Top Description Fields Constructors Methods
org.springframework.beans.support

public Class PropertyComparator<T>

extends Object
implements Comparator<T>
Class Inheritance
All Implemented Interfaces
java.util.Comparator
Type Parameters
<T>
the type of objects that may be compared by this comparator
Imports
java.util.Arrays, .Comparator, .List, org.apache.commons.logging.Log, .LogFactory, org.springframework.beans.BeanWrapperImpl, .BeansException, org.springframework.lang.Nullable, org.springframework.util.StringUtils
PropertyComparator performs a comparison of two beans, evaluating the specified bean property via a BeanWrapper.
Authors
Juergen Hoeller, Jean-Pierre Pawlak
Since
19.05.2003
See Also
org.springframework.beans.BeanWrapper

Field Summary

Modifier and TypeField and Description
protected final Log
logger

private final SortDefinition
sortDefinition

Constructor Summary

AccessConstructor and Description
public
PropertyComparator(SortDefinition sortDefinition)

Create a new PropertyComparator for the given SortDefinition.

public
PropertyComparator(String
the property to compare
property, boolean
whether upper and lower case in String values should be ignored
ignoreCase, boolean
whether to sort ascending (true) or descending (false)
ascending)

Create a PropertyComparator for the given settings.

Method Summary

Modifier and TypeMethod and Description
public int
compare(T
the first object to be compared.
o1, T
the second object to be compared.
o2)

Implements java.util.Comparator.compare.

Compares its two arguments for order.

private Object

Returns:

the property value
getPropertyValue(Object
the object to get the property value for
obj)

Get the SortDefinition's property value for the given object.

public final SortDefinition
getSortDefinition()

Return the SortDefinition that this comparator uses.

public static void
sort(List<?>
the input List
source, SortDefinition
the parameters to sort by
sortDefinition)

Sort the given List according to the given sort definition.

public static void
sort(Object[]
input source
source, SortDefinition
the parameters to sort by
sortDefinition)

Sort the given source according to the given sort definition.

Inherited from java.lang.Object:
cloneequalsfinalizegetClasshashCodenotifynotifyAlltoStringwaitwaitwait

Field Detail

loggerback to summary
protected final Log logger
sortDefinitionback to summary
private final SortDefinition sortDefinition

Constructor Detail

PropertyComparatorback to summary
public PropertyComparator(SortDefinition sortDefinition)

Create a new PropertyComparator for the given SortDefinition.

See Also
MutableSortDefinition
PropertyComparatorback to summary
public PropertyComparator(String property, boolean ignoreCase, boolean ascending)

Create a PropertyComparator for the given settings.

Parameters
property:String

the property to compare

ignoreCase:boolean

whether upper and lower case in String values should be ignored

ascending:boolean

whether to sort ascending (true) or descending (false)

Method Detail

compareback to summary
public int compare(T o1, T o2)

Implements java.util.Comparator.compare.

Doc from java.util.Comparator.compare.

Compares its two arguments for order. Returns a negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the second.

The implementor must ensure that signum(compare(x, y)) == -signum(compare(y, x)) for all x and y. (This implies that compare(x, y) must throw an exception if and only if compare(y, x) throws an exception.)

The implementor must also ensure that the relation is transitive: ((compare(x, y)>0) && (compare(y, z)>0)) implies compare(x, z)>0.

Finally, the implementor must ensure that compare(x, y)==0 implies that signum(compare(x, z))==signum(compare(y, z)) for all z.

Parameters
o1:T

the first object to be compared.

o2:T

the second object to be compared.

Returns:int

a negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the second.

Annotations
@Override
@SuppressWarnings:unchecked
getPropertyValueback to summary
private Object getPropertyValue(Object obj)

Get the SortDefinition's property value for the given object.

Parameters
obj:Object

the object to get the property value for

Returns:Object

the property value

Annotations
@Nullable
getSortDefinitionback to summary
public final SortDefinition getSortDefinition()

Return the SortDefinition that this comparator uses.

sortback to summary
public static void sort(List<?> source, SortDefinition sortDefinition) throws BeansException

Sort the given List according to the given sort definition.

Note

Contained objects have to provide the given property in the form of a bean property, i.e. a getXXX method.

Parameters
source:List<?>

the input List

sortDefinition:SortDefinition

the parameters to sort by

Exceptions
IllegalArgumentException:
in case of a missing propertyName
sortback to summary
public static void sort(Object[] source, SortDefinition sortDefinition) throws BeansException

Sort the given source according to the given sort definition.

Note

Contained objects have to provide the given property in the form of a bean property, i.e. a getXXX method.

Parameters
source:Object[]

input source

sortDefinition:SortDefinition

the parameters to sort by

Exceptions
IllegalArgumentException:
in case of a missing propertyName