Module org.apache.sis.referencing
Package org.apache.sis.io.wkt

Class WKTFormat

Object
Format
CompoundFormat<Object>
WKTFormat
All Implemented Interfaces:
Serializable, Cloneable, Localized
public class WKTFormat extends CompoundFormat<Object>
Parser and formatter for Well Known Text (WKT) strings. This format handles a pair of Parser and Formatter, used by the parse(…) and format(…) methods respectively. WKTFormat objects allow the following configuration:

String expansion

Because the strings to be parsed by this class are long and tend to contain repetitive substrings, WKTFormat provides a mechanism for performing string substitutions before the parsing take place. Long strings can be assigned short names by calls to the add­Fragment(String, String) method. After fragments have been added, any call to a parsing method will replace all occurrences (except in quoted text) of tokens like $foo by the WKT fragment named "foo".

Example

In the example below, the $WGS84 substring which appear in the argument given to the parse­Object(…) method will be expanded into the full Geodetic­CRS[“WGS84”, …] string before the parsing proceed.
add­Fragment("deg", "Angle­Unit[“degree”, 0.0174532925199433]");
add­Fragment("lat", "Axis[“Latitude”, NORTH, $deg]");
add­Fragment("lon", "Axis[“Longitude”, EAST, $deg]");
add­Fragment("My­Base­CRS", "Geodetic­CRS[“WGS84”, Datum[ …etc… ], CS[ …etc… ], $lat, $lon]");
Object crs = parse­Object("Projected­CRS[“Mercator_1SP”, $My­Base­CRS, …etc… ]");
Note that the parsing of WKT fragment does not always produce the same object. In particular, the default linear and angular units depend on the context in which the WKT fragment appears.

Limitations

  • The WKT format is not lossless! Objects formatted by WKTFormat are not guaranteed to be identical after parsing. Some metadata may be lost or altered, but the coordinate operations between two CRS should produce the same numerical results provided that the two CRS were formatted independently (do not rely on General­Derived­CRS​.get­Conversion­From­Base() for instance).
  • Instances of this class are not synchronized for multi-threading. It is recommended to create separated format instances for each thread. If multiple threads access a WKTFormat concurrently, it must be synchronized externally.
  • Serialized objects of this class are not guaranteed to be compatible with future Apache SIS releases. Serialization support is appropriate for short term storage or RMI between applications running the same version of Apache SIS.
Since:
0.4
See Also:

  • Field Details

  • Constructor Details

    • WKTFormat

      public WKTFormat(Locale locale, TimeZone timezone)
      Creates a format for the given locale and timezone. The given locale will be used for International­String localization; this is not the locale for number format.
      Parameters:
      locale - the locale for the new Format, or null for Locale​.ROOT.
      timezone - the timezone, or null for UTC.

  • Method Details

    • getLocale

      public Locale getLocale(Locale.Category category)
      Returns the locale for the given category. This method implements the following mapping:
      Overrides:
      get­Locale in class Compound­Format<Object>
      Parameters:
      category - the category for which a locale is desired.
      Returns:
      the locale for the given category (never null).

    • getSymbols

      public Symbols getSymbols()
      Returns the symbols used for parsing and formatting WKT. This method returns an unmodifiable instance. Modifications, if desired, should be applied on a clone of the returned object.
      Returns:
      the current set of symbols used for parsing and formatting WKT.

    • setSymbols

      public void setSymbols(Symbols symbols)
      Sets the symbols used for parsing and formatting WKT.
      Parameters:
      symbols - the new set of symbols to use for parsing and formatting WKT.

    • getTransliterator

      public Transliterator getTransliterator()
      Returns a mapper between Java character sequences and the characters to write in WKT. The intent is to specify how to write characters that are not allowed in WKT strings according ISO 19162 specification. Return values can be:
      Returns:
      the mapper between Java character sequences and the characters to write in WKT.
      Since:
      0.6

    • setTransliterator

      public void setTransliterator(Transliterator transliterator)
      Sets the mapper between Java character sequences and the characters to write in WKT.

      If this method is never invoked, or if this method is invoked with a null value, then the default mapper is Transliterator​.DEFAULT except for WKT formatted according the internal convention.

      Parameters:
      transliterator - the new mapper to use, or null for restoring the default value.
      Since:
      0.6

    • getKeywordCase

      public KeywordCase getKeywordCase()
      Returns whether WKT keywords should be written with upper cases or camel cases.
      Returns:
      the case to use for formatting keywords.

    • setKeywordCase

      public void setKeywordCase(KeywordCase keywordCase)
      Sets whether WKT keywords should be written with upper cases or camel cases.
      Parameters:
      keyword­Case - the case to use for formatting keywords.

    • getKeywordStyle

      public KeywordStyle getKeywordStyle()
      Returns whether to use short or long WKT keywords.
      Returns:
      the style used for formatting keywords.
      Since:
      0.6

    • setKeywordStyle

      public void setKeywordStyle(KeywordStyle keywordStyle)
      Sets whether to use short or long WKT keywords.
      Parameters:
      keyword­Style - the style to use for formatting keywords.
      Since:
      0.6

    • getColors

      public Colors getColors()
      Returns the colors to use for syntax coloring, or null if none. This method returns an unmodifiable instance. Modifications, if desired, should be applied on a clone of the returned object. By default there is no syntax coloring.
      Returns:
      the colors for syntax coloring, or null if none.

    • setColors

      public void setColors(Colors colors)
      Sets the colors to use for syntax coloring. This property applies only when formatting text.

      Newly created WKTFormats have no syntax coloring. If a non-null argument like Colors​.DEFAULT is given to this method, then the format(…) method tries to highlight most of the elements that are relevant to Utilities​.equals­Ignore­Metadata(Object, Object).

      Parameters:
      colors - the colors for syntax coloring, or null if none.

    • getConvention

      public Convention getConvention()
      Returns the convention for parsing and formatting WKT elements. The default value is Convention​.WKT2.
      Returns:
      the convention to use for formatting WKT elements (never null).

    • setConvention

      public void setConvention(Convention convention)
      Sets the convention for parsing and formatting WKT elements.
      Parameters:
      convention - the new convention to use for parsing and formatting WKT elements.

    • getNameAuthority

      public Citation getNameAuthority()
      Returns the preferred authority to look for when fetching identified object names and identifiers. The difference between various authorities are most easily seen in projection and parameter names. If no authority has been explicitly set, then this method returns the default authority for the current convention.

      Example

      The following table shows the names given by various organizations or projects for the same projection:
      Projection name examples
      Authority Projection name
      EPSG Mercator (variant A)
      OGC Mercator_1SP
      GEOTIFF CT_Mercator
      Returns:
      the organization, standard or project to look for when fetching projection and parameter names.
      See Also:

    • setNameAuthority

      public void setNameAuthority(Citation authority)
      Sets the preferred authority for choosing the projection and parameter names. If non-null, the given priority will have precedence over the authority usually associated to the convention. A null value restore the default behavior.
      Parameters:
      authority - the new authority, or null for inferring it from the convention.
      See Also:

    • getIndentation

      public int getIndentation()
      Returns the current indentation to be used for formatting objects. The -1 value means that the whole WKT is to be formatted on a single line.
      Returns:
      the current indentation.

    • setIndentation

      public void setIndentation(int indentation)
      Sets a new indentation to be used for formatting objects. The -1 value means that the whole WKT is to be formatted on a single line.
      Parameters:
      indentation - the new indentation to use.
      See Also:

    • getMaximumListElements

      public int getMaximumListElements()
      Returns the maximum number of elements to show in lists of values. If a list length is greater than this limit, then only the first and last elements will be shown together with a message saying that some elements were omitted. This limit is useful in particular with Math­Transform parameter values of double[] type, since those parameters may be large interpolation tables.
      Returns:
      the current lists size limit, or Integer​.MAX_VALUE if unlimited.
      Since:
      1.0

    • setMaximumListElements

      public void setMaximumListElements(int limit)
      Sets a new limit for the number of elements to show in lists. If this method is never invoked, then the default is unlimited.
      Parameters:
      limit - the new lists size limit, or Integer​.MAX_VALUE if unlimited.
      Since:
      1.0

    • getFactory

      public <T extends Factory> T getFactory(Class<T> type)
      Returns one of the factories used by this WKTFormat for parsing WKT. The given type argument can be one of the following values:
      Type Parameters:
      T - the compile-time type of the type argument.
      Parameters:
      type - the factory type.
      Returns:
      the factory used by this WKTFormat for the given type.
      Throws:
      Illegal­Argument­Exception - if the type argument is not one of the valid values.

    • setFactory

      public <T extends Factory> void setFactory(Class<T> type, T factory)
      Sets one of the factories to be used by this WKTFormat for parsing WKT. The given type argument can be one of the following values:

      Limitation

      The current implementation does not serialize the given factories, because they are usually not Serializable. The factories used by WKTFormat instances after deserialization are the default ones.
      Type Parameters:
      T - the compile-time type of the type argument.
      Parameters:
      type - the factory type.
      factory - the factory to be used by this WKTFormat for the given type.
      Throws:
      Illegal­Argument­Exception - if the type argument is not one of the valid values.

    • getValueType

      public final Class<Object> getValueType()
      Returns the type of objects formatted by this class. This method has to return Object​.class since it is the only common parent to all object types accepted by this formatter.
      Specified by:
      get­Value­Type in class Compound­Format<Object>
      Returns:
      Object​.class

    • getFragmentNames

      public Set<String> getFragmentNames()
      Returns the name of all WKT fragments known to this WKTFormat. The returned collection is initially empty. WKT fragments can be added by call to add­Fragment(String, String).

      The returned collection is modifiable. In particular, a call to Set​.clear() removes all fragments from this WKTFormat.

      Returns:
      the name of all fragments known to this WKTFormat.

    • addFragment

      public void addFragment(String name, String wkt) throws IllegalArgumentException, ParseException
      Adds a fragment of Well Know Text (WKT). The wkt argument given to this method can contains itself other fragments specified in some previous calls to this method.

      Example

      If the following method is invoked: 
      addFragment("MyEllipsoid", "Ellipsoid[“Bessel 1841”, 6377397.155, 299.1528128, ID[“EPSG”,“7004”]]");
      Then other WKT strings parsed by this WKTFormat instance can refer to the above fragment as below (WKT after the ellipsoid omitted for brevity): 
      Object crs = parseObject("GeodeticCRS[“Tokyo”, Datum[“Tokyo”, $MyEllipsoid], …]");
      For removing a fragment, use get­Fragment­Names().remove(name).
      Parameters:
      name - the name to assign to the WKT fragment (case-sensitive). Must be a valid Unicode identifier.
      wkt - the Well Know Text (WKT) fragment represented by the given identifier.
      Throws:
      Illegal­Argument­Exception - if the given name is not a valid Unicode identifier or if a fragment is already associated to that name.
      Parse­Exception - if an error occurred while parsing the given WKT.

    • parse

      public Object parse(CharSequence wkt, ParsePosition pos) throws ParseException
      Creates an object from the given character sequence. The parsing begins at the index given by the pos argument. After successful parsing, Parse­Position​.get­Index() gives the position after the last parsed character. In case of error, Parse­Exception​.get­Error­Offset() gives the position of the first illegal character.
      Specified by:
      parse in class Compound­Format<Object>
      Parameters:
      wkt - the character sequence for the object to parse.
      pos - index of the first character to parse (on input) or after last parsed character (on output).
      Returns:
      the parsed object (never null).
      Throws:
      Parse­Exception - if an error occurred while parsing the WKT.

    • format

      public void format(Object object, Appendable toAppendTo) throws IOException
      Formats the specified object as a Well Know Text. The formatter accepts at least the following types: Formattable­Object, Identified­Object, Math­Transform, Geographic­Bounding­Box, Vertical­Extent, Temporal­Extent, Envelope, Position and Unit.
      Specified by:
      format in class Compound­Format<Object>
      Parameters:
      object - the object to format.
      to­Append­To - where the text is to be appended.
      Throws:
      IOException - if an error occurred while writing to to­Append­To.
      See Also:

    • createFormat

      protected Format createFormat(Class<?> valueType)
      Creates a new format to use for parsing and formatting values of the given type. This method is invoked the first time that a format is needed for the given type. The value­Type can be any types declared in the parent class.
      Overrides:
      create­Format in class Compound­Format<Object>
      Parameters:
      value­Type - the base type of values to parse or format.
      Returns:
      the format to use for parsing of formatting values of the given type, or null if none.

    • getWarnings

      public Warnings getWarnings()
      If warnings occurred during the last WKT parsing or formatting, returns the warnings. Otherwise returns null. The warnings are cleared every time a new object is parsed or formatted.
      Returns:
      the warnings of the last parsing of formatting operation, or null if none.
      Since:
      0.6

    • clone

      public WKTFormat clone()
      Returns a clone of this format. The clone has the same configuration (including any added fragments), except the warnings.
      Overrides:
      clone in class Compound­Format<Object>
      Returns:
      a clone of this format.