Class BeanPropertyValueEqualsPredicate
- java.lang.Object
-
- org.apache.commons.beanutils.BeanPropertyValueEqualsPredicate
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- All Implemented Interfaces:
org.apache.commons.collections.Predicate
public class BeanPropertyValueEqualsPredicate extends java.lang.Object implements org.apache.commons.collections.Predicate
Predicate
that evaluates a property value against a specified value.An implementation of
org.apache.commons.collections.Predicate
that evaluates a property value on the object provided against a specified value and returnstrue
if equal;false
otherwise. TheBeanPropertyValueEqualsPredicate
constructor takes two parameters which determine what property will be evaluated on the target object and what its expected value should be.-
public BeanPropertyValueEqualsPredicate( String propertyName, Object propertyValue )
-
Will create a
Predicate
that will evaluate the target object and returntrue
if the property specified bypropertyName
has a value which is equal to the the value specified bypropertyValue
. Or returnfalse
otherwise.
Note: Property names can be a simple, nested, indexed, or mapped property as defined by
org.apache.commons.beanutils.PropertyUtils
. If any object in the property path specified bypropertyName
isnull
then the outcome is based on the value of theignoreNull
attribute.A typical usage might look like:
// create the closure BeanPropertyValueEqualsPredicate predicate = new BeanPropertyValueEqualsPredicate( "activeEmployee", Boolean.FALSE ); // filter the Collection CollectionUtils.filter( peopleCollection, predicate );
This would take a
Collection
of person objects and filter out any people whoseactiveEmployee
property isfalse
. Assuming...-
The top level object in the
peeopleCollection
is an object which represents a person. -
The person object has a
getActiveEmployee()
method which returns the boolean value for the object'sactiveEmployee
property.
Another typical usage might look like:
// create the closure BeanPropertyValueEqualsPredicate predicate = new BeanPropertyValueEqualsPredicate( "personId", "456-12-1234" ); // search the Collection CollectionUtils.find( peopleCollection, predicate );
This would search a
Collection
of person objects and return the first object whosepersonId
property value equals456-12-1234
. Assuming...-
The top level object in the
peeopleCollection
is an object which represents a person. -
The person object has a
getPersonId()
method which returns the value for the object'spersonId
property.
- Version:
- $Id: BeanPropertyValueEqualsPredicate.java 1540509 2013-11-10 18:39:11Z oheger $
- See Also:
PropertyUtils
,Predicate
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Field Summary
Fields Modifier and Type Field Description private boolean
ignoreNull
Shouldnull
objects in the property path be ignored?private org.apache.commons.logging.Log
log
For logging.private java.lang.String
propertyName
The name of the property which will be evaluated when thisPredicate
is executed.private java.lang.Object
propertyValue
The value that the property specified bypropertyName
will be compared to when thisPredicate
executes.
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Constructor Summary
Constructors Constructor Description BeanPropertyValueEqualsPredicate(java.lang.String propertyName, java.lang.Object propertyValue)
Constructor which takes the name of the property, its expected value to be used in evaluation, and assumesignoreNull
to befalse
.BeanPropertyValueEqualsPredicate(java.lang.String propertyName, java.lang.Object propertyValue, boolean ignoreNull)
Constructor which takes the name of the property, its expected value to be used in evaluation, and a boolean which determines whethernull
objects in the property path will genenerate anIllegalArgumentException
or not.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description boolean
evaluate(java.lang.Object object)
Evaulates the object provided against the criteria specified when thisBeanPropertyValueEqualsPredicate
was constructed.protected boolean
evaluateValue(java.lang.Object expected, java.lang.Object actual)
Utility method which evaluates whether the actual property value equals the expected property value.java.lang.String
getPropertyName()
Returns the name of the property which will be evaluated when thisPredicate
is executed.java.lang.Object
getPropertyValue()
Returns the value that the property specified bypropertyName
will be compared to when thisPredicate
executes.boolean
isIgnoreNull()
Returns the flag which determines whethernull
objects in the property path will genenerate anIllegalArgumentException
or not.
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Field Detail
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log
private final org.apache.commons.logging.Log log
For logging.
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propertyName
private java.lang.String propertyName
The name of the property which will be evaluated when thisPredicate
is executed.
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propertyValue
private java.lang.Object propertyValue
The value that the property specified bypropertyName
will be compared to when thisPredicate
executes.
-
ignoreNull
private boolean ignoreNull
Should
null
objects in the property path be ignored?Determines whether
null
objects in the property path will genenerate anIllegalArgumentException
or not. If set totrue
then if any objects in the property path evaluate tonull
then theIllegalArgumentException
throw byPropertyUtils
will be logged but not rethrown andfalse
will be returned. If set tofalse
then if any objects in the property path evaluate tonull
then theIllegalArgumentException
throw byPropertyUtils
will be logged and rethrown.
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Constructor Detail
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BeanPropertyValueEqualsPredicate
public BeanPropertyValueEqualsPredicate(java.lang.String propertyName, java.lang.Object propertyValue)
Constructor which takes the name of the property, its expected value to be used in evaluation, and assumesignoreNull
to befalse
.- Parameters:
propertyName
- The name of the property that will be evaluated against the expected value.propertyValue
- The value to use in object evaluation.- Throws:
java.lang.IllegalArgumentException
- If the property name provided is null or empty.
-
BeanPropertyValueEqualsPredicate
public BeanPropertyValueEqualsPredicate(java.lang.String propertyName, java.lang.Object propertyValue, boolean ignoreNull)
Constructor which takes the name of the property, its expected value to be used in evaluation, and a boolean which determines whethernull
objects in the property path will genenerate anIllegalArgumentException
or not.- Parameters:
propertyName
- The name of the property that will be evaluated against the expected value.propertyValue
- The value to use in object evaluation.ignoreNull
- Determines whethernull
objects in the property path will genenerate anIllegalArgumentException
or not.- Throws:
java.lang.IllegalArgumentException
- If the property name provided is null or empty.
-
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Method Detail
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evaluate
public boolean evaluate(java.lang.Object object)
Evaulates the object provided against the criteria specified when thisBeanPropertyValueEqualsPredicate
was constructed. Equality is based on either reference or logical equality as defined by the property object's equals method. If any object in the property path leading up to the target property isnull
then the outcome will be based on the value of theignoreNull
attribute. By default,ignoreNull
isfalse
and would result in anIllegalArgumentException
if an object in the property path leading up to the target property isnull
.- Specified by:
evaluate
in interfaceorg.apache.commons.collections.Predicate
- Parameters:
object
- The object to be evaluated.- Returns:
- True if the object provided meets all the criteria for this
Predicate
; false otherwise. - Throws:
java.lang.IllegalArgumentException
- If an IllegalAccessException, InvocationTargetException, or NoSuchMethodException is thrown when trying to access the property specified on the object provided. Or if an object in the property path provided isnull
andignoreNull
is set tofalse
.
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evaluateValue
protected boolean evaluateValue(java.lang.Object expected, java.lang.Object actual)
Utility method which evaluates whether the actual property value equals the expected property value.- Parameters:
expected
- The expected value.actual
- The actual value.- Returns:
- True if they are equal; false otherwise.
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getPropertyName
public java.lang.String getPropertyName()
Returns the name of the property which will be evaluated when thisPredicate
is executed.- Returns:
- The name of the property which will be evaluated when this
Predicate
is executed.
-
getPropertyValue
public java.lang.Object getPropertyValue()
Returns the value that the property specified bypropertyName
will be compared to when thisPredicate
executes.- Returns:
- The value that the property specified by
propertyName
will be compared to when thisPredicate
executes.
-
isIgnoreNull
public boolean isIgnoreNull()
Returns the flag which determines whethernull
objects in the property path will genenerate anIllegalArgumentException
or not. If set totrue
then if any objects in the property path evaluate tonull
then theIllegalArgumentException
throw byPropertyUtils
will be logged but not rethrown andfalse
will be returned. If set tofalse
then if any objects in the property path evaluate tonull
then theIllegalArgumentException
throw byPropertyUtils
will be logged and rethrown.- Returns:
- The flag which determines whether
null
objects in the property path will genenerate anIllegalArgumentException
or not.
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