Units of Measure (UOM)

Immutable record holding a value paired with a unit-of-measure code. Carries assertion helpers (assertHasUomType, assertHasUomTypeAndExponent) so callers can verify that a quantity is in the expected dimension before using it.

Quantity that additionally tracks a piece count. Used when an item is sold by weight or volume but also exists as discrete units (for example "5 kg comprising 20 pieces"). toSiQuantity() strips the piece count when only the dimensional part is needed.

A parsed two-component compound unit such as kg/m3 or g m^-3. Instances are cached by uomCode for the lifetime of the JVM since parsing is pure.

A compound unit paired with a numeric value, used as the result of compound conversions.

A single parsed unit, optionally prefixed and exponentiated. Cached by uomCode.

A single unit paired with a numeric value, used as the result of single-unit conversions.

Enum listing every unit the submodule recognises (PCS, AMPERE, CANDELA, KELVIN, CENTIGRADE, GRAM, TONNE, METER, LITER, MOLE, SECOND, plus imperial: FAHRENHEIT, OUNCE, POUND, STONE, TON, INCH, FOOT, YARD, FURLONG, MILE, FLUID_OUNCE, GALLON). Each value carries its conversion factor to its base unit, its base-unit signature, and the symbols accepted on parse.

The base-unit fingerprint of a SiUom. Two units are convertible only when their signatures match. A signature is a list of (SiUomBase, exponent) items — typically one item, with two used for compound-derived units.

Enum of the nine base units the system reduces everything to. Each base value carries a symbol and the dimensional SiUomType it represents.

Enum naming the physical dimension a base unit measures.

Enum listing the SI prefixes recognised on parse, with their decimal multipliers and symbols.

METRIC or IMPERIAL — used by callers that want to pick a unit set for a country or product class.

ADD, SUBTRACT, MULTIPLY, DIVIDE — selects the arithmetic combination performed by SiUomCalculationUtil.calculateQuantities.

SiUomSingleUomUtil converts a SiQuantity (or a raw value/uomCode pair) between two single-unit codes. The conversion goes through the base unit: the source value is reduced to its base via the unit’s factorToBaseUnit and prefix multiplier, then expanded into the target. convertToSiUomIfConvertable returns null instead of raising when the dimensions do not match — useful when callers want to fall through to an alternative.

SiUomCompoundUtil.convertToSiUomBase parses a compound unit code such as kg/m3 into two SiUomSingle components, requires that the first component has a non-negative exponent and the second a non-positive exponent, and reduces the value to the equivalent base-unit compound (e.g. g/m3). Compound units with shapes other than two components raise a business exception.

SiUomCalculationUtil.calculateQuantities adds, subtracts, multiplies, or divides two SiQuantity values whose base units agree, returning the result expressed in a caller-supplied target unit. Both quantities are first reduced to their base unit so that, for example, 1 kg + 500 g returns the expected mass. Division by zero raises a business exception.

The same utility class hosts higher-level helpers used by the trade and inventory flows:

SiUomUtil.assertHasUomTypeAndExponent and the matching helpers on SiQuantity raise a business exception when a quantity’s dimension or exponent does not match the expected one. They are used pervasively at the entry of every calculation helper so failures point at the offending input.

SiUomPreprocessor rewrites convenience forms before parsing: it splits a numerator/denominator compound, expands trailing-digit forms (m2 → m^2, m3 → m^3), and applies a negative exponent sign to the denominator. The parsed forms feed both SiUomSingle.of and SiUomCompound.of, both of which cache their results.

The submodule does not provide a query or command API class. Other modules call the static utility classes directly:

The submodule does not expose any UI; it is consumed exclusively from server-side code. There are no view models or actions to document.

There is no bootstrap class — the recognised units, prefixes, and base units are declared as Java enums and are available from JVM start without any database state.