Class CRSFactory

java.lang.Object

org.locationtech.proj4j.CRSFactory

public class CRSFactory
extends Object

A factory which can create CoordinateReferenceSystems from a variety of ways of specifying them. This is the primary way of creating coordinate systems for carrying out projections transformations.

CoordinateReferenceSystems can be used to define CoordinateTransforms to perform transformations on ProjCoordinates.

Field Summary

Fields

Modifier and Type	Field	Description
private static Proj4FileReader	csReader
private static Registry	registry

Constructor Summary

Constructors

Constructor	Description
CRSFactory()

Method Summary

Modifier and Type	Method	Description
CoordinateReferenceSystem	createFromName(String name)	Creates a CoordinateReferenceSystem (CRS) from a well-known name.
CoordinateReferenceSystem	createFromParameters(String name, String paramStr)	Creates a CoordinateReferenceSystem from a PROJ.4 projection parameter string.
CoordinateReferenceSystem	createFromParameters(String name, String[] params)	Creates a CoordinateReferenceSystem defined by an array of PROJ.4 projection parameters.
Registry	getRegistry()	Gets the Registry used by this factory.
String	readEpsgFromParameters(String paramStr)	Finds a EPSG Code from a PROJ.4 projection parameter string.
String	readEpsgFromParameters(String[] params)	Finds a EPSG Code defined by an array of PROJ.4 projection parameters.
private static String[]	splitParameters(String paramStr)

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

csReader

private static Proj4FileReader csReader

registry

private static Registry registry

Constructor Details

CRSFactory

public CRSFactory()

Method Details

getRegistry

public Registry getRegistry()

Gets the Registry used by this factory.

Returns:

the Registry

createFromName

public CoordinateReferenceSystem createFromName(String name)
                                         throws UnsupportedParameterException,
InvalidValueException,
UnknownAuthorityCodeException

Creates a CoordinateReferenceSystem (CRS) from a well-known name. CRS names are of the form: "authority:code", with the components being:

• authority is a code for a namespace supported by PROJ.4. Currently supported values are EPSG, ESRI, WORLD, NA83, NAD27. If no authority is provided, the EPSG namespace is assumed.
• code is the id of a coordinate system in the authority namespace. For example, in the EPSG namespace a code is an integer value which identifies a CRS definition in the EPSG database. (Codes are read and handled as strings).

An example of a valid CRS name is EPSG:3005.

Parameters:

name - the name of a coordinate system, with optional authority prefix

Returns:

the CoordinateReferenceSystem corresponding to the given name

Throws:

UnsupportedParameterException - if a PROJ.4 parameter is not supported

InvalidValueException - if a parameter value is invalid

UnknownAuthorityCodeException - if the authority code cannot be found

createFromParameters

public CoordinateReferenceSystem createFromParameters(String name,
 String paramStr)
                                               throws UnsupportedParameterException,
InvalidValueException

Creates a CoordinateReferenceSystem from a PROJ.4 projection parameter string.

An example of a valid PROJ.4 projection parameter string is:

+proj=aea +lat_1=50 +lat_2=58.5 +lat_0=45 +lon_0=-126 +x_0=1000000 +y_0=0 +ellps=GRS80 +units=m

Parameters:

name - a name for this coordinate system (may be null for an anonymous coordinate system)

paramStr - a PROJ.4 projection parameter string

Returns:

the specified CoordinateReferenceSystem

Throws:

UnsupportedParameterException - if a given PROJ.4 parameter is not supported

InvalidValueException - if a supplied parameter value is invalid

createFromParameters

public CoordinateReferenceSystem createFromParameters(String name,
 String[] params)
                                               throws UnsupportedParameterException,
InvalidValueException

Creates a CoordinateReferenceSystem defined by an array of PROJ.4 projection parameters. PROJ.4 parameters are generally of the form "+name=value".

Parameters:

name - a name for this coordinate system (may be null)

params - an array of PROJ.4 projection parameters

Returns:

a CoordinateReferenceSystem

Throws:

UnsupportedParameterException - if a PROJ.4 parameter is not supported

InvalidValueException - if a parameter value is invalid

readEpsgFromParameters

public String readEpsgFromParameters(String paramStr)
                              throws IOException

Finds a EPSG Code from a PROJ.4 projection parameter string.

An example of a valid PROJ.4 projection parameter string is:

+proj=aea +lat_1=50 +lat_2=58.5 +lat_0=45 +lon_0=-126 +x_0=1000000 +y_0=0 +ellps=GRS80 +units=m

Parameters:

paramStr - a PROJ.4 projection parameter string

Returns:

the specified CoordinateReferenceSystem

Throws:

IOException - if there was an issue in reading EPSG file

readEpsgFromParameters

public String readEpsgFromParameters(String[] params)
                              throws IOException

Finds a EPSG Code defined by an array of PROJ.4 projection parameters. PROJ.4 parameters are generally of the form "+name=value".

Parameters:

params - an array of PROJ.4 projection parameters

Returns:

s String EPSG code

Throws:

IOException - if there was an issue in reading EPSG file

splitParameters

private static String[] splitParameters(String paramStr)