com.arsdigita.acs
Class SeekableSelection

java.lang.Object
  |
  +--com.arsdigita.acs.SeekableSelection

All Implemented Interfaces:

DataSource, MultiDataSource

public class SeekableSelection

extends java.lang.Object

implements MultiDataSource

Represents a generic multiple-row data source pulled in from the database. Stores all query results in memory because of the requirements of the templating system (must be able to traverse query results multiple times, must provide rowcount). Entity objects for doing logical operations on more specific database objects should extend Selection, adding additional accessors for derived properties as needed.

Fields inherited from interface com.arsdigita.acs.MultiDataSource

cvsId

Constructor Summary

SeekableSelection(java.lang.Object obj)
Casts the given object to SimpleResultSet

SeekableSelection(com.arsdigita.db.SimpleResultSet srs)
Creates a new SeekableSelection, initialized from a SimpleResultSet.

Method Summary

boolean	contains(java.lang.String column) Returns true if this contains a column named column.
java.lang.String	get(java.lang.String key) Returns the value of the column named by key.
java.lang.Object	getObject(java.lang.String key) Returns the value of the column named by key.
java.lang.String[]	keys() Returns a list of available keys (column names) in the Selection.
boolean	next() Advances to the next row in the data source, if there is one.
int	rowcount() Returns the number of rows in this datasource.
int	rownum() Returns the current row number in the datasource.
void	seek(int rownum) Sets the current row to the given (one-based) row number.

Methods inherited from class java.lang.Object

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

Constructor Detail

SeekableSelection

public SeekableSelection(java.lang.Object obj)
                  throws java.sql.SQLException

Casts the given object to SimpleResultSet

SeekableSelection

public SeekableSelection(com.arsdigita.db.SimpleResultSet srs)
                  throws java.sql.SQLException

Creates a new SeekableSelection, initialized from a SimpleResultSet.

Method Detail

contains

public boolean contains(java.lang.String column)
                 throws DataSourceException

Returns true if this contains a column named column.

Specified by:

contains in interface DataSource

seek

public void seek(int rownum)
          throws DataSourceException

Sets the current row to the given (one-based) row number. The initial value, before next() is called, is 0, so you need to call seek(0) if you want to reset the datasource to its initial state.

Specified by:

seek in interface MultiDataSource

get

public java.lang.String get(java.lang.String key)
                     throws DataSourceException

Returns the value of the column named by key. Returns null if the column value is null.

Specified by:

get in interface DataSource

Throws:

InvalidKeyException - if key is not found.

getObject

public java.lang.Object getObject(java.lang.String key)
                           throws DataSourceException

Returns the value of the column named by key. Returns null if the column value is null.

Throws:

InvalidKeyException - if key is not found.

next

public boolean next()
             throws DataSourceException

Advances to the next row in the data source, if there is one.

Specified by:

next in interface MultiDataSource

Returns:

true; or false if there are no more elements.

keys

public java.lang.String[] keys()
                        throws DataSourceException

Returns a list of available keys (column names) in the Selection.

Specified by:

keys in interface DataSource

rownum

public int rownum()
           throws DataSourceException

Returns the current row number in the datasource.

Specified by:

rownum in interface MultiDataSource

rowcount

public int rowcount()
             throws DataSourceException

Returns the number of rows in this datasource.

Specified by:

rowcount in interface MultiDataSource