Class MathUtils

java.lang.Object
org.apache.velocity.runtime.parser.node.MathUtils

public abstract class MathUtils extends Object
Utility-class for all arithmetic-operations.

All operations (+ - / *) return a Number which type is the type of the bigger argument.
Example:
add ( new Integer(10), new Integer(1)) will return an Integer-Object with the value 11
add ( new Long(10), new Integer(1)) will return an Long-Object with the value 11
add ( new Integer(10), new Float(1)) will return an Float-Object with the value 11

Overflow checking:
For integral values (byte, short, int) there is an implicit overflow correction (the next "bigger" type will be returned). For example, if you call add (new Integer (Integer.MAX_VALUE), 1) a Long-object will be returned with the correct value of Integer.MAX_VALUE+1.
In addition to that the methods multiply,add and substract implement overflow checks for long-values. That means that if an overflow occurs while working with long values a BigInteger will be returned.
For all other operations and types (such as Float and Double) there is no overflow checking.
Since:
1.5
  • Field Details

    • DECIMAL_ZERO

      protected static final BigDecimal DECIMAL_ZERO
      A BigDecimal representing the number 0
    • BASE_LONG

      protected static final int BASE_LONG
      The constants are used to determine in which context we have to calculate.
      See Also:
    • BASE_FLOAT

      protected static final int BASE_FLOAT
      See Also:
    • BASE_DOUBLE

      protected static final int BASE_DOUBLE
      See Also:
    • BASE_BIGINTEGER

      protected static final int BASE_BIGINTEGER
      See Also:
    • BASE_BIGDECIMAL

      protected static final int BASE_BIGDECIMAL
      See Also:
    • ints

      protected static final Map ints
      The Class-object is key, the maximum-value is the value
    • typesBySize

      protected static final List typesBySize
      The "size" of the number-types - ascending.
  • Constructor Details

    • MathUtils

      public MathUtils()
  • Method Details

    • toBigDecimal

      public static BigDecimal toBigDecimal(Number n)
      Convert the given Number to a BigDecimal
      Parameters:
      n -
      Returns:
      The number as BigDecimal
    • toBigInteger

      public static BigInteger toBigInteger(Number n)
      Convert the given Number to a BigInteger
      Parameters:
      n -
      Returns:
      The number as BigInteger
    • isZero

      public static boolean isZero(Number n)
      Compare the given Number to 0.
      Parameters:
      n -
      Returns:
      True if number is 0.
    • isInteger

      public static boolean isInteger(Number n)
      Test, whether the given object is an integer value (Byte, Short, Integer, Long, BigInteger)
      Parameters:
      n -
      Returns:
      True if n is an integer.
    • wrapPrimitive

      public static Number wrapPrimitive(long value, Class type)
      Wrap the given primitive into the given class if the value is in the range of the destination type. If not the next bigger type will be chosen.
      Parameters:
      value -
      type -
      Returns:
      Number object representing the primitive.
    • wrapPrimitive

      private static Number wrapPrimitive(long value, Number op1, Number op2)
      Wrap the result in the object of the bigger type.
      Parameters:
      value - result of operation (as a long) - used to check size
      op1 - first operand of binary operation
      op2 - second operand of binary operation
      Returns:
      Number object of appropriate size to fit the value and operators
    • findCalculationBase

      private static int findCalculationBase(Number op1, Number op2)
      Find the common Number-type to be used in calculations.
      Parameters:
      op1 - first operand of binary operation
      op2 - second operand of binary operation
      Returns:
      constant indicating type of Number to use in calculations
    • add

      public static Number add(Number op1, Number op2)
      Add two numbers and return the correct value / type. Overflow detection is done for integer values (byte, short, int, long) only!
      Parameters:
      op1 -
      op2 -
      Returns:
      Addition result.
    • subtract

      public static Number subtract(Number op1, Number op2)
      Subtract two numbers and return the correct value / type. Overflow detection is done for integer values (byte, short, int, long) only!
      Parameters:
      op1 -
      op2 -
      Returns:
      Subtraction result.
    • multiply

      public static Number multiply(Number op1, Number op2)
      Multiply two numbers and return the correct value / type. Overflow detection is done for integer values (byte, short, int, long) only!
      Parameters:
      op1 -
      op2 -
      Returns:
      Multiplication result.
    • divide

      public static Number divide(Number op1, Number op2)
      Divide two numbers. The result will be returned as Integer-type if and only if both sides of the division operator are Integer-types. Otherwise a Float, Double, or BigDecimal will be returned.
      Parameters:
      op1 -
      op2 -
      Returns:
      Division result.
    • modulo

      public static Number modulo(Number op1, Number op2) throws ArithmeticException
      Modulo two numbers.
      Parameters:
      op1 -
      op2 -
      Returns:
      Modulo result.
      Throws:
      ArithmeticException - If at least one parameter is a BigDecimal
    • compare

      public static int compare(Number op1, Number op2)
      Compare two numbers.
      Parameters:
      op1 -
      op2 -
      Returns:
      1 if n1 > n2, -1 if n1 < n2 and 0 if equal.