info.informatica.data
Interface Dataset

All Known Implementing Classes:

AbstractDataset, ArrayIteratorDataset, EmptyDataset, GenericDataset, IteratorDataset, ListDataset, ResultsetDataset, SampleDataset

public interface Dataset

Interface to access sets of generic data.

Version:

1.03

Author:

amengual at informatica dot info

Method Summary

void	close() Closes the Dataset.
Object	evaluate(String id) Sometimes you want to directly access a field or method and evaluate it, instead of getting the object and then accessing the field or calling the method.
int	findColumn(FieldName name) Finds the index of the given column name of the dataset.
String	getCatalogName(int i) Gets the designated data item's catalog name.
int	getColumnCount()
FieldName	getColumnName(int i) Gets the designated data item's column name.
Date	getDate(FieldName id) Returns Date of name id.
Date	getDate(int i) Returns Date of index i.
double	getDouble(FieldName id) Returns double of name id
double	getDouble(int i) Returns int of index i
Map<String,? extends Object>	getEnviron() Gets a global "environment" Map, if available.
int	getInt(FieldName id) Returns int of name id
int	getInt(int i) Returns int of index i
String	getLabel() Gets the label of this Set, or null if not available.
long	getLong(FieldName id) Returns long of name id
long	getLong(int i) Returns long of index i
Map<FieldName,Object>	getMap() Gets a name -> values map containing the current data row.
MetaData	getMetaData() Gets the meta data for this data set.
Dataset	getNestedSet(String datasetName) It is allowed to have another Datasets nested to the current Dataset row.
Object	getObject(FieldName id) Returns Object of name id
Object	getObject(int i) Returns Object of index i
String	getString(FieldName id) Returns String of name id.
String	getString(int i) Returns String of index i.
boolean	isAfterLast() Retrieves wether the dataset is after its last row.
boolean	isEmpty()
boolean	isLast() Retrieves wether the dataset is on its last row.
boolean	next() Positions the Dataset at the next row of data.
void	reset() Puts the Dataset cursor in the initial state, regardless of the current cursor state.
void	setEnviron(Map<String,? extends Object> environ) Sets a global "environment" Map.

Method Detail

getDate

Date getDate(FieldName id)
             throws DatasetException

Returns Date of name id.

Returns:

the Date value of name id.

Throws:

DatasetException - if the data repository produced an error.

getDate

Date getDate(int i)
             throws DatasetException

Returns Date of index i.

Returns:

the Date value of index i.

Throws:

DatasetException - if the data repository produced an error.

getDouble

double getDouble(FieldName id)
                 throws DatasetException

Returns double of name id

Throws:

DatasetException - if the data repository produced an error.

getDouble

double getDouble(int i)
                 throws DatasetException

Returns int of index i

Throws:

DatasetException - if the data repository produced an error.

getInt

int getInt(FieldName id)
           throws DatasetException

Returns int of name id

Throws:

DatasetException - if the data repository produced an error.

getInt

int getInt(int i)
           throws DatasetException

Returns int of index i

Throws:

DatasetException - if the data repository produced an error.

getObject

Object getObject(FieldName id)
                 throws DatasetException

Returns Object of name id

Throws:

DatasetException - if the data repository produced an error.

getObject

Object getObject(int i)
                 throws DatasetException

Returns Object of index i

Throws:

DatasetException - if the data repository produced an error.

getLong

long getLong(FieldName id)
             throws DatasetException

Returns long of name id

Throws:

DatasetException - if the data repository produced an error.

getLong

long getLong(int i)
             throws DatasetException

Returns long of index i

Throws:

DatasetException - if the data repository produced an error.

getString

String getString(FieldName id)
                 throws DatasetException

Returns String of name id.

Throws:

DatasetException - if the data repository produced an error.

getString

String getString(int i)
                 throws DatasetException

Returns String of index i.

Throws:

DatasetException - if the data repository produced an error.

evaluate

Object evaluate(String id)
                throws DatasetException

Sometimes you want to directly access a field or method and evaluate it, instead of getting the object and then accessing the field or calling the method. The evaluate method provides a way to do that, and when called it will either return a variable named id or a method evaluation of the style package.object.method.

Parameters:

id - Fully qualified function name (package.object.function) or fqfn

Returns:

the result given by the function, or the object itself if there is no function (dot not specified in fqfn), or null if the function or method are not available.

Throws:

DatasetException - if the data repository produced an error.

getLabel

String getLabel()

Gets the label of this Set, or null if not available.

isEmpty

boolean isEmpty()
                throws DatasetException

Returns:

true if the Dataset is empty, false otherwise.

Throws:

DatasetException

next

boolean next()
             throws DatasetException

Positions the Dataset at the next row of data.

Returns:

false if there were no more rows, true otherwise.

Throws:

DatasetException - if the data repository produced an error.

getColumnCount

int getColumnCount()
                   throws DatasetException

Returns:

the number of columns of this Dataset.

Throws:

DatasetException - if the data repository produced an error.

getCatalogName

String getCatalogName(int i)
                      throws DatasetException

Gets the designated data item's catalog name.

Throws:

DatasetException - if the data repository produced an error.

getColumnName

FieldName getColumnName(int i)
                        throws DatasetException

Gets the designated data item's column name.

Throws:

DatasetException

getMetaData

MetaData getMetaData()
                     throws DataException

Gets the meta data for this data set.

Returns:

the meta data for this data set, or null if not available.

Throws:

DataException - if the data repository produced an error.

isAfterLast

boolean isAfterLast()
                    throws DatasetException

Retrieves wether the dataset is after its last row.

Returns:

true if the dataset is after its last row, false otherwise.

Throws:

DatasetException - if the data repository produced an error.

isLast

boolean isLast()
               throws DatasetException

Retrieves wether the dataset is on its last row.

Evaluation of this method could be expensive.

Returns:

true if the dataset is on its last row, false otherwise.

Throws:

DatasetException - if the data repository produced an error.

reset

void reset()
           throws DatasetException

Puts the Dataset cursor in the initial state, regardless of the current cursor state.

This method allows the reuse of a Dataset object after all rows have been extracted by the use of the next() function.

This method is optional. Implementations are required to throw an UnsupportedOperationException in case they do not implement it.

Throws:

DatasetException - if an error happened when resetting the data.

UnsupportedOperationException - if method is not implemented.

close

void close()
           throws DatasetException

Closes the Dataset.

No further work is possible with the Dataset after closing it.

Throws:

DatasetException - if an error happens when closing the Dataset.

findColumn

int findColumn(FieldName name)
               throws DatasetException

Finds the index of the given column name of the dataset.

Returns:

the index of the given column name of the dataset, or -1 if the column name is not known.

Throws:

DatasetException - if an error happens when accessing the data.

getMap

Map<FieldName,Object> getMap()
                             throws DatasetException

Gets a name -> values map containing the current data row.

Optional operation.

Returns:

a Map with the current data row. Cannot return null.

Throws:

DatasetException - if an error happens when creating the Map.

IllegalStateException - if data is not available because of a state problem (for example, next() not been called).

UnsupportedOperationException - if the class does not support this method.

getEnviron

Map<String,? extends Object> getEnviron()

Gets a global "environment" Map, if available.

Returns:

a Map with the environment, or null if no environment is available.

setEnviron

void setEnviron(Map<String,? extends Object> environ)

Sets a global "environment" Map.

Parameters:

environ - a Map with the environment.

getNestedSet

Dataset getNestedSet(String datasetName)
                     throws DatasetException

It is allowed to have another Datasets nested to the current Dataset row.

This is an optional operation. Datasets not supporting it must throw an UnsupportedOperationException.

Parameters:

datasetName - the name of the requested Dataset.

Returns:

the Dataset nested into the current row.

Throws:

DatasetException - if the data repository produced an error.

UnsupportedOperationException - if this Dataset does not support nested Datasets.