content: package com.alibaba.excel.metadata.format;
  
  import java.math.BigDecimal;
  import java.math.MathContext;
  import java.math.RoundingMode;
  import java.text.DecimalFormat;
  import java.text.DecimalFormatSymbols;
  import java.text.FieldPosition;
  import java.text.Format;
  import java.text.ParsePosition;
  import java.util.Locale;
  
  import org.apache.poi.ss.usermodel.DataFormatter;
  
  /**
   * Written with reference to {@link org.apache.poi.ss.usermodel.ExcelGeneralNumberFormat }.
   * <p>
   * Supported Do not use scientific notation.
   *
   * @author JiaJu Zhuang
   **/
  public class ExcelGeneralNumberFormat extends Format {
  
      private static final long serialVersionUID = 1L;
  
      private static final MathContext TO_10_SF = new MathContext(10, RoundingMode.HALF_UP);
  
      private final DecimalFormatSymbols decimalSymbols;
      private final DecimalFormat integerFormat;
      private final DecimalFormat decimalFormat;
      private final DecimalFormat scientificFormat;
  
      public ExcelGeneralNumberFormat(final Locale locale, final boolean useScientificFormat) {
          decimalSymbols = DecimalFormatSymbols.getInstance(locale);
          //  Supported Do not use scientific notation.
          if (useScientificFormat) {
              scientificFormat = new DecimalFormat("0.#####E0", decimalSymbols);
          } else {
              scientificFormat = new DecimalFormat("#", decimalSymbols);
          }
          org.apache.poi.ss.usermodel.DataFormatter.setExcelStyleRoundingMode(scientificFormat);
          integerFormat = new DecimalFormat("#", decimalSymbols);
          org.apache.poi.ss.usermodel.DataFormatter.setExcelStyleRoundingMode(integerFormat);
          decimalFormat = new DecimalFormat("#.##########", decimalSymbols);
          DataFormatter.setExcelStyleRoundingMode(decimalFormat);
      }
  
      @Override
      public StringBuffer format(Object number, StringBuffer toAppendTo, FieldPosition pos) {
          final double value;
          if (number instanceof Number) {
              value = ((Number) number).doubleValue();
              if (Double.isInfinite(value) || Double.isNaN(value)) {
                  return integerFormat.format(number, toAppendTo, pos);
              }
          } else {
              // testBug54786 gets here with a date, so retain previous behaviour
              return integerFormat.format(number, toAppendTo, pos);
          }
  
          final double abs = Math.abs(value);
          if (abs >= 1E11 || (abs <= 1E-10 && abs > 0)) {
              return scientificFormat.format(number, toAppendTo, pos);
          } else if (Math.floor(value) == value || abs >= 1E10) {
              // integer, or integer portion uses all 11 allowed digits
              return integerFormat.format(number, toAppendTo, pos);
          }
          // Non-integers of non-scientific magnitude are formatted as "up to 11
          // numeric characters, with the decimal point counting as a numeric
          // character". We know there is a decimal point, so limit to 10 digits.
          // https://support.microsoft.com/en-us/kb/65903
          final double rounded = new BigDecimal(value).round(TO_10_SF).doubleValue();
          return decimalFormat.format(rounded, toAppendTo, pos);
      }
  
      @Override
      public Object parseObject(String source, ParsePosition pos) {
          throw new UnsupportedOperationException();
      }
  
  }
  