
  33.         WriteCellStyle contentWriteCellStyle = new WriteCellStyle();
  34.         HorizontalCellStyleStrategy horizontalCellStyleStrategy =
  35.                 new HorizontalCellStyleStrategy(headWriteCellStyle, contentWriteCellStyle);
  36.         ServletOutputStream outputStream = response.getOutputStream();
  37.         try {
  38.             EasyExcel.write(outputStream, clazz).registerWriteHandler(horizontalCellStyleStrategy).sheet(sheetName).doWrite(objects);
  39.         }catch (Exception e){
  40.             e.printStackTrace();
  41.         }finally {
  42.             outputStream.close();
  43.         }
  44.     }
  45. }