Package org.omnifaces.persistence.criteria

Class Criteria<T>

java.lang.Object

org.omnifaces.persistence.criteria.Criteria<T>

Type Parameters:

T - The generic criteria value type.

Direct Known Subclasses:

Between, Bool, Enumerated, IgnoreCase, Like, Not, Numeric, Order

public abstract class Criteria<T>
extends Object

This is used by Page and BaseEntityService.getPage(Page, boolean). It defines a set of criteria which could be supplied as value of "required criteria" and "optional criteria" maps.

There are so far the following criteria:

• Not - to negate the value
• Like - to search a string value
• Order - to perform "less than" or "greater than" searches
• Between - to perform "between" searches
• Enumerated - to parse value as enum
• Numeric - to parse value as number
• Bool - to parse value as boolean
• IgnoreCase - to perform "ignore case" searches

You can create your own ones if you want to have more fine grained control over how criteria values are parsed and turned into a predicate.

An elaborate use case can be found in OptimusFaces project.

Author:

Bauke Scholtz

See Also:

Page, BaseEntityService

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	Criteria.ParameterBuilder	This is used in build(Expression, CriteriaBuilder, ParameterBuilder).

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	Criteria(T value)	Create criteria based on given value.

Method Summary

Modifier and Type	Method	Description
boolean	applies(Object modelValue)	Returns whether this criteria value would apply to the given model value.
abstract Predicate	build(Expression<?> path, CriteriaBuilder criteriaBuilder, Criteria.ParameterBuilder parameterBuilder)	Returns a predicate for the criteria value.
boolean	equals(Object object)
T	getValue()	Returns the criteria value.
int	hashCode()
String	toString()
static Object	unwrap(Object possibleCriteria)	Unwraps the criteria value from given object which could possibly represent a Criteria.

Methods inherited from class java.lang.Object

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

Constructor Detail

Criteria

protected Criteria(T value)

Create criteria based on given value.

Parameters:

value - The criteria value.

Throws:

IllegalArgumentException - When given criteria value cannot be reasonably parsed.

Method Detail

build

public abstract Predicate build(Expression<?> path,
                                CriteriaBuilder criteriaBuilder,
                                Criteria.ParameterBuilder parameterBuilder)

Returns a predicate for the criteria value. Below is an example implementation:

 return criteriaBuilder.equal(path, parameterBuilder.create(getValue()));
 

Parameters:

path - Entity property path. You can use this to inspect the target entity property.

criteriaBuilder - So you can build a predicate with a ParameterExpression.

parameterBuilder - You must use this to create a ParameterExpression for the criteria value.

Returns:

A predicate for the criteria value.

applies

public boolean applies(Object modelValue)

Returns whether this criteria value would apply to the given model value. This must basically represent the "plain Java" equivalent of the SQL behavior as achieved by build(Expression, CriteriaBuilder, ParameterBuilder).

Parameters:

modelValue - The model value to test this criteria on.

Returns:

Whether this criteria value would apply to the given model value.

Throws:

IllegalArgumentException - When given model value cannot be reasonably parsed.

UnsupportedOperationException - When this method is not implemented yet.

getValue

public T getValue()

Returns the criteria value.

Returns:

The criteria value.

unwrap

public static Object unwrap(Object possibleCriteria)

Unwraps the criteria value from given object which could possibly represent a Criteria.

Parameters:

possibleCriteria - Any object which could possibly represent a Criteria.

Returns:

The unwrapped criteria value when given object actually represents a Criteria, else the original value unmodified.

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object object)

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class Object