Apache POI - 读取由 TEXT() 公式格式化的单元格

Question

我有一个包含日期的 EXCEL 文件。它们被格式化为 TEXT，例如：=TEXT(TODAY(); "yyyy-MM-dd")

在 EXCEL 中，日期被正确格式化为文本，但是当我使用 Apache POI 读取单元格时，它将返回数值。 为什么？为什么 POI 不读取格式化文本值？

我不想在我的 JAVA 应用程序中格式化日期，因为 EXCEL 文件应该定义格式（每个值可能不同）。

这是我读取单元格值的代码：

private static String getString(Cell cell) {
 if (cell == null) return null; 

 if (cell.getCellTypeEnum() != CellType.FORMULA) { 
  switch (cell.getCellTypeEnum()) { 
   case STRING: 
    return cell.getStringCellValue().trim(); 
   case BOOLEAN: 
    return String.valueOf(cell.getBooleanCellValue());
   case NUMERIC: 
    return String.valueOf(cell.getNumericCellValue()); 
   case BLANK: 
    return null; 
   case ERROR: 
    throw new RuntimeException(ErrorEval.getText(cell.getErrorCellValue())); 
   default: 
    throw new RuntimeException("unexpected cell type " + cell.getCellTypeEnum());
  }
 } 
 FormulaEvaluator evaluator = cell.getSheet().getWorkbook().getCreationHelper().createFormulaEvaluator();
 try { 
  CellValue cellValue = evaluator.evaluate(cell); 
  switch (cellValue.getCellTypeEnum()) { 
   case NUMERIC: 
    return String.valueOf(cellValue.getNumberValue());
   case STRING: 
    return cellValue.getStringValue().trim(); 
   case BOOLEAN: 
    return String.valueOf(cellValue.getBooleanValue()); 
   case ERROR: 
    throw new RuntimeException(ErrorEval.getText(cellValue.getErrorValue())); 
   default: 
    throw new RuntimeException("unexpected
cell type " + cellValue.getCellTypeEnum()); 
  } 
 } catch (RuntimeException e) { 
  throw new RuntimeException("Could not evaluate the value of " + cell.getAddress() + " in sheet " + cell.getSheet().getSheetName(), e);
 }
}

Answer 1

为org/apache/poi/ss/formula/functions/TextFunction.java提供补丁

当然，我的第一个答案只是纠正症状。最终的解决方案显然应该是评估 TEXT 函数应该考虑不同的语言环境。

工作草案：

更改org/apache/poi/ss/formula/functions/TextFunction.java如下：

...
    /**
     * An implementation of the TEXT function<br>
     * TEXT returns a number value formatted with the given number formatting string. 
     * This function is not a complete implementation of the Excel function, but
     *  handles most of the common cases. All work is passed down to 
     *  {@link DataFormatter} to be done, as this works much the same as the
     *  display focused work that that does. 
     *
     * <b>Syntax<b>:<br> <b>TEXT</b>(<b>value</b>, <b>format_text</b>)<br>
     */
    public static final Function TEXT = new Fixed2ArgFunction() {

        public ValueEval evaluate(int srcRowIndex, int srcColumnIndex, ValueEval arg0, ValueEval arg1) {
            double s0;
            String s1;
            try {
                s0 = evaluateDoubleArg(arg0, srcRowIndex, srcColumnIndex);
                s1 = evaluateStringArg(arg1, srcRowIndex, srcColumnIndex);
            } catch (EvaluationException e) {
                return e.getErrorEval();
            }

            try {
            // Correct locale dependent format strings
                Locale locale = org.apache.poi.util.LocaleUtil.getUserLocale();
                if ("de".equals(locale.getLanguage())) {
                    s1 = s1.replace("T", "D"); // Tag = Day
                    // Monat = Month
                    s1 = s1.replace("J", "Y"); // Jahr = Year
                    //... further replacements
                } else if ("fr".equals(locale.getLanguage())) {
                    s1 = s1.replace("J", "D"); // Jour = Day
                    // Mois = Month
                    s1 = s1.replace("A", "Y"); // Année = Year
                    //... further replacements
                } //... further languages

            // Ask DataFormatter to handle the String for us
                String formattedStr = formatter.formatRawCellContents(s0, -1, s1);
                return new StringEval(formattedStr);
            } catch (Exception e) {
                return ErrorEval.VALUE_INVALID;
            }
        }
    };
...

那么获取内容就这么简单：

import org.apache.poi.ss.usermodel.*;
import org.apache.poi.ss.usermodel.CellType;
import org.apache.poi.ss.util.*;
import org.apache.poi.util.LocaleUtil;

import java.io.FileInputStream;
import java.util.Locale;

class ExcelEvaluateDiffLocales {

 private static String getString(Cell cell, DataFormatter formatter, FormulaEvaluator evaluator) {
  String text = "";
  if (cell.getCellType() == CellType.FORMULA) {
   String cellFormula = cell.getCellFormula();
   text += cellFormula + ":= ";
  }
  try {
   text += formatter.formatCellValue(cell, evaluator);
  } catch (org.apache.poi.ss.formula.eval.NotImplementedException ex) {
   text += ex.toString();
  }
  return text;
 }

 public static void main(String[] args) throws Exception {

  //Workbook wb  = WorkbookFactory.create(new FileInputStream("SAMPLE.xls"));
  Workbook wb  = WorkbookFactory.create(new FileInputStream("SAMPLE.xlsx"));

  Locale locale = new Locale("fr", "FR");
  LocaleUtil.setUserLocale(locale);
  DataFormatter formatter = new DataFormatter();
  FormulaEvaluator evaluator = wb.getCreationHelper().createFormulaEvaluator();

  Sheet sheet = wb.getSheetAt(0);
  for (Row row : sheet) {
   for (Cell cell : row) {
    CellReference cellRef = new CellReference(row.getRowNum(), cell.getColumnIndex());
    System.out.print(cellRef.formatAsString());
    System.out.print(" - ");

    String text = "";
    text = getString(cell, formatter, evaluator);

    System.out.println(text);

   }
  }

  wb.close();

 }
}

Answer 2

仅当使用的Excel 不是英文时才会出现此问题。那么这个公式不是真的=TEXT(A2,"yyyy-MM-dd")，而是我的德语Excel中的=TEXT(A2,"JJJJ-MM-TT")。

如您所见，TEXT 函数中的格式部分将始终依赖于区域设置，尽管所有其他公式部分始终是 en_US 区域设置。这是因为该格式部分位于公式中的字符串中，不会更改。所以在德语中是 =TEXT(A2,"JJJJ-MM-TT") (Year = Jahr, Day = Tag)，在法语中是 =TEXT(A2,"AAAA-MM-JJ") (Year = Année, Day = Jour)。

而且由于 apache poi 的 FormulaEvaluator 直到现在还没有区域设置，因此无法正确评估该公式。

那么我们有两种可能。

首先，我们希望存储的单元格值应该是所需的字符串。因此，如果单元格公式以“TEXT”开头并包含“JJJJ-MM-TT”，则不要评估，因为这将不正确。而是从Excel 的最后一次评估中获取字符串单元格值。

其次，我们可以用公式中的 en_US 替换区域设置相关格式部分，然后让apache poi 进行评估。至少如果我们只想读取而不是重写 Excel 文件，这不会破坏 Excel 文件中的内容。

---

代码优先方法：

import org.apache.poi.ss.usermodel.*;
import org.apache.poi.ss.usermodel.CellType;
import org.apache.poi.ss.util.*;

import org.apache.poi.ss.formula.eval.ErrorEval;

import java.io.FileInputStream;

class ReadExcelExample {

 private static String getString(Cell cell, FormulaEvaluator evaluator) {
  if (cell == null) return "null";
  String text = "";
  switch (cell.getCellType()) {
  //switch (cell.getCellTypeEnum()) {
   case STRING:
    text = cell.getRichStringCellValue().getString();
   break;
   case NUMERIC:
    if (DateUtil.isCellDateFormatted(cell)) {
     text = String.valueOf(cell.getDateCellValue());
    } else {
     text = String.valueOf(cell.getNumericCellValue());
    }
   break;
   case BOOLEAN:
    text = String.valueOf(cell.getBooleanCellValue());
   break;
   case FORMULA:
    text = cell.getCellFormula();

    //if formula is TEXT(...,"JJJJ-MM-TT") then do not evaluating:
    if (cell.getCellFormula().startsWith("TEXT") && cell.getCellFormula().contains("JJJJ-MM-TT")) {
     text = text + ": value got from cell = " + cell.getRichStringCellValue().getString();

    } else {
     CellValue cellValue = evaluator.evaluate(cell); 
     switch (cellValue.getCellType()) {
     //switch (cellValue.getCellTypeEnum()) {
      case STRING:
       text = text + ": " + cellValue.getStringValue();
      break;
      case NUMERIC:
       if (DateUtil.isCellDateFormatted(cell)) {
        text = text + ": " + String.valueOf(DateUtil.getJavaDate(cellValue.getNumberValue()));
       } else {
        text = text + ": " + String.valueOf(cellValue.getNumberValue());
       }
      break;
      case BOOLEAN:
       text = text + ": " + String.valueOf(cellValue.getBooleanValue());
      break;
      case ERROR:
       throw new RuntimeException("from CellValue: " + ErrorEval.getText(cellValue.getErrorValue()));
      default:
       throw new RuntimeException("unexpected cellValue type " + cellValue.getCellType()); 
     }
    }
   break;
   case ERROR:
    throw new RuntimeException("from Cell: " + ErrorEval.getText(cell.getErrorCellValue())); 
   case BLANK:
    text = "";
   break;
   default:
    throw new RuntimeException("unexpected cell type " + cell.getCellType());
  }

  return text;
 }

 public static void main(String[] args) throws Exception {

  //Workbook wb  = WorkbookFactory.create(new FileInputStream("SAMPLE.xls"));
  Workbook wb  = WorkbookFactory.create(new FileInputStream("SAMPLE.xlsx"));

  DataFormatter formatter = new DataFormatter(new java.util.Locale("en", "US"));
  FormulaEvaluator evaluator = wb.getCreationHelper().createFormulaEvaluator();

  Sheet sheet = wb.getSheetAt(0);
  for (Row row : sheet) {
   for (Cell cell : row) {
    CellReference cellRef = new CellReference(row.getRowNum(), cell.getColumnIndex());
    System.out.print(cellRef.formatAsString());
    System.out.print(" - ");

    String text = "";
    try {
    text = getString(cell, evaluator);
    } catch (Exception ex) {
     text = ex.toString();
    }
    System.out.println(text);

   }
  }

  wb.close();

 }
}

德语 Excel：

结果：

A1 - Value
B1 - Formula
A2 - Fri Jan 11 00:00:00 CET 2019
B2 - TEXT(A2,"JJJJ-MM-TT"): value got from cell = 2019-01-11
A3 - 123.45
B3 - A3*2: 246.9
B4 - java.lang.RuntimeException: from CellValue: #DIV/0!
B5 - TODAY(): Fri Jan 11 00:00:00 CET 2019
B6 - B5=A2: true
A7 - java.lang.RuntimeException: from CellValue: #N/A
B8 - TEXT(TODAY(),"JJJJ-MM-TT"): value got from cell = 2019-01-11

英文计算器：

结果：

A1 - Value
B1 - Formula
A2 - Fri Jan 11 00:00:00 CET 2019
B2 - TEXT(A2,"yyyy-MM-dd"): 2019-01-11
A3 - 123.45
B3 - A3*2: 246.9
B4 - java.lang.RuntimeException: from CellValue: #DIV/0!
B5 - TODAY(): Fri Jan 11 00:00:00 CET 2019
B6 - B5=A2: true
A7 - java.lang.RuntimeException: from CellValue: #N/A
B8 - TEXT(TODAY(),"yyyy-MM-dd"): 2019-01-11

---

代码第二种方法（将依赖于语言环境的格式部分替换为 en_US 格式部分）：

import org.apache.poi.ss.usermodel.*;
import org.apache.poi.ss.usermodel.CellType;
import org.apache.poi.ss.util.*;

import java.io.FileInputStream;
import java.util.Locale;

class ExcelEvaluateTEXTDiffLocales {

 private static String getString(Cell cell, DataFormatter formatter, FormulaEvaluator evaluator, Locale locale) {
  String text = "";
  if (cell.getCellType() == CellType.FORMULA) {
   String cellFormula = cell.getCellFormula();
   text += cellFormula + ":= ";

   if (cellFormula.startsWith("TEXT")) {
    int startFormatPart = cellFormula.indexOf('"');
    int endFormatPart = cellFormula.lastIndexOf('"') + 1;
    String formatPartOld = cellFormula.substring(startFormatPart, endFormatPart);
    String formatPartNew = formatPartOld;
    if ("de".equals(locale.getLanguage())) {
     formatPartNew = formatPartNew.replace("T", "D"); // Tag = Day
     // Monat = Month
     formatPartNew = formatPartNew.replace("J", "Y"); // Jahr = Year
     //...
    } else if ("fr".equals(locale.getLanguage())) {
     formatPartNew = formatPartNew.replace("J", "D"); // Jour = Day
     // Mois = Month
     formatPartNew = formatPartNew.replace("A", "Y"); // Année = Year
     //...
    } //...
    cellFormula = cellFormula.replace(formatPartOld, formatPartNew);
    cell.setCellFormula(cellFormula);
   }

  }
  try {
   text += formatter.formatCellValue(cell, evaluator);
  } catch (org.apache.poi.ss.formula.eval.NotImplementedException ex) {
   text += ex.toString();
  }

  return text;
 }

 public static void main(String[] args) throws Exception {

  //Workbook wb  = WorkbookFactory.create(new FileInputStream("SAMPLE.xls"));
  Workbook wb  = WorkbookFactory.create(new FileInputStream("SAMPLE.xlsx"));

  Locale locale = new Locale("fr", "CH");
  DataFormatter formatter = new DataFormatter(locale);
  FormulaEvaluator evaluator = wb.getCreationHelper().createFormulaEvaluator();

  Sheet sheet = wb.getSheetAt(0);
  for (Row row : sheet) {
   for (Cell cell : row) {
    CellReference cellRef = new CellReference(row.getRowNum(), cell.getColumnIndex());
    System.out.print(cellRef.formatAsString());
    System.out.print(" - ");

    String text = "";
    text = getString(cell, formatter, evaluator, locale);

    System.out.println(text);

   }
  }

  wb.close();

 }
}

法语计算器：

结果：

A1 - Value
B1 - Formula
A2 - 1/11/2019
B2 - TEXT(A2,"AAAA-MM-JJ"):= 2019-01-11
A3 - 123.45
B3 - A3*2:= 246.9
B4 - 1/A4:= #DIV/0!
B5 - TODAY():= 1/12/2019
B6 - B5=A2:= FALSE
A7 - NA():= #N/A
B8 - TEXT(TODAY(),"AAAA-MM-JJ"):= 2019-01-12

提示：这里使用的apache poi 版本是4.0.1。也许较低的版本可能会有进一步的评估问题。