Package freemarker.core

Class ArithmeticEngine

java.lang.Object
freemarker.core.ArithmeticEngine
Direct Known Subclasses:
ArithmeticEngine.BigDecimalEngine, ArithmeticEngine.ConservativeEngine
public abstract class ArithmeticEngine extends Object
Used for implementing the arithmetic operations and number comparisons in the template language. The concrete implementation is plugged into the configuration with the arithmetical_engine setting. (See Configurable.setArithmeticEngine(ArithmeticEngine).)

  • Field Details

    • BIGDECIMAL_ENGINE

      public static final ArithmeticEngine.BigDecimalEngine BIGDECIMAL_ENGINE
      Arithmetic engine that converts all numbers to BigDecimal and then operates on them, and also keeps the result as a BigDecimal. This is FreeMarker's default arithmetic engine.

    • CONSERVATIVE_ENGINE

      public static final ArithmeticEngine.ConservativeEngine CONSERVATIVE_ENGINE
      Arithmetic engine that uses (more-or-less) the widening conversions of Java language to determine the type of result of operation, instead of converting everything to BigDecimal up front.

    • minScale

      protected int minScale

    • maxScale

      protected int maxScale

    • roundingPolicy

      protected int roundingPolicy

  • Constructor Details

    • ArithmeticEngine

      public ArithmeticEngine()

  • Method Details

    • compareNumbers

      public abstract int compareNumbers​(Number first, Number second) throws TemplateException
      Throws:
      TemplateException

    • add

      public abstract Number add​(Number first, Number second) throws TemplateException
      Throws:
      TemplateException

    • subtract

      public abstract Number subtract​(Number first, Number second) throws TemplateException
      Throws:
      TemplateException

    • multiply

      public abstract Number multiply​(Number first, Number second) throws TemplateException
      Throws:
      TemplateException

    • divide

      public abstract Number divide​(Number first, Number second) throws TemplateException
      Throws:
      TemplateException

    • modulus

      public abstract Number modulus​(Number first, Number second) throws TemplateException
      Throws:
      TemplateException

    • toNumber

      public abstract Number toNumber​(String s)
      Should be able to parse all FTL numerical literals, Java Double toString results, and XML Schema numbers. This means these should be parsed successfully, except if the arithmetical engine couldn't support the resulting value anyway (such as NaN, infinite, even non-integers): -123.45, 1.5e3, 1.5E3, 0005, +0, -0, NaN, INF, -INF, Infinity, -Infinity.

    • hexadecimalToNumber

      public Number hexadecimalToNumber​(String s)
      Parses a hexadecimal number like "0xCAFEBABE". The template language parser restricts what needs to be supported here:
      • Parsing must be case-insensitive
      • There's never a sign (plus or minus); if there's a minus sign, that will be handled outside this method
      • The string always starts with 0x (or 0X), so you can safely ignore the first 2 characters
      • There's an arbitrary number of digits
      • Only whole numbers need to be supported (there's never a . in the string)

      Default implementation in ArithmeticEngine chooses the smallest type that can still represent the number (always positive) without loss: Integer, Long, BigInteger

      Since:
      2.3.35

    • setMinScale

      public void setMinScale​(int minScale)
      Sets the minimal scale to use when dividing BigDecimal numbers. Default value is 12.

    • setMaxScale

      public void setMaxScale​(int maxScale)
      Sets the maximal scale to use when multiplying BigDecimal numbers. Default value is 100.

    • setRoundingPolicy

      public void setRoundingPolicy​(int roundingPolicy)