org.josef.jdbc

Class OrderByColumn

java.lang.Object

org.josef.jdbc.OrderByColumn

All Implemented Interfaces:

Serializable

@Status(stage=PRODUCTION,
        unitTests=COMPLETE)
 @Reviews(value=@Review(by="Kees Schotanus",at="2009-04-13"))
public class OrderByColumn
extends Object
implements Serializable

Abstraction of a column used in an order by clause.
In an order by clause, simple column names are used most often. It is however possible to use a DECODE() function call in an order by clause. This allows you to order on a value (description) that you attach to a code. See: OrderByColumn(String, Order, Class) for further information.

Version:

1.0 $Revision: 5877 $

Author:

Kees Schotanus

See Also:

OrderByClause, Serialized Form

Constructor Summary

Constructors

Constructor and Description
OrderByColumn(OrderByColumn orderByColumn) Copy constructor.
OrderByColumn(String columnName) Constructs this OrderByColumn from the supplied columnName.
OrderByColumn(String columnName, Order order) Constructs this OrderByColumn from the supplied columnName and order.
OrderByColumn(String columnName, Order order, Class<T> enumeration) Constructs this OrderByColumn that will be ordered using a decode function.

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object object) Determines whether this OrderByColumn is equal to the supplied object.
String	getColumnName() Gets the name of this OrderByColumn.
Order	getOrdering() Gets the order of this OrderByColumn.
int	hashCode() Computes the hash code of this OrderByColumn.
Order	setOrdering(Order order) Sets the order for this OrderByColumn.
void	toggleOrdering() Toggles the order (ascending/descending) for this OrderByColumn.
String	toOrderByString(Locale locale) Creates a String that can be used in an order by clause.
String	toString() Creates a String representation of this OrderByColumn.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

OrderByColumn

public OrderByColumn(OrderByColumn orderByColumn)

Copy constructor.

Parameters:

orderByColumn - The OrderByColumn to copy information from.

Throws:

NullPointerException - When the supplied orderByColumn is null.

OrderByColumn

public OrderByColumn(String columnName)

Constructs this OrderByColumn from the supplied columnName.
The order will be ascending by default.

Parameters:

columnName - Name of the column.

Throws:

IllegalArgumentException - When the supplied columnName is empty.

NullPointerException - When the supplied columnName is null.

OrderByColumn

public OrderByColumn(String columnName,
                     Order order)

Constructs this OrderByColumn from the supplied columnName and order.

Parameters:

columnName - Name of the column.

order - The order for this OrderByColumn.

Throws:

IllegalArgumentException - When the supplied columnName is empty.

NullPointerException - When either the supplied columnName or order is null.

OrderByColumn

public OrderByColumn(String columnName,
                     Order order,
                     Class<T> enumeration)

Constructs this OrderByColumn that will be ordered using a decode function.
A decode function looks like this: decode(expression, code, value [,code, value]... [,defaultValue])
The code/value pairs come from the supplied localizableEnumerations.

Type Parameters:

T - Type of the enumeration.

Parameters:

columnName - Name of the column.
This name will be used as the expression.

order - The order for this OrderByColumn.

enumeration - The enumeration to get the code/value pairs from.

Throws:

IllegalArgumentException - When the supplied columnName is empty.

NullPointerException - When either the supplied columnName, order or enumeration is null.

Method Detail

getColumnName

public String getColumnName()

Gets the name of this OrderByColumn.

Returns:

The name of this OrderByColumn.

getOrdering

public Order getOrdering()

Gets the order of this OrderByColumn.

Returns:

The order of this OrderByColumn.

setOrdering

public Order setOrdering(Order order)

Sets the order for this OrderByColumn.

Parameters:

order - The order for this OrderByColumn.

Returns:

Previous order.

Throws:

NullPointerException - When the supplied order is null.

toggleOrdering

public void toggleOrdering()

Toggles the order (ascending/descending) for this OrderByColumn.

equals

public boolean equals(Object object)

Determines whether this OrderByColumn is equal to the supplied object.
Both objects are equal when all of the following conditions are met:

• The supplied object is of type OrderByColumn
• The column names in both objects are the same
• Enumerations should be absent in both objects or present in both objects. When enumerations are present they should be of the same type.

Overrides:

equals in class Object

Parameters:

object - The object to compare to.

Returns:

True when this OrderByColumn is equal to the supplied object.

hashCode

public int hashCode()

Computes the hash code of this OrderByColumn.
The hash code is equal to the hash code of the column's name.

Overrides:

hashCode in class Object

Returns:

Hash code of this OrderByColumn.

toString

public String toString()

Creates a String representation of this OrderByColumn.
The format of this String is: column_name [ASC|DESC] [decoded by class_of_enumerated_type]
In text: the output consists of the name of the column, a space and then either ASC or DESC. Optionally, when enumerations are used for this OrderByColumn, a space followed by 'decoded by class_of_enumeration' is added.

Overrides:

toString in class Object

Returns:

String representation of this OrderByColumn.

toOrderByString

public String toOrderByString(Locale locale)

Creates a String that can be used in an order by clause.
The format of this String is either: column_name[ DESC] for a simple column or
DECODE(column_name, code, value [,code, value]...)[ DESC] for columns that need a decode function to be ordered by. The values are localized by using the supplied locale.

Parameters:

locale - The Locale to localize the description of the localized constants that server as the values in the DECODE function.
When null is supplied the default Locale will be used.

Returns:

A String that can be used in an order by clause.