|
|||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
public interface ValueInfo
Describes a value, for instance one obtained from cells in a given table column, or from a table parameter. This interface encapsulates the name, description, UCD etc, as well as information about the kind of object that the value can assume, such as Java class and array shape where applicable. It will normally be associated with a method which is declared to return one or more Objects; use of the information in this class can then be used to make additional sense of the object(s) thus returned.
Method Summary | |
---|---|
java.lang.String |
formatValue(java.lang.Object value,
int maxLength)
Returns a string representation of a given value described by this ValueInfo. |
java.lang.Class |
getContentClass()
Returns the java class of the values described by this object. |
java.lang.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. |
java.lang.String |
getName()
Returns the name of this object. |
int[] |
getShape()
Returns the shape associated with array value types. |
java.lang.String |
getUCD()
Returns the Unified Column Descriptor string applying to the values described by this object. |
java.lang.String |
getUnitString()
Returns a string representing the units of the values described by this object. |
java.lang.String |
getUtype()
Returns the Utype 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. |
java.lang.Object |
unformatString(java.lang.String rep)
Returns an object of the sort described by this ValueInfo represented by the given string rep. |
Method Detail |
---|
java.lang.String getName()
java.lang.String getUnitString()
java.lang.String getUCD()
UCD
java.lang.String getUtype()
null
if none is knownjava.lang.String getDescription()
java.lang.Class getContentClass()
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.
boolean isArray()
getContentClass().getComponentType()!=null
int[] getShape()
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).
int getElementSize()
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.
boolean isNullable()
DomainMapper[] getDomainMappers()
java.lang.String formatValue(java.lang.Object value, int maxLength)
value
- the value to representmaxLength
- the maximum number of characters in the returned
stringjava.lang.Object unformatString(java.lang.String rep)
rep
- the string representation of a value described by
this ValueInfo
|
|||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |