Class DataFormatter

java.lang.Object
org.apache.poi.ss.usermodel.DataFormatter
All Implemented Interfaces:
Observer
Direct Known Subclasses:
HSSFDataFormatter

public class DataFormatter extends Object implements Observer
DataFormatter contains methods for formatting the value stored in an Cell. This can be useful for reports and GUI presentations when you need to display data exactly as it appears in Excel. Supported formats include currency, SSN, percentages, decimals, dates, phone numbers, zip codes, etc.

Internally, formats will be implemented using subclasses of Format such as DecimalFormat and SimpleDateFormat. Therefore the formats used by this class must obey the same pattern rules as these Format subclasses. This means that only legal number pattern characters ("0", "#", ".", "," etc.) may appear in number formats. Other characters can be inserted before or after the number pattern to form a prefix or suffix.

For example the Excel pattern "$#,##0.00 "USD"_);($#,##0.00 "USD")" will be correctly formatted as "$1,000.00 USD" or "($1,000.00 USD)". However the pattern "00-00-00" is incorrectly formatted by DecimalFormat as "000000--". For Excel formats that are not compatible with DecimalFormat, you can provide your own custom Format implementation via DataFormatter.addFormat(String,Format). The following custom formats are already provided by this class:

 
  • SSN "000-00-0000"
  • Phone Number "(###) ###-####"
  • Zip plus 4 "00000-0000"

If the Excel format pattern cannot be parsed successfully, then a default format will be used. The default number format will mimic the Excel General format: "#" for whole numbers and "#.##########" for decimal numbers. You can override the default format pattern with DataFormatter.setDefaultNumberFormat(Format). Note: the default format will only be used when a Format cannot be created from the cell's data format string.

Note that by default formatted numeric values are trimmed. Excel formats can contain spacers and padding and the default behavior is to strip them off.

Example:

Consider a numeric cell with a value 12.343 and format "##.##_ ". The trailing underscore and space ("_ ") in the format adds a space to the end and Excel formats this cell as "12.34 ", but DataFormatter trims the formatted value and returns "12.34".

You can enable spaces by passing the emulateCSV=true flag in the DateFormatter cosntructor. If set to true, then the output tries to conform to what you get when you take an xls or xlsx in Excel and Save As CSV file:
  • returned values are not trimmed
  • Invalid dates are formatted as 255 pound signs ("#")
  • simulate Excel's handling of a format string of all # when the value is 0. Excel will output "", DataFormatter will output "0".

Some formats are automatically "localized" by Excel, eg show as mm/dd/yyyy when loaded in Excel in some Locales but as dd/mm/yyyy in others. These are always returned in the "default" (US) format, as stored in the file. Some format strings request an alternate locale, eg [$-809]d/m/yy h:mm AM/PM which explicitly requests UK locale. These locale directives are (currently) ignored. You can use DateFormatConverter to do some of this localisation if you need it.

  • Constructor Details

    • DataFormatter

      public DataFormatter()
      Creates a formatter using the default locale.
    • DataFormatter

      public DataFormatter(boolean emulateCSV)
      Creates a formatter using the default locale.
      Parameters:
      emulateCSV - whether to emulate CSV output.
    • DataFormatter

      public DataFormatter(Locale locale)
      Creates a formatter using the given locale.
    • DataFormatter

      public DataFormatter(Locale locale, boolean emulateCSV)
      Creates a formatter using the given locale.
      Parameters:
      emulateCSV - whether to emulate CSV output.
    • DataFormatter

      public DataFormatter(Locale locale, boolean localeIsAdapting, boolean emulateCSV)
      Creates a formatter using the given locale.
      Parameters:
      localeIsAdapting - (true only if locale is not user-specified)
      emulateCSV - whether to emulate CSV output.
  • Method Details

    • createFormat

      public Format createFormat(Cell cell)
      Create and return a Format based on the format string from a cell's style. If the pattern cannot be parsed, return a default pattern.
      Parameters:
      cell - The Excel cell
      Returns:
      A Format representing the excel format. May return null.
    • getDefaultFormat

      public Format getDefaultFormat(Cell cell)
      Returns a default format for a cell.
      Parameters:
      cell - The cell
      Returns:
      a default format
    • formatRawCellContents

      public String formatRawCellContents(double value, int formatIndex, String formatString)
      Formats the given raw cell value, based on the supplied format index and string, according to excel style rules.
      See Also:
    • formatRawCellContents

      public String formatRawCellContents(double value, int formatIndex, String formatString, boolean use1904Windowing)
      Formats the given raw cell value, based on the supplied format index and string, according to excel style rules.
      See Also:
    • formatCellValue

      public String formatCellValue(Cell cell)

      Returns the formatted value of a cell as a String regardless of the cell type. If the Excel format pattern cannot be parsed then the cell value will be formatted using a default format.

      When passed a null or blank cell, this method will return an empty String (""). Formulas in formula type cells will not be evaluated.

      Parameters:
      cell - The cell
      Returns:
      the formatted cell value as a String
    • formatCellValue

      public String formatCellValue(Cell cell, FormulaEvaluator evaluator)

      Returns the formatted value of a cell as a String regardless of the cell type. If the Excel number format pattern cannot be parsed then the cell value will be formatted using a default format.

      When passed a null or blank cell, this method will return an empty String (""). Formula cells will be evaluated using the given FormulaEvaluator if the evaluator is non-null. If the evaluator is null, then the formula String will be returned. The caller is responsible for setting the currentRow on the evaluator

      Parameters:
      cell - The cell (can be null)
      evaluator - The FormulaEvaluator (can be null)
      Returns:
      a string value of the cell
    • formatCellValue

      public String formatCellValue(Cell cell, FormulaEvaluator evaluator, ConditionalFormattingEvaluator cfEvaluator)

      Returns the formatted value of a cell as a String regardless of the cell type. If the Excel number format pattern cannot be parsed then the cell value will be formatted using a default format.

      When passed a null or blank cell, this method will return an empty String (""). Formula cells will be evaluated using the given FormulaEvaluator if the evaluator is non-null. If the evaluator is null, then the formula String will be returned. The caller is responsible for setting the currentRow on the evaluator

      When a ConditionalFormattingEvaluator is present, it is checked first to see if there is a number format to apply. If multiple rules apply, the last one is used. If no ConditionalFormattingEvaluator is present, no rules apply, or the applied rules do not define a format, the cell's style format is used.

      The two evaluators should be from the same context, to avoid inconsistencies in cached values.

      Parameters:
      cell - The cell (can be null)
      evaluator - The FormulaEvaluator (can be null)
      cfEvaluator - ConditionalFormattingEvaluator (can be null)
      Returns:
      a string value of the cell
    • setDefaultNumberFormat

      public void setDefaultNumberFormat(Format format)

      Sets a default number format to be used when the Excel format cannot be parsed successfully. Note: This is a fall back for when an error occurs while parsing an Excel number format pattern. This will not affect cells with the General format.

      The value that will be passed to the Format's format method (specified by java.text.Format#format) will be a double value from a numeric cell. Therefore the code in the format method should expect a Number value.

      Parameters:
      format - A Format instance to be used as a default
      See Also:
    • addFormat

      public void addFormat(String excelFormatStr, Format format)
      Adds a new format to the available formats.

      The value that will be passed to the Format's format method (specified by java.text.Format#format) will be a double value from a numeric cell. Therefore the code in the format method should expect a Number value.

      Parameters:
      excelFormatStr - The data format string
      format - A Format instance
    • setExcelStyleRoundingMode

      public static void setExcelStyleRoundingMode(DecimalFormat format)
      Enables excel style rounding mode (round half up) on the Decimal Format given.
    • setExcelStyleRoundingMode

      public static void setExcelStyleRoundingMode(DecimalFormat format, RoundingMode roundingMode)
      Enables custom rounding mode on the given Decimal Format.
      Parameters:
      format - DecimalFormat
      roundingMode - RoundingMode
    • getLocaleChangedObservable

      public Observable getLocaleChangedObservable()
      If the Locale has been changed via LocaleUtil.setUserLocale(Locale) the stored formats need to be refreshed. All formats which aren't originated from DataFormatter itself, i.e. all Formats added via addFormat(String, Format) and setDefaultNumberFormat(Format), need to be added again. To notify callers, the returned Observable should be used. The Object in Observer.update(Observable, Object) is the new Locale.
      Returns:
      the listener object, where callers can register themselves
    • update

      public void update(Observable observable, Object localeObj)
      Update formats when locale has been changed
      Specified by:
      update in interface Observer
      Parameters:
      observable - usually this is our own Observable instance
      localeObj - only reacts on Locale objects