content: package com.ruoyi.common.utils.poi;
  
  import java.io.File;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.lang.reflect.Field;
  import java.lang.reflect.Method;
  import java.text.DecimalFormat;
  import java.util.ArrayList;
  import java.util.Date;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.UUID;
  import org.apache.poi.hssf.usermodel.DVConstraint;
  import org.apache.poi.hssf.usermodel.HSSFDataValidation;
  import org.apache.poi.hssf.usermodel.HSSFDateUtil;
  import org.apache.poi.hssf.usermodel.HSSFFont;
  import org.apache.poi.hssf.util.HSSFColor.HSSFColorPredefined;
  import org.apache.poi.ss.usermodel.Cell;
  import org.apache.poi.ss.usermodel.CellStyle;
  import org.apache.poi.ss.usermodel.CellType;
  import org.apache.poi.ss.usermodel.DateUtil;
  import org.apache.poi.ss.usermodel.FillPatternType;
  import org.apache.poi.ss.usermodel.Font;
  import org.apache.poi.ss.usermodel.HorizontalAlignment;
  import org.apache.poi.ss.usermodel.Row;
  import org.apache.poi.ss.usermodel.Sheet;
  import org.apache.poi.ss.usermodel.VerticalAlignment;
  import org.apache.poi.ss.usermodel.Workbook;
  import org.apache.poi.ss.usermodel.WorkbookFactory;
  import org.apache.poi.ss.util.CellRangeAddressList;
  import org.apache.poi.xssf.streaming.SXSSFWorkbook;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import com.ruoyi.common.annotation.Excel;
  import com.ruoyi.common.annotation.Excel.Type;
  import com.ruoyi.common.base.AjaxResult;
  import com.ruoyi.common.config.Global;
  import com.ruoyi.common.exception.BusinessException;
  import com.ruoyi.common.reflect.ReflectUtils;
  import com.ruoyi.common.support.Convert;
  import com.ruoyi.common.utils.DateUtils;
  import com.ruoyi.common.utils.StringUtils;
  
  /**
   * Excel相关处理
   * 
   * @author ruoyi
   */
  public class ExcelUtil<T>
  {
      private static final Logger log = LoggerFactory.getLogger(ExcelUtil.class);
  
      /**
       * Excel sheet最大行数，默认65536
       */
      public static final int sheetSize = 65536;
  
      /**
       * 工作表名称
       */
      private String sheetName;
  
      /**
       * 导出类型（EXPORT:导出数据；IMPORT：导入模板）
       */
      private Type type;
  
      /**
       * 工作薄对象
       */
      private Workbook wb;
  
      /**
       * 工作表对象
       */
      private Sheet sheet;
  
      /**
       * 导入导出数据列表
       */
      private List<T> list;
  
      /**
       * 注解列表
       */
      private List<Field> fields;
  
      /**
       * 实体对象
       */
      public Class<T> clazz;
  
      public ExcelUtil(Class<T> clazz)
      {
          this.clazz = clazz;
      }
  
      public void init(List<T> list, String sheetName, Type type)
      {
          if (list == null)
          {
              list = new ArrayList<T>();
          }
          this.list = list;
          this.sheetName = sheetName;
          this.type = type;
          createExcelField();
          createWorkbook();
      }
  
      /**
       * 对excel表单默认第一个索引名转换成list
       * 
       * @param input 输入流
       * @return 转换后集合
       */
      public List<T> importExcel(InputStream is) throws Exception
      {
          return importExcel(StringUtils.EMPTY, is);
      }
  
      /**
       * 对excel表单指定表格索引名转换成list
       * 
       * @param sheetName 表格索引名
       * @param input 输入流
       * @return 转换后集合
       */
      public List<T> importExcel(String sheetName, InputStream is) throws Exception
      {
          this.type = Type.IMPORT;
          this.wb = WorkbookFactory.create(is);
          List<T> list = new ArrayList<T>();
          Sheet sheet = null;
          if (StringUtils.isNotEmpty(sheetName))
          {
              // 如果指定sheet名,则取指定sheet中的内容.
              sheet = wb.getSheet(sheetName);
          }
          else
          {
              // 如果传入的sheet名不存在则默认指向第1个sheet.
              sheet = wb.getSheetAt(0);
          }
  
          if (sheet == null)
          {
              throw new IOException("文件sheet不存在");
          }
  
          int rows = sheet.getPhysicalNumberOfRows();
  
          if (rows > 0)
          {
              // 默认序号
              int serialNum = 0;
              // 有数据时才处理 得到类的所有field.
              Field[] allFields = clazz.getDeclaredFields();
              // 定义一个map用于存放列的序号和field.
              Map<Integer, Field> fieldsMap = new HashMap<Integer, Field>();
              for (int col = 0; col < allFields.length; col++)
              {
                  Field field = allFields[col];
                  Excel attr = field.getAnnotation(Excel.class);
                  if (attr != null && (attr.type() == Type.ALL || attr.type() == type))
                  {
                      // 设置类的私有字段属性可访问.
                      field.setAccessible(true);
                      fieldsMap.put(++serialNum, field);
                  }
              }
              for (int i = 1; i < rows; i++)
              {
                  // 从第2行开始取数据,默认第一行是表头.
                  Row row = sheet.getRow(i);
                  int cellNum = serialNum;
                  T entity = null;
                  for (int column = 0; column < cellNum; column++)
                  {
                      Object val = this.getCellValue(row, column);
  
                      // 如果不存在实例则新建.
                      entity = (entity == null ? clazz.newInstance() : entity);
                      // 从map中得到对应列的field.
                      Field field = fieldsMap.get(column + 1);
                      // 取得类型,并根据对象类型设置值.
                      Class<?> fieldType = field.getType();
                      if (String.class == fieldType)
                      {
                          String s = Convert.toStr(val);
                          if (StringUtils.endsWith(s, ".0"))
                          {
                              val = StringUtils.substringBefore(s, ".0");
                          }
                          else
                          {
                              val = Convert.toStr(val);
                          }
                      }
                      else if ((Integer.TYPE == fieldType) || (Integer.class == fieldType))
                      {
                          val = Convert.toInt(val);
                      }
                      else if ((Long.TYPE == fieldType) || (Long.class == fieldType))
                      {
                          val = Convert.toLong(val);
                      }
                      else if ((Double.TYPE == fieldType) || (Double.class == fieldType))
                      {
                          val = Convert.toDouble(val);
                      }
                      else if ((Float.TYPE == fieldType) || (Float.class == fieldType))
                      {
                          val = Convert.toFloat(val);
                      }
                      else if (Date.class == fieldType)
                      {
                          if (val instanceof String)
                          {
                              val = DateUtils.parseDate(val);
                          }
                          else if (val instanceof Double)
                          {
                              val = DateUtil.getJavaDate((Double) val);
                          }
                      }
                      if (StringUtils.isNotNull(fieldType))
                      {
                          Excel attr = field.getAnnotation(Excel.class);
                          String propertyName = field.getName();
                          if (StringUtils.isNotEmpty(attr.targetAttr()))
                          {
                              propertyName = field.getName() + "." + attr.targetAttr();
                          }
                          else if (StringUtils.isNotEmpty(attr.readConverterExp()))
                          {
                              val = reverseByExp(String.valueOf(val), attr.readConverterExp());
                          }
                          ReflectUtils.invokeSetter(entity, propertyName, val);
                      }
                  }
                  list.add(entity);
              }
          }
          return list;
      }
  
      /**
       * 对list数据源将其里面的数据导入到excel表单
       * 
       * @param list 导出数据集合
       * @param sheetName 工作表的名称
       * @return 结果
       */
      public AjaxResult exportExcel(List<T> list, String sheetName)
      {
          this.init(list, sheetName, Type.EXPORT);
          return exportExcel();
      }
  
      /**
       * 对list数据源将其里面的数据导入到excel表单
       * 
       * @param sheetName 工作表的名称
       * @return 结果
       */
      public AjaxResult importTemplateExcel(String sheetName)
      {
          this.init(null, sheetName, Type.IMPORT);
          return exportExcel();
      }
  
      /**
       * 对list数据源将其里面的数据导入到excel表单
       * 
       * @return 结果
       */
      public AjaxResult exportExcel()
      {
          OutputStream out = null;
          try
          {
              // 取出一共有多少个sheet.
              double sheetNo = Math.ceil(list.size() / sheetSize);
              for (int index = 0; index <= sheetNo; index++)
              {
                  createSheet(sheetNo, index);
                  Cell cell = null; // 产生单元格
  
                  // 产生一行
                  Row row = sheet.createRow(0);
                  // 写入各个字段的列头名称
                  for (int i = 0; i < fields.size(); i++)
                  {
                      Field field = fields.get(i);
                      Excel attr = field.getAnnotation(Excel.class);
                      // 创建列
                      cell = row.createCell(i);
                      // 设置列中写入内容为String类型
                      cell.setCellType(CellType.STRING);
                      CellStyle cellStyle = wb.createCellStyle();
                      cellStyle.setAlignment(HorizontalAlignment.CENTER);
                      cellStyle.setVerticalAlignment(VerticalAlignment.CENTER);
                      if (attr.name().indexOf("注：") >= 0)
                      {
                          Font font = wb.createFont();
                          font.setColor(HSSFFont.COLOR_RED);
                          cellStyle.setFont(font);
                          cellStyle.setFillForegroundColor(HSSFColorPredefined.YELLOW.getIndex());
                          sheet.setColumnWidth(i, 6000);
                      }
                      else
                      {
                          Font font = wb.createFont();
                          // 粗体显示
                          font.setBold(true);
                          // 选择需要用到的字体格式
                          cellStyle.setFont(font);
                          cellStyle.setFillForegroundColor(HSSFColorPredefined.LIGHT_YELLOW.getIndex());
                          // 设置列宽
                          sheet.setColumnWidth(i, (int) ((attr.width() + 0.72) * 256));
                          row.setHeight((short) (attr.height() * 20));
                      }
                      cellStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);
                      cellStyle.setWrapText(true);
                      cell.setCellStyle(cellStyle);
  
                      // 写入列名
                      cell.setCellValue(attr.name());
  
                      // 如果设置了提示信息则鼠标放上去提示.
                      if (StringUtils.isNotEmpty(attr.prompt()))
                      {
                          // 这里默认设了2-101列提示.
                          setHSSFPrompt(sheet, "", attr.prompt(), 1, 100, i, i);
                      }
                      // 如果设置了combo属性则本列只能选择不能输入
                      if (attr.combo().length > 0)
                      {
                          // 这里默认设了2-101列只能选择不能输入.
                          setHSSFValidation(sheet, attr.combo(), 1, 100, i, i);
                      }
                  }
                  if (Type.EXPORT.equals(type))
                  {
                      fillExcelData(index, row, cell);
                  }
              }
              String filename = encodingFilename(sheetName);
              out = new FileOutputStream(getAbsoluteFile(filename));
              wb.write(out);
              return AjaxResult.success(filename);
          }
          catch (Exception e)
          {
              log.error("导出Excel异常{}", e.getMessage());
              throw new BusinessException("导出Excel失败，请联系网站管理员！");
          }
          finally
          {
              if (wb != null)
              {
                  try
                  {
                      wb.close();
                  }
                  catch (IOException e1)
                  {
                      e1.printStackTrace();
                  }
              }
              if (out != null)
              {
                  try
                  {
                      out.close();
                  }
                  catch (IOException e1)
                  {
                      e1.printStackTrace();
                  }
              }
          }
      }
  
      /**
       * 填充excel数据
       * 
       * @param index 序号
       * @param row 单元格行
       * @param cell 类型单元格
       */
      public void fillExcelData(int index, Row row, Cell cell)
      {
          int startNo = index * sheetSize;
          int endNo = Math.min(startNo + sheetSize, list.size());
          // 写入各条记录,每条记录对应excel表中的一行
          CellStyle cs = wb.createCellStyle();
          cs.setAlignment(HorizontalAlignment.CENTER);
          cs.setVerticalAlignment(VerticalAlignment.CENTER);
          for (int i = startNo; i < endNo; i++)
          {
              row = sheet.createRow(i + 1 - startNo);
              // 得到导出对象.
              T vo = (T) list.get(i);
              for (int j = 0; j < fields.size(); j++)
              {
                  // 获得field.
                  Field field = fields.get(j);
                  // 设置实体类私有属性可访问
                  field.setAccessible(true);
                  Excel attr = field.getAnnotation(Excel.class);
                  try
                  {
                      // 设置行高
                      row.setHeight((short) (attr.height() * 20));
                      // 根据Excel中设置情况决定是否导出,有些情况需要保持为空,希望用户填写这一列.
                      if (attr.isExport())
                      {
                          // 创建cell
                          cell = row.createCell(j);
                          cell.setCellStyle(cs);
                          if (vo == null)
                          {
                              // 如果数据存在就填入,不存在填入空格.
                              cell.setCellValue("");
                              continue;
                          }
  
                          // 用于读取对象中的属性
                          Object value = getTargetValue(vo, field, attr);
                          String dateFormat = attr.dateFormat();
                          String readConverterExp = attr.readConverterExp();
                          if (StringUtils.isNotEmpty(dateFormat))
                          {
                              cell.setCellValue(DateUtils.parseDateToStr(dateFormat, (Date) value));
                          }
                          else if (StringUtils.isNotEmpty(readConverterExp))
                          {
                              cell.setCellValue(convertByExp(String.valueOf(value), readConverterExp));
                          }
                          else
                          {
                              cell.setCellType(CellType.STRING);
                              // 如果数据存在就填入,不存在填入空格.
                              cell.setCellValue(StringUtils.isNull(value) ? attr.defaultValue() : value + attr.suffix());
                          }
                      }
                  }
                  catch (Exception e)
                  {
                      log.error("导出Excel失败{}", e.getMessage());
                  }
              }
          }
      }
  
      /**
       * 设置单元格上提示
       * 
       * @param sheet 要设置的sheet.
       * @param promptTitle 标题
       * @param promptContent 内容
       * @param firstRow 开始行
       * @param endRow 结束行
       * @param firstCol 开始列
       * @param endCol 结束列
       * @return 设置好的sheet.
       */
      public static Sheet setHSSFPrompt(Sheet sheet, String promptTitle, String promptContent, int firstRow, int endRow,
              int firstCol, int endCol)
      {
          // 构造constraint对象
          DVConstraint constraint = DVConstraint.createCustomFormulaConstraint("DD1");
          // 四个参数分别是：起始行、终止行、起始列、终止列
          CellRangeAddressList regions = new CellRangeAddressList(firstRow, endRow, firstCol, endCol);
          // 数据有效性对象
          HSSFDataValidation dataValidationView = new HSSFDataValidation(regions, constraint);
          dataValidationView.createPromptBox(promptTitle, promptContent);
          sheet.addValidationData(dataValidationView);
          return sheet;
      }
  
      /**
       * 设置某些列的值只能输入预制的数据,显示下拉框.
       * 
       * @param sheet 要设置的sheet.
       * @param textlist 下拉框显示的内容
       * @param firstRow 开始行
       * @param endRow 结束行
       * @param firstCol 开始列
       * @param endCol 结束列
       * @return 设置好的sheet.
       */
      public static Sheet setHSSFValidation(Sheet sheet, String[] textlist, int firstRow, int endRow, int firstCol,
              int endCol)
      {
          // 加载下拉列表内容
          DVConstraint constraint = DVConstraint.createExplicitListConstraint(textlist);
          // 设置数据有效性加载在哪个单元格上,四个参数分别是：起始行、终止行、起始列、终止列
          CellRangeAddressList regions = new CellRangeAddressList(firstRow, endRow, firstCol, endCol);
          // 数据有效性对象
          HSSFDataValidation dataValidationList = new HSSFDataValidation(regions, constraint);
          sheet.addValidationData(dataValidationList);
          return sheet;
      }
  
      /**
       * 解析导出值 0=男,1=女,2=未知
       * 
       * @param propertyValue 参数值
       * @param converterExp 翻译注解
       * @return 解析后值
       * @throws Exception
       */
      public static String convertByExp(String propertyValue, String converterExp) throws Exception
      {
          try
          {
              String[] convertSource = converterExp.split(",");
              for (String item : convertSource)
              {
                  String[] itemArray = item.split("=");
                  if (itemArray[0].equals(propertyValue))
                  {
                      return itemArray[1];
                  }
              }
          }
          catch (Exception e)
          {
              throw e;
          }
          return propertyValue;
      }
  
      /**
       * 反向解析值 男=0,女=1,未知=2
       * 
       * @param propertyValue 参数值
       * @param converterExp 翻译注解
       * @return 解析后值
       * @throws Exception
       */
      public static String reverseByExp(String propertyValue, String converterExp) throws Exception
      {
          try
          {
              String[] convertSource = converterExp.split(",");
              for (String item : convertSource)
              {
                  String[] itemArray = item.split("=");
                  if (itemArray[1].equals(propertyValue))
                  {
                      return itemArray[0];
                  }
              }
          }
          catch (Exception e)
          {
              throw e;
          }
          return propertyValue;
      }
  
      /**
       * 编码文件名
       */
      public String encodingFilename(String filename)
      {
          filename = UUID.randomUUID().toString() + "_" + filename + ".xlsx";
          return filename;
      }
  
      /**
       * 获取下载路径
       * 
       * @param filename 文件名称
       */
      public String getAbsoluteFile(String filename)
      {
          String downloadPath = Global.getDownloadPath() + filename;
          File desc = new File(downloadPath);
          if (!desc.getParentFile().exists())
          {
              desc.getParentFile().mkdirs();
          }
          return downloadPath;
      }
  
      /**
       * 获取bean中的属性值
       * 
       * @param vo 实体对象
       * @param field 字段
       * @param excel 注解
       * @return 最终的属性值
       * @throws Exception
       */
      private Object getTargetValue(T vo, Field field, Excel excel) throws Exception
      {
          Object o = field.get(vo);
          if (StringUtils.isNotEmpty(excel.targetAttr()))
          {
              String target = excel.targetAttr();
              if (target.indexOf(".") > -1)
              {
                  String[] targets = target.split("[.]");
                  for (String name : targets)
                  {
                      o = getValue(o, name);
                  }
              }
              else
              {
                  o = getValue(o, target);
              }
          }
          return o;
      }
  
      /**
       * 以类的属性的get方法方法形式获取值
       * 
       * @param o
       * @param name
       * @return value
       * @throws Exception
       */
      private Object getValue(Object o, String name) throws Exception
      {
          if (StringUtils.isNotEmpty(name))
          {
              Class<?> clazz = o.getClass();
              String methodName = "get" + name.substring(0, 1).toUpperCase() + name.substring(1);
              Method method = clazz.getMethod(methodName);
              o = method.invoke(o);
          }
          return o;
      }
  
      /**
       * 得到所有定义字段
       */
      private void createExcelField()
      {
          this.fields = new ArrayList<Field>();
          Field[] allFields = clazz.getDeclaredFields();
          // 得到所有field并存放到一个list中.
          for (Field field : allFields)
          {
              Excel attr = field.getAnnotation(Excel.class);
              if (attr != null && (attr.type() == Type.ALL || attr.type() == type))
              {
                  fields.add(field);
              }
          }
      }
  
      /**
       * 创建一个工作簿
       */
      public void createWorkbook()
      {
          this.wb = new SXSSFWorkbook(500);
      }
  
      /**
       * 创建工作表
       * 
       * @param sheetName，指定Sheet名称
       * @param sheetNo sheet数量
       * @param index 序号
       */
      public void createSheet(double sheetNo, int index)
      {
          this.sheet = wb.createSheet();
          // 设置工作表的名称.
          if (sheetNo == 0)
          {
              wb.setSheetName(index, sheetName);
          }
          else
          {
              wb.setSheetName(index, sheetName + index);
          }
      }
  
      /**
       * 获取单元格值
       * 
       * @param row 获取的行
       * @param column 获取单元格列号
       * @return 单元格值
       */
      public Object getCellValue(Row row, int column)
      {
          if (row == null)
          {
              return row;
          }
          Object val = "";
          try
          {
              Cell cell = row.getCell(column);
              if (cell != null)
              {
                  if (cell.getCellTypeEnum() == CellType.NUMERIC)
                  {
                      val = cell.getNumericCellValue();
                      if (HSSFDateUtil.isCellDateFormatted(cell))
                      {
                          val = DateUtil.getJavaDate((Double) val); // POI Excel 日期格式转换
                      }
                      else
                      {
                          if ((Double) val % 1 > 0)
                          {
                              val = new DecimalFormat("0.00").format(val);
                          }
                          else
                          {
                              val = new DecimalFormat("0").format(val);
                          }
                      }
                  }
                  else if (cell.getCellTypeEnum() == CellType.STRING)
                  {
                      val = cell.getStringCellValue();
                  }
                  else if (cell.getCellTypeEnum() == CellType.BOOLEAN)
                  {
                      val = cell.getBooleanCellValue();
                  }
                  else if (cell.getCellTypeEnum() == CellType.ERROR)
                  {
                      val = cell.getErrorCellValue();
                  }
  
              }
          }
          catch (Exception e)
          {
              return val;
          }
          return val;
      }
  }