UML to Java mapping

The following stereotypes of UML classes and data types are mapped to J2SE objects as below:

UML	OGC Purpose	Java mapping
`<<DataType>>`	A descriptor of a set of values that lack identity (independent existence and the possibility of side effects). A DataType is a class with no operations whose primary purpose is to hold the information.	Interface
`<<CodeList>>`	A flexible enumeration that uses string values for expressing a list of potential values.	`CodeList extends java.lang.Enum^*`
`<<Union>>`	Contains a list of attributes where only one of those attributes can be present at any time.	none
`<<Abstract>>`	A polymorphic object class that cannot be instantiated.	Interface
Constructor	Cast an object into an object of an other type.	A `createFoo()` method in a `Factory` interface.
`Set<DataType>`	A finite set. Each object is considered to be in the set only once.	`java.util.Set`
`Sequence<DataType>`	A sequence type of collection, which contains an ordered finite list of values (possibly with repeated values) of the specified data type.	Small array, or `java.util.List` if the sequence is likely to be big.
`CharacterString`	A sequence of characters.	`java.lang.String` in the general case, or `java.net.URL` for reference to a file.
`Integer`	An integer number.	`int`
`Double`	A double precision floating point number.	`double`
`Boolean`	A value specifying TRUE or FALSE.	`boolean`
`Sign`	Sign + or -.	`int` with value +1 ou -1
`DateTime`	A character string as specified by ISO 19108, which comprises year, month, day and time of the day to the appropriate level of precision.	`java.util.Date`
`Scale`	A floating point number associated with a dimensionless unit.	`double`
`Length`	A floating point number associated with a linear unit.	`double` with some `getUnit()` method (e.g. `getAxisUnit()`).
`Angle`	A floating point number associated with an angular unit.	`double` with some `getUnit()` method (e.g. `getAngularUnit()`).
`Measure`	A floating point number associated with an arbitrary unit.	`double` with a `getUnit()` method.

^* For platform earlier than J2SE 1.5, the CodeList class will defines the same attributes than Enum but will not extends Enum.

Custom Javadoc tags

OpenGIS's Mandatory, Conditional and Optional attributes are marked using custom @UML mandatory, @UML conditional and @UML optional javadoc tags respectively. Additional javadoc tags include @UML association and @UML datatype. All the above-cited tags imply some renaming rules in order to comply with Java naming conventions.

Javadoc tag	Usage and renaming rule
`@UML datatype`	Interfaces marked with this tag are "datatype" (as opposed to "abstract") in UML diagrams.
`@UML mandatory`	The Java method maps to a mandatory attribute in the UML diagram. The Java method name is prefixed by "`get`". For example, the mandatory "`code`" UML attribute maps to a `getCode()` Java method.
`@UML conditional`	The Java method maps to a conditional attribute in the UML diagram. The Java method name is prefixed by "`get`".
`@UML optional`	The Java method maps to an optional attribute in the UML diagram. The Java method name is prefixed by "`get`". For example, the optional "`remarks`" UML attribute maps to a `getRemarks()` Java method.
`@UML association`	The Java method maps to an association in the UML diagram. The UML's "`uses`" or "`includes`" prefix are omitted and the Java method name is prefixed by "`get`". For example, the `CoordinateSystem` class has a "`usesAxis`" association. In Java, associations map to ordinary methods. Consequently, the `usesAxis` association is mapped into a plain `getAxis()` method.
`@rename` `<reason>`	Some other name change has been applied in order to match more closely Java usage. A description of the change and its rational shall follow the `@rename` tag. There is two reasons for renaming: In some occasions, abbreviations are expanded. For example a `getCS()` method returning a `CoordinateSystem` object is renamed `getCoordinateSystem()`. In some occasions, supplementary prefix are omitted. For example, some UML attribute names are prefixed by some abbreviation of the enclosing class name (e.g. "`csName`" is `CoordinateSystem` and "`srsName`" in `ReferenceSystem`). For Java interfaces, the above-cited attributes map to a plain `getName()` method. The same apply to "`ID`". Methods returning an array are renamed to their plural form (e.g. `getElement()` to `getElements()`).
`@unitof` `<quantity>`	The method returns a `double` value which should be expressed in unit of `Scale`, `Length` or `Angle`. Some `getUnit()` method must be provided in addition to this method.
`@revisit` `<comment>`	Somme open issue to revisit.