com.peter.db
Class DBMatrix

java.lang.Object
  |
  +--com.peter.db.DBMatrix

All Implemented Interfaces:

java.io.Serializable

public class DBMatrix

extends java.lang.Object

implements java.io.Serializable

This class creates a data structure (Matrix) from a ResultSet, in order to that data retrieved from a ResultSet can be used after the ResultSet, and its Statement are no longer needed and can be closed. The data structure used is a HashMap that uses the original ResultSet column names as keys, and Vectors containing data objects as values.

Version:

$Revision: 1.0.1, 2003-11-04 $

Author:

Peter Larsson

See Also:

Serialized Form

Constructor Summary

DBMatrix(java.sql.ResultSet rs)
The constructor creates an instance of the structure given a ResultSet.

Method Summary

java.util.Vector	getColumn(int column) Returns a Vector containing all values in a column
java.util.Vector	getColumn(java.lang.String column) Returns a Vector containing all values in a column
java.util.Vector	getColumnNames() Returns a Vector containing all column names
java.util.HashMap	getData() Returns the whole data structure.
int	getNoOfColumns() Returns the number of columns of the matrix
int	getNoOfRows() Returns the number of rows
java.util.HashMap	getRowAsHashMap(int row) Returns a HashMap that contains column names as key, and row data as values, given a row number.
java.lang.Object	getValue(int row, int column) Returns a single value from the structure given a row number and a column number.
java.lang.Object	getValue(int row, java.lang.String columnName) Returns a single value from the structure given a row number and a column name.
boolean	isEmpty() Checks if the matrix is empty or not.
java.lang.String	toString() A textual representation of the matrix

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

DBMatrix

public DBMatrix(java.sql.ResultSet rs)
         throws java.sql.SQLException

The constructor creates an instance of the structure given a ResultSet.

Parameters:

rs - The ResultSet to convert.

Throws:

java.sql.SQLException - if there is a SQL error

Method Detail

getRowAsHashMap

public java.util.HashMap getRowAsHashMap(int row)

Returns a HashMap that contains column names as key, and row data as values, given a row number.

Parameters:

row - The row to retrieve values from.

Returns:

Returns a HashMap with column names as keys, and row data as values. Returns null if row is bigger than the number of rows in the structure.

getValue

public java.lang.Object getValue(int row,
                                 int column)

Returns a single value from the structure given a row number and a column number.

Parameters:

row - The row index

column - The column index

Returns:

An Object value from the structure

getValue

public java.lang.Object getValue(int row,
                                 java.lang.String columnName)

Returns a single value from the structure given a row number and a column name.

Parameters:

row - The row index

columnName - The name of the column

Returns:

A single value from the structure

getData

public java.util.HashMap getData()

Returns the whole data structure.

Returns:

The whole data structure.

getNoOfColumns

public int getNoOfColumns()

Returns the number of columns of the matrix

Returns:

Returns the number of columns of the matrix

getNoOfRows

public int getNoOfRows()

Returns the number of rows

Returns:

The number of rows in the matrix

getColumnNames

public java.util.Vector getColumnNames()

Returns a Vector containing all column names

Returns:

a Vector containing all column names

getColumn

public java.util.Vector getColumn(int column)

Returns a Vector containing all values in a column

Parameters:

column - The column index to return

Returns:

The data in the requested column

getColumn

public java.util.Vector getColumn(java.lang.String column)

Returns a Vector containing all values in a column

Parameters:

column - The column name to return

Returns:

The data in the requested column

isEmpty

public boolean isEmpty()

Checks if the matrix is empty or not.

Returns:

True if the matrix does not contain any rows, or false otherwise

toString

public java.lang.String toString()

A textual representation of the matrix

Overrides:

toString in class java.lang.Object

Returns:

A textual representation of the matrix