Class DefaultPrimeMeridian

All Implemented Interfaces:
Serializable, Formattable, Deprecable, Lenient­Comparable, Printable, Prime­Meridian, Identified­Object

public class DefaultPrimeMeridian extends AbstractIdentifiedObject implements PrimeMeridian
Defines the origin from which longitude values are determined.

Creating new prime meridian instances

New instances can be created either directly by specifying all information to a factory method (choices 3 and 4 below), or indirectly by specifying the identifier of an entry in a database (choices 1 and 2 below). In particular, the EPSG repository provides definitions for many prime meridians, and Apache SIS provides convenience shortcuts for some of them.

Choice 1 in the following list is the easiest but most restrictive way to get a prime meridian. The other choices provide more freedom. Each choice delegates its work to the subsequent items (in the default configuration), so this list can be seen as top to bottom API.

  1. Create a Prime­Meridian from one of the static convenience shortcuts listed in Common­CRS​.prime­Meridian().
  2. Create a Prime­Meridian from an identifier in a database by invoking Datum­Authority­Factory​.create­Prime­Meridian(String).
  3. Create a Prime­Meridian by invoking the Datum­Factory​.create­Prime­Meridian(…) method (implemented for example by Geodetic­Object­Factory).
  4. Create a Default­Prime­Meridian by invoking the constructor.
Example: the following code gets the Greenwich prime meridian:
PrimeMeridian pm = CommonCRS.WGS84.primeMeridian();

Immutability and thread safety

This class is immutable and thus thread-safe if the property values (not necessarily the map itself) given to the constructor are also immutable. Unless otherwise noted in the javadoc, this condition holds if all components were created using only SIS factories and static constants.
Since:
0.4
See Also: