Class WKTReader
Geometry
.
WKTReader
supports
extracting Geometry
objects from either Reader
s or
String
s. This allows it to function as a parser to read Geometry
objects from text blocks embedded in other data formats (e.g. XML).
A WKTReader
is parameterized by a GeometryFactory
,
to allow it to create Geometry
objects of the appropriate
implementation. In particular, the GeometryFactory
determines the PrecisionModel
and SRID
that is
used.
The WKTReader
converts all input numbers to the precise
internal representation.
Notes:
- Keywords are case-insensitive.
- The reader supports non-standard "LINEARRING" tags.
- The reader uses Double.parseDouble to perform the conversion of ASCII numbers to floating point. This means it supports the Java syntax for floating point literals (including scientific notation).
Syntax
The following syntax specification describes the version of Well-Known Text supported by JTS. (The specification uses a syntax language similar to that used in the C and Java language specifications.)As of version 1.15, JTS can read (but not write) WKT Strings including Z, M or ZM in the name of the geometry type (ex. POINT Z, LINESTRINGZM). Note that it only makes the reader more flexible, but JTS could already read 3D coordinates from WKT String and still can't read 4D coordinates.
WKTGeometry: one of WKTPoint WKTLineString WKTLinearRing WKTPolygon WKTMultiPoint WKTMultiLineString WKTMultiPolygon WKTGeometryCollection WKTPoint: POINT[Dimension] ( Coordinate ) WKTLineString: LINESTRING[Dimension] CoordinateSequence WKTLinearRing: LINEARRING[Dimension] CoordinateSequence WKTPolygon: POLYGON[Dimension] CoordinateSequenceList WKTMultiPoint: MULTIPOINT[Dimension] CoordinateSingletonList WKTMultiLineString: MULTILINESTRING[Dimension] CoordinateSequenceList WKTMultiPolygon: MULTIPOLYGON[Dimension] ( CoordinateSequenceList { , CoordinateSequenceList } ) WKTGeometryCollection: GEOMETRYCOLLECTION[Dimension] ( WKTGeometry { , WKTGeometry } ) CoordinateSingletonList: ( CoordinateSingleton { , CoordinateSingleton } ) | EMPTY CoordinateSingleton: ( Coordinate ) | EMPTY CoordinateSequenceList: ( CoordinateSequence { , CoordinateSequence } ) | EMPTY CoordinateSequence: ( Coordinate { , Coordinate } ) | EMPTY Coordinate: Number Number Numberopt Number: A Java-style floating-point number (including NaN, with arbitrary case) Dimension: Z| Z|M| M|ZM| ZM
- Version:
- 1.7
- See Also:
-
Field Summary
FieldsModifier and TypeFieldDescriptionprivate static final boolean
private static final String
private static final String
private GeometryFactory
private static final String
private boolean
private static final String
private PrecisionModel
private static final String
private StreamTokenizer
private boolean
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Constructor Summary
ConstructorsConstructorDescriptionCreates a reader that creates objects using the defaultGeometryFactory
.WKTReader
(GeometryFactory geometryFactory) Creates a reader that creates objects using the givenGeometryFactory
. -
Method Summary
Modifier and TypeMethodDescriptionprivate Coordinate[]
Returns the next array ofCoordinate
s in the stream.private Coordinate[]
private String
Returns the next R_PAREN in the stream.private String
Returns the next R_PAREN or COMMA in the stream.private String
Returns the next EMPTY or L_PAREN in the stream as uppercase text.private double
Parses the next number in the stream.private String
Returns the next word in the stream.private Coordinate
private boolean
private String
Returns the next word in the stream.private void
parseErrorExpected
(String expected) Throws a formatted ParseException reporting that the current token was unexpected.private void
parseErrorWithLine
(String msg) private GeometryCollection
Creates aGeometryCollection
using the next token in the stream.private Geometry
Creates aGeometry
using the next token in the stream.private LinearRing
Creates aLinearRing
using the next token in the stream.private LineString
Creates aLineString
using the next token in the stream.private MultiLineString
Creates aMultiLineString
using the next token in the stream.private MultiPoint
Creates aMultiPoint
using the next tokens in the stream.private MultiPolygon
Creates aMultiPolygon
using the next token in the stream.private Point
Creates aPoint
using the next token in the stream.private Polygon
Creates aPolygon
using the next token in the stream.private String
Gets a description of the current tokenprivate Point[]
toPoints
(Coordinate[] coordinates) Creates an array ofPoint
s having the givenCoordinate
s.
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Field Details
-
EMPTY
- See Also:
-
COMMA
- See Also:
-
L_PAREN
- See Also:
-
R_PAREN
- See Also:
-
NAN_SYMBOL
- See Also:
-
geometryFactory
-
precisionModel
-
tokenizer
-
z
private boolean z -
m
private boolean m -
ALLOW_OLD_JTS_MULTIPOINT_SYNTAX
private static final boolean ALLOW_OLD_JTS_MULTIPOINT_SYNTAX- See Also:
-
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Constructor Details
-
WKTReader
public WKTReader()Creates a reader that creates objects using the defaultGeometryFactory
. -
WKTReader
Creates a reader that creates objects using the givenGeometryFactory
.- Parameters:
geometryFactory
- the factory used to createGeometry
s.
-
-
Method Details
-
read
- Parameters:
wellKnownText
- one or more <Geometry Tagged Text> strings (see the OpenGIS Simple Features Specification) separated by whitespace- Returns:
- a
Geometry
specified bywellKnownText
- Throws:
ParseException
- if a parsing problem occurs
-
read
- Parameters:
reader
- a Reader which will return a <Geometry Tagged Text> string (see the OpenGIS Simple Features Specification)- Returns:
- a
Geometry
read fromreader
- Throws:
ParseException
- if a parsing problem occurs
-
getCoordinates
Returns the next array ofCoordinate
s in the stream.- Parameters:
tokenizer
- tokenizer over a stream of text in Well-known Text format. The next element returned by the stream should be L_PAREN (the beginning of "(x1 y1, x2 y2, ..., xn yn)") or EMPTY.- Returns:
- the next array of
Coordinate
s in the stream, or an empty array if EMPTY is the next element returned by the stream. - Throws:
IOException
- if an I/O error occursParseException
- if an unexpected token was encountered
-
getCoordinatesNoLeftParen
- Throws:
IOException
ParseException
-
getPreciseCoordinate
- Throws:
IOException
ParseException
-
isNumberNext
- Throws:
IOException
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getNextNumber
Parses the next number in the stream. Numbers with exponents are handled. NaN values are handled correctly, and the case of the "NaN" symbol is not significant.- Parameters:
tokenizer
- tokenizer over a stream of text in Well-known Text format. The next token must be a number.- Returns:
- the next number in the stream
- Throws:
ParseException
- if the next token is not a valid numberIOException
- if an I/O error occurs
-
getNextEmptyOrOpener
Returns the next EMPTY or L_PAREN in the stream as uppercase text.- Parameters:
tokenizer
- tokenizer over a stream of text in Well-known Text format. The next token must be EMPTY or L_PAREN.- Returns:
- the next EMPTY or L_PAREN in the stream as uppercase text.
- Throws:
ParseException
- if the next token is not EMPTY or L_PARENIOException
- if an I/O error occurs
-
getNextCloserOrComma
Returns the next R_PAREN or COMMA in the stream.- Parameters:
tokenizer
- tokenizer over a stream of text in Well-known Text format. The next token must be R_PAREN or COMMA.- Returns:
- the next R_PAREN or COMMA in the stream
- Throws:
ParseException
- if the next token is not R_PAREN or COMMAIOException
- if an I/O error occurs
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getNextCloser
Returns the next R_PAREN in the stream.- Parameters:
tokenizer
- tokenizer over a stream of text in Well-known Text format. The next token must be R_PAREN.- Returns:
- the next R_PAREN in the stream
- Throws:
ParseException
- if the next token is not R_PARENIOException
- if an I/O error occurs
-
getNextWord
Returns the next word in the stream.- Parameters:
tokenizer
- tokenizer over a stream of text in Well-known Text format. The next token must be a word.- Returns:
- the next word in the stream as uppercase text
- Throws:
ParseException
- if the next token is not a wordIOException
- if an I/O error occurs
-
lookaheadWord
Returns the next word in the stream.- Parameters:
tokenizer
- tokenizer over a stream of text in Well-known Text format. The next token must be a word.- Returns:
- the next word in the stream as uppercase text
- Throws:
ParseException
- if the next token is not a wordIOException
- if an I/O error occurs
-
parseErrorExpected
Throws a formatted ParseException reporting that the current token was unexpected.- Parameters:
expected
- a description of what was expected- Throws:
ParseException
AssertionFailedException
- if an invalid token is encountered
-
parseErrorWithLine
- Throws:
ParseException
-
tokenString
Gets a description of the current token- Returns:
- a description of the current token
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readGeometryTaggedText
Creates aGeometry
using the next token in the stream.- Parameters:
tokenizer
- tokenizer over a stream of text in Well-known Text format. The next tokens must form a <Geometry Tagged Text>.- Returns:
- a
Geometry
specified by the next token in the stream - Throws:
ParseException
- if the coordinates used to create aPolygon
shell and holes do not form closed linestrings, or if an unexpected token was encounteredIOException
- if an I/O error occurs
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readPointText
Creates aPoint
using the next token in the stream.- Parameters:
tokenizer
- tokenizer over a stream of text in Well-known Text format. The next tokens must form a <Point Text>.- Returns:
- a
Point
specified by the next token in the stream - Throws:
IOException
- if an I/O error occursParseException
- if an unexpected token was encountered
-
readLineStringText
Creates aLineString
using the next token in the stream.- Parameters:
tokenizer
- tokenizer over a stream of text in Well-known Text format. The next tokens must form a <LineString Text>.- Returns:
- a
LineString
specified by the next token in the stream - Throws:
IOException
- if an I/O error occursParseException
- if an unexpected token was encountered
-
readLinearRingText
Creates aLinearRing
using the next token in the stream.- Parameters:
tokenizer
- tokenizer over a stream of text in Well-known Text format. The next tokens must form a <LineString Text>.- Returns:
- a
LinearRing
specified by the next token in the stream - Throws:
IOException
- if an I/O error occursParseException
- if the coordinates used to create theLinearRing
do not form a closed linestring, or if an unexpected token was encountered
-
readMultiPointText
Creates aMultiPoint
using the next tokens in the stream.- Parameters:
tokenizer
- tokenizer over a stream of text in Well-known Text format. The next tokens must form a <MultiPoint Text>.- Returns:
- a
MultiPoint
specified by the next token in the stream - Throws:
IOException
- if an I/O error occursParseException
- if an unexpected token was encountered
-
toPoints
Creates an array ofPoint
s having the givenCoordinate
s.- Parameters:
coordinates
- theCoordinate
s with which to create thePoint
s- Returns:
Point
s created using thisWKTReader
sGeometryFactory
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readPolygonText
Creates aPolygon
using the next token in the stream.- Parameters:
tokenizer
- tokenizer over a stream of text in Well-known Text format. The next tokens must form a <Polygon Text>.- Returns:
- a
Polygon
specified by the next token in the stream - Throws:
ParseException
- if the coordinates used to create thePolygon
shell and holes do not form closed linestrings, or if an unexpected token was encountered.IOException
- if an I/O error occurs
-
readMultiLineStringText
Creates aMultiLineString
using the next token in the stream.- Parameters:
tokenizer
- tokenizer over a stream of text in Well-known Text format. The next tokens must form a <MultiLineString Text>.- Returns:
- a
MultiLineString
specified by the next token in the stream - Throws:
IOException
- if an I/O error occursParseException
- if an unexpected token was encountered
-
readMultiPolygonText
Creates aMultiPolygon
using the next token in the stream.- Parameters:
tokenizer
- tokenizer over a stream of text in Well-known Text format. The next tokens must form a <MultiPolygon Text>.- Returns:
- a
MultiPolygon
specified by the next token in the stream, or if if the coordinates used to create thePolygon
shells and holes do not form closed linestrings. - Throws:
IOException
- if an I/O error occursParseException
- if an unexpected token was encountered
-
readGeometryCollectionText
Creates aGeometryCollection
using the next token in the stream.- Parameters:
tokenizer
- tokenizer over a stream of text in Well-known Text format. The next tokens must form a <GeometryCollection Text>.- Returns:
- a
GeometryCollection
specified by the next token in the stream - Throws:
ParseException
- if the coordinates used to create aPolygon
shell and holes do not form closed linestrings, or if an unexpected token was encounteredIOException
- if an I/O error occurs
-