org.apache.commons.beanutils
Class BeanComparator
java.lang.Object
org.apache.commons.beanutils.BeanComparator
- Comparator, Serializable
public class BeanComparator
extends java.lang.Object
implements Comparator, Serializable
This comparator compares two beans by the specified bean property.
It is also possible to compare beans based on nested, indexed,
combined, mapped bean properties. Please see the
PropertyUtilsBean
documentation for all property name possibilities.
Note: The BeanComparator passes the values of the specified
bean property to a ComparableComparator, if no comparator is
specified in the constructor. If you are comparing two beans based
on a property that could contain "null" values, a suitable
Comparator
or
ComparatorChain
should be supplied in the constructor.
BeanComparator() - Constructs a Bean Comparator without a property set.
|
BeanComparator(String property) - Constructs a property-based comparator for beans.
|
BeanComparator(String property, Comparator comparator) - Constructs a property-based comparator for beans.
|
int | compare(Object o1, Object o2) - Compare two JavaBeans by their shared property.
|
boolean | equals(Object o) - Two
BeanComparator 's are equals if and only if
the wrapped comparators and the property names to be compared
are equal.
|
Comparator | getComparator() - Gets the Comparator being used to compare beans.
|
String | getProperty() - Gets the property attribute of the BeanComparator
|
int | hashCode() - Hashcode compatible with equals.
|
void | setProperty(String property) - Sets the method to be called to compare two JavaBeans
|
comparator
private Comparator comparator
property
private String property
BeanComparator
public BeanComparator()
Constructs a Bean Comparator without a property set.
Note that this is intended to be used
only in bean-centric environments.
Until
setProperty(String)
is called with a non-null value.
this comparator will compare the Objects only.
BeanComparator
public BeanComparator(String property)
Constructs a property-based comparator for beans.
This compares two beans by the property
specified in the property parameter. This constructor creates
a
BeanComparator
that uses a
ComparableComparator
to compare the property values.
Passing "null" to this constructor will cause the BeanComparator
to compare objects based on natural order, that is
java.lang.Comparable
.
property
- String Name of a bean property, which may contain the
name of a simple, nested, indexed, mapped, or combined
property. See PropertyUtilsBean
for property query language syntax.
If the property passed in is null then the actual objects will be compared
BeanComparator
public BeanComparator(String property,
Comparator comparator)
Constructs a property-based comparator for beans.
This constructor creates
a BeanComparator that uses the supplied Comparator to compare
the property values.
property
- Name of a bean property, can contain the name
of a simple, nested, indexed, mapped, or combined
property. See PropertyUtilsBean
for property query language
syntax.comparator
- BeanComparator will pass the values of the
specified bean property to this Comparator.
If your bean property is not a comparable or
contains null values, a suitable comparator
may be supplied in this constructor.
compare
public int compare(Object o1,
Object o2)
Compare two JavaBeans by their shared property.
If
getProperty()
is null then the actual objects will be compared.
o1
- Object The first bean to get data from to compare againsto2
- Object The second bean to get data from to compare
- int negative or positive based on order
equals
public boolean equals(Object o)
Two BeanComparator
's are equals if and only if
the wrapped comparators and the property names to be compared
are equal.
o
- Comparator to compare to
- whether the the comparators are equal or not
getComparator
public Comparator getComparator()
Gets the Comparator being used to compare beans.
- the Comparator being used to compare beans
getProperty
public String getProperty()
Gets the property attribute of the BeanComparator
- String method name to call to compare.
A null value indicates that the actual objects will be compared
hashCode
public int hashCode()
Hashcode compatible with equals.
- the hash code for this comparator
setProperty
public void setProperty(String property)
Sets the method to be called to compare two JavaBeans
property
- String method name to call to compare
If the property passed in is null then the actual objects will be compared
Copyright (c) 2001-2007 - Apache Software Foundation