Class DataType

Method Details

• getName

  public String getName()

  Returns the name for this data type.

  Returns:

  data type name

• getByteCount

  public int getByteCount()

  Returns the number of bytes used in a CDF to store a single item of this type.

  Returns:

  size in bytes

• getArrayElementClass

  public Class<?> getArrayElementClass()

  Returns the element class of an array that this data type can be read into. In most cases this is a primitive type or String.

  Returns:

  array raw value element class

• getScalarClass

  public Class<?> getScalarClass()

  Returns the type of objects obtained by the getScalar method.

  Returns:

  scalar type associated with this data type

• getGroupSize

  public int getGroupSize()

  Number of elements of type arrayElementClass that are read into valueArray for a single item read. This is usually 1, but not, for instance, for EPOCH16.

  Returns:

  number of array elements per item

• getArrayIndex

  public int getArrayIndex(int itemIndex)

  Returns the index into a value array which corresponds to the item'th element.

  Returns:

  itemIndex * groupSize

• hasMultipleElementsPerItem

  public boolean hasMultipleElementsPerItem()

  True if this type may turn a variable number of elements from the value array into a single read item. This is usually false, but true for character types, which turn into strings.

  Returns:

  true iff type may have multiple elements per read item

• getDefaultPadValueArray

  public Object getDefaultPadValueArray()

  Returns an array of array-class values containing a single item with the default pad value for this type.

  Returns:

  default raw pad value array

  See Also:

  • "Section 2.3.20 of CDF User's Guide"

• readValues

  public abstract void readValues(Buf buf, long offset, int nelPerItem, Object valueArray, int count) throws IOException

  Reads data of this data type from a buffer into an appropriately typed value array.

  Parameters:

  buf - data buffer

  offset - byte offset into buffer at which data starts

  nelPerItem - number of elements per item; usually 1, but may not be for strings

  valueArray - array to receive result data

  count - number of items to read

  Throws:

  IOException

• getScalar

  public abstract Object getScalar(Object valueArray, int arrayIndex)

  Reads a single item from an array which has previously been populated by readValues. The class of the returned value is that returned by getScalarClass().

  The arrayIndex argument is the index into the array object, not necessarily the item index - see the getArrayIndex method.

  Parameters:

  valueArray - array filled with data for this data type

  arrayIndex - index into array at which the item to read is found

  Returns:

  scalar representation of object at position index in valueArray

• formatScalarValue

  public String formatScalarValue(Object value)

  Provides a string view of a scalar value obtained for this data type.

  Parameters:

  value - value returned by getScalar

  Returns:

  string representation

• formatArrayValue

  public String formatArrayValue(Object array, int arrayIndex)

  Provides a string view of an item obtained from an array value of this data type.

  The arrayIndex argument is the index into the array object, not necessarily the item index - see the getArrayIndex method.

  Parameters:

  array - array value populated by readValues

  arrayIndex - index into array

  Returns:

  string representation

• toString

  public String toString()

  Overrides:

  toString in class Object

• getDataType

  public static DataType getDataType(int dataType, CdfInfo cdfInfo) throws CdfFormatException

  Returns a DataType corresponding to a CDF data type code, possibly customised for a particular CDF file.

  Currently, this returns the same as getDataType(int), except for TIME_TT2000 columns, in which case the last known leap second may be taken into account.

  Parameters:

  dataType - dataType field of AEDR or VDR

  cdfInfo - specifics of CDF file

  Returns:

  data type object

  Throws:

  CdfFormatException

• getDataType

  public static DataType getDataType(int dataType) throws CdfFormatException

  Returns the DataType object corresponding to a CDF data type code.

  Parameters:

  dataType - dataType field of AEDR or VDR

  Returns:

  data type object

  Throws:

  CdfFormatException