Package uk.ac.starlink.table

Class DefaultValueInfo

java.lang.Object
uk.ac.starlink.table.DefaultValueInfo
All Implemented Interfaces:
ValueInfo
Direct Known Subclasses:
ColumnInfo
public class DefaultValueInfo extends Object implements ValueInfo
Default implementation of the ValueInfo interface. Additionally provides mutator methods for the accessors defined in ValueInfo.
Author:
Mark Taylor (Starlink)

  • Constructor Summary

    Constructors
    Constructor
    Description
    DefaultValueInfo()
    Constructs a new generic DefaultValueInfo object without a name.
    DefaultValueInfo(String name)
    Constructs a new generic DefaultValueInfo object with a given name.
    DefaultValueInfo(String name, Class<?> contentClass)
    Constructs a new DefaultValueInfo object with a given name and class.
    DefaultValueInfo(String name, Class<?> contentClass, String description)
    Constructs a new DefaultValueInfo object with a given name, class and description.
    DefaultValueInfo(ValueInfo base)
    Constructs a DefaultValueInfo object which is a copy of an existing one.

  • Method Summary

    Modifier and Type
    Method
    Description
    static String
    formatClass(Class<?> clazz)
    Returns a human-friendly string indicating the class and shape of a given class object.
    static String
    formatShape(int[] shape)
    Returns a string representing the shape of this object, if it is array-like.
    String
    formatValue(Object value, int maxLength)
    Returns a string representation of a given value described by this ValueInfo.
    static ValueInfo
    generalise(ValueInfo vi1, ValueInfo vi2)
    Returns a ValueInfo object which is sufficiently general to cover every object described by either of two given ValueInfo objects.
    List<DescribedValue>
    getAuxData()
    Returns a list of auxiliary metadata objects pertaining to this column.
    Class<?>
    getContentClass()
    Returns the java class of the values described by this object.
    String
    getDescription()
    Returns a description of the values described by this object.
    DomainMapper[]
    getDomainMappers()
    Returns an array of objects which may be able to convert from the values described by this info to a particular target value domain.
    int
    getElementSize()
    May indicate the size of a value element stored as the value of this info.
    String
    getName()
    Returns the name of this object.
    int[]
    getShape()
    Returns the shape associated with array value types.
    String
    getUCD()
    Returns the Unified Column Descriptor string applying to the values described by this object.
    String
    getUnitString()
    Returns a string representing the units of the values described by this object.
    String
    getUtype()
    Returns the Utype string applying to the values described by this object.
    String
    getXtype()
    Returns the Xtype string applying to the values described by this object.
    boolean
    isArray()
    Indicates whether the values described by this object are java arrays.
    boolean
    isNullable()
    Indicates whether values returned described by this object may have the value null.
    void
    setAuxData(List<DescribedValue> auxData)
    Sets the list of auxiliary metadata items for this column.
    void
    setContentClass(Class<?> contentClass)
    Sets the java class of objects contained in this column.
    void
    setDescription(String description)
    Sets a textual description of the values described by this object.
    void
    setDomainMappers(DomainMapper[] domainMappers)
    Sets the domain mappers known for this object.
    void
    setElementSize(int size)
    Sets the element size of values described by this object.
    void
    setName(String name)
    Sets the name for this object.
    void
    setNullable(boolean isNullable)
    Sets whether values described by this object may have the value null.
    void
    setShape(int[] shape)
    Sets the shape of values described by this object.
    void
    setUCD(String ucd)
    Sets the Unified Content Descriptor string applying to values described by this object.
    void
    setUnitString(String unitString)
    Sets the string representing the units for the values described by this object.
    void
    setUtype(String utype)
    Sets the Utype string applying to values described by this object.
    void
    setXtype(String xtype)
    Sets the Xtype string applying to values described by this object.
    String
    toString()
    Returns a string representation of this object.
    static int[]
    unformatShape(String txt)
    Takes a stringified version of the shape and turns it into an array.
    Object
    unformatString(String rep)
    Returns an object of the sort described by this ValueInfo represented by the given string rep.

    Methods inherited from class java.lang.Object

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

    Methods inherited from interface uk.ac.starlink.table.ValueInfo

    getAuxDatumByName, setAuxDatum

  • Constructor Details

    • DefaultValueInfo

      public DefaultValueInfo()
      Constructs a new generic DefaultValueInfo object without a name.

    • DefaultValueInfo

      public DefaultValueInfo(String name)
      Constructs a new generic DefaultValueInfo object with a given name.
      Parameters:
      name - the name applying to described values

    • DefaultValueInfo

      public DefaultValueInfo(String name, Class<?> contentClass)
      Constructs a new DefaultValueInfo object with a given name and class.
      Parameters:
      name - the name applying to described values
      contentClass - the class of which described values should be instances

    • DefaultValueInfo

      public DefaultValueInfo(String name, Class<?> contentClass, String description)
      Constructs a new DefaultValueInfo object with a given name, class and description.
      Parameters:
      name - the name applying to described values
      contentClass - the class of which described values should be instances
      description - a textual description of the described values

    • DefaultValueInfo

      public DefaultValueInfo(ValueInfo base)
      Constructs a DefaultValueInfo object which is a copy of an existing one. The fields of the new object are copies (where possible not references to) those of the base one.
      Parameters:
      base - the object to copy

  • Method Details

    • setName

      public void setName(String name)
      Sets the name for this object.
      Parameters:
      name - the name

    • getName

      public String getName()
      Description copied from interface: ValueInfo
      Returns the name of this object.
      Specified by:
      getName in interface ValueInfo
      Returns:
      the name

    • setUnitString

      public void setUnitString(String unitString)
      Sets the string representing the units for the values described by this object.
      Parameters:
      unitString - a string giving the units, or null if units are unknown

    • getUnitString

      public String getUnitString()
      Description copied from interface: ValueInfo
      Returns a string representing the units of the values described by this object. The syntax and conventions should ideally match those adopted by VOTable, as defined by CDS.
      Specified by:
      getUnitString in interface ValueInfo
      Returns:
      a string giving the units, or null if units are unknown
      See Also:

    • setUCD

      public void setUCD(String ucd)
      Sets the Unified Content Descriptor string applying to values described by this object.
      Parameters:
      ucd - the UCD, or null if none is known

    • getUCD

      public String getUCD()
      Description copied from interface: ValueInfo
      Returns the Unified Column Descriptor string applying to the values described by this object.
      Specified by:
      getUCD in interface ValueInfo
      Returns:
      the UCD, or null if none is known
      See Also:

    • setUtype

      public void setUtype(String utype)
      Sets the Utype string applying to values described by this object.
      Parameters:
      utype - the Utype, or null if none is known

    • getUtype

      public String getUtype()
      Description copied from interface: ValueInfo
      Returns the Utype string applying to the values described by this object. Utype is a string which references a data model. It is used pervasively within IVOA standards; probably an official IVOA definition of Utype syntax and semantics will arise one day.
      Specified by:
      getUtype in interface ValueInfo
      Returns:
      the Utype, or null if none is known

    • setXtype

      public void setXtype(String xtype)
      Sets the Xtype string applying to values described by this object.
      Parameters:
      xtype - the Xtype, or null if none is known

    • getXtype

      public String getXtype()
      Description copied from interface: ValueInfo
      Returns the Xtype string applying to the values described by this object. The Xtype string is the 'extended type' information characterising the data type beyond the primitive data type. It is used within IVOA standards, and a number of standard values are defined within the DALI standard.
      Specified by:
      getXtype in interface ValueInfo
      Returns:
      the Xtype, or null if none is known

    • setDescription

      public void setDescription(String description)
      Sets a textual description of the values described by this object.
      Parameters:
      description - a texttual description of this column, or the empty string "" if there is nothing to be said

    • getDescription

      public String getDescription()
      Description copied from interface: ValueInfo
      Returns a description of the values described by this object. It may contain a short or long textual description of the kind of information represented by the value.
      Specified by:
      getDescription in interface ValueInfo
      Returns:
      a textual description, or the empty string "" if there is nothing to be said

    • getContentClass

      public Class<?> getContentClass()
      Description copied from interface: ValueInfo
      Returns the java class of the values described by this object. The intention is that any Object described by this ValueInfo will be an instance of the returned class or one of its subclasses. Note therefore that it must not return one of the primitive class objects (int.class et al.); the appropriate wrapper classes must be used instead (Integer.class etc).

      The class returned should not under normal circumstances be an array of arrays; to express multidimensionality of arrays you should store an array of non-array objects or of primitives and provide shape information via the getShape method. There is nothing to stop you describing arrays of arrays with a ValueInfo, but some other elements of the tables infrastructure and applications may work on the assumption that such objects are not present.

      Note that to store sets of more than 231 items it will be necessary to use some custom object, since java arrays are indexed by type int.

      Specified by:
      getContentClass in interface ValueInfo
      Returns:
      the java class

    • setContentClass

      public void setContentClass(Class<?> contentClass)
      Sets the java class of objects contained in this column.
      Parameters:
      contentClass - the class of items in this column
      Throws:
      IllegalArgumentException - if contentClass is primitive

    • isArray

      public boolean isArray()
      Description copied from interface: ValueInfo
      Indicates whether the values described by this object are java arrays. This convenience method should return the same as 
           getContentClass().getComponentType()!=null
      Specified by:
      isArray in interface ValueInfo
      Returns:
      true iff the values described by this object are java arrays

    • getShape

      public int[] getShape()
      Description copied from interface: ValueInfo
      Returns the shape associated with array value types. If the class returned by ValueInfo.getContentClass() is a java array type, the return from this method may contain information about the shape of the rectangular array which this represents. The dimensions of the array are given in the elements of the return value of this method, fastest varying first. All elements of the array should be positive, except that the last (slowest varying) element may be <=0 (conventionally -1) to indicate that the number of (shape.length-1)-dimensional slices contained in the value is not known. If nothing is known about the shape of the array values, then a 1-element array whose only element is <=0 should be returned.

      If getContentClass does not give an array type (hence isArray returns false) the return value for this method is undefined (but should probably be null).

      Specified by:
      getShape in interface ValueInfo
      Returns:
      the shape of the array value

    • setShape

      public void setShape(int[] shape)
      Sets the shape of values described by this object.
      Parameters:
      shape - the shape
      Throws:
      IllegalArgumentException - if shape has elements apart from the last one which are <=0

    • getElementSize

      public int getElementSize()
      Description copied from interface: ValueInfo
      May indicate the size of a value element stored as the value of this info. The total size of the value will in this case be the return value of this method multiplied by the number of elements, as indicated by ValueInfo.getShape() (or by 1, if getShape is null).

      The exact meaning of the value returned is dependent on this ValueInfo. This method was introduced to return the maximum number of characters in a String-class ValueInfo; this information is necessary for writing out to certain formats (FITS). Other ValueInfo types however may use it for their own purposes.

      ValueInfo instances which decline to supply this information should return -1 from this method.

      Specified by:
      getElementSize in interface ValueInfo
      Returns:
      notional size of each element an array of values described by this info

    • setElementSize

      public void setElementSize(int size)
      Sets the element size of values described by this object.
      Parameters:
      size - the element size

    • isNullable

      public boolean isNullable()
      Description copied from interface: ValueInfo
      Indicates whether values returned described by this object may have the value null. In general this should return true, which implies no assertion about the return values (they may or may not be null). But if the values are known never to be null, it may return false.
      Specified by:
      isNullable in interface ValueInfo
      Returns:
      false if values are guaranteed non-null

    • setNullable

      public void setNullable(boolean isNullable)
      Sets whether values described by this object may have the value null. By setting this to false you assert that no null objects will be returned from this column.
      Parameters:
      isNullable - false if objects in this column are guaranteed non-null

    • getDomainMappers

      public DomainMapper[] getDomainMappers()
      Description copied from interface: ValueInfo
      Returns an array of objects which may be able to convert from the values described by this info to a particular target value domain. This can used for non-obvious representations of certain coordinates such as time and angular position. In most cases the returned array will be empty, since the target domain is obvious (e.g. numeric values). In the (unusual) case that the returned array contains multiple entries, it should have no more than one for any given target domain, and the first entry may be considered "primary" in some sense. Absence of a mapper for a given target domain does not necessarily indicate that the described values cannot be used in that domain.
      Specified by:
      getDomainMappers in interface ValueInfo
      Returns:
      array of domain mappers for the values described by this info

    • setDomainMappers

      public void setDomainMappers(DomainMapper[] domainMappers)
      Sets the domain mappers known for this object.
      Parameters:
      domainMappers - new domain mapper array

    • getAuxData

      public List<DescribedValue> getAuxData()
      Returns a list of auxiliary metadata objects pertaining to this column. The returned value may, if mutable, be modified to change the aux data of this object.
      Specified by:
      getAuxData in interface ValueInfo
      Returns:
      a List of DescribedValue items

    • setAuxData

      public void setAuxData(List<DescribedValue> auxData)
      Sets the list of auxiliary metadata items for this column.
      Parameters:
      auxData - a list of DescribedValue objects

    • generalise

      public static ValueInfo generalise(ValueInfo vi1, ValueInfo vi2)
      Returns a ValueInfo object which is sufficiently general to cover every object described by either of two given ValueInfo objects. For most of the info attributes this entails setting to null any attribute which is not the same for both, though for contentClass it involves finding the most specific common ancestor class.
      Parameters:
      vi1 - one ValueInfo object
      vi2 - the other ValueInfo object
      Returns:
      a generalised ValueInfo object

    • formatValue

      public String formatValue(Object value, int maxLength)
      Description copied from interface: ValueInfo
      Returns a string representation of a given value described by this ValueInfo. The returned string should be no longer than a given maximum length.
      Specified by:
      formatValue in interface ValueInfo
      Parameters:
      value - the value to represent
      maxLength - the maximum number of characters in the returned string

    • formatClass

      public static String formatClass(Class<?> clazz)
      Returns a human-friendly string indicating the class and shape of a given class object. This will read something like "Integer" or "byte[][]" or "uk.ac.starlink.FrameSet".
      Parameters:
      clazz - the class
      Returns:
      a string showing the class and shape of clazz

    • formatShape

      public static String formatShape(int[] shape)
      Returns a string representing the shape of this object, if it is array-like. This will look something like "1024,1024,3" or "2,*".
      Parameters:
      shape - the shape to format
      Returns:
      a human-readable representation of the value shape
      See Also:

    • unformatShape

      public static int[] unformatShape(String txt)
      Takes a stringified version of the shape and turns it into an array. This performs the opposite of formatShape(int[]), so values are comma-separated, and the last one only may be "*".
      Parameters:
      txt - string representation of value shape
      Returns:
      array representation of value shape
      Throws:
      IllegalArgumentException - if the argument is not in a comprehensible format
      See Also:

    • unformatString

      public Object unformatString(String rep)
      Description copied from interface: ValueInfo
      Returns an object of the sort described by this ValueInfo represented by the given string rep.
      Specified by:
      unformatString in interface ValueInfo
      Parameters:
      rep - the string representation of a value described by this ValueInfo
      Returns:
      the Object value represented by rep; must match this info's content class (or be null)

    • toString

      public String toString()
      Returns a string representation of this object. The result indicates the object's name, class and shape.
      Overrides:
      toString in class Object
      Returns:
      a string representation of this object