Interface Tuple
- All Known Subinterfaces:
TupleSequence
- All Known Implementing Classes:
AbortTupleSequence
,CachedTupleSequence
,WrapperTuple
Different typed access methods are provided for retrieving the result of each column. It is up to the caller to keep track of which is the right one to use. It's done this way so that we can return primitive values.
Note that in most cases a Tuple
instance is also a
TupleSequence
. That means that once the TupleSequence has
been advanced to the next row, calling the Tuple methods will give
different values. It follows that calls to a Tuple instance should
be made and the results consumed synchronously before the next
iteration, such instances are generally not suitable for hanging
on to outside of an iteration step.
The point of separating the two interfaces is to make it clear when a client is only permitted to read the values and not to advance the iterator.
- Since:
- 25 Apr 2017
- Author:
- Mark Taylor
-
Method Summary
Modifier and TypeMethodDescriptionboolean
getBooleanValue
(int icol) Returns the value of a given column as a boolean.double
getDoubleValue
(int icol) Returns the value of a given column as a double.int
getIntValue
(int icol) Returns the value of a given column as an integer.long
getLongValue
(int icol) Returns the value of a given column as a long.getObjectValue
(int icol) Returns the value of a given column as an object.long
Returns the row index for the underlying data set.
-
Method Details
-
getRowIndex
long getRowIndex()Returns the row index for the underlying data set. Note this value may not undergo a simple increment between steps (if rows are excluded from the underlying data set it may increase by more than one in some cases).- Returns:
- row index of underlying table row
-
getObjectValue
Returns the value of a given column as an object. If that element of the tuple is not of object type, the result may not be useful.If the result is a mutable object, its value may be overwritten by subsequent calls to this method (especially following calls to
TupleSequence.next()
if this object also implementsTupleSequence
).- Parameters:
icol
- column index- Returns:
- value of element
icol
, presumed of object type
-
getDoubleValue
double getDoubleValue(int icol) Returns the value of a given column as a double. If that element of the tuple is not of numeric type, the result may not be useful.- Parameters:
icol
- column index- Returns:
- value of element
icol
, presumed of numeric type
-
getIntValue
int getIntValue(int icol) Returns the value of a given column as an integer. If that element of the tuple is not of numeric type, the result may not be useful.- Parameters:
icol
- column index- Returns:
- value of element
icol
, presumed of numeric type
-
getLongValue
long getLongValue(int icol) Returns the value of a given column as a long. If that element of the tuple is not of numeric type, the result may not be useful.- Parameters:
icol
- column index- Returns:
- value of element
icol
, presumed of numeric type
-
getBooleanValue
boolean getBooleanValue(int icol) Returns the value of a given column as a boolean. If that element of the table is not of boolean type, the result may not be useful.- Parameters:
icol
- column index- Returns:
- value of element
icol
, presumed of boolean type
-