Mega Code Archive
Predicate Chain ( Chaining of two or more predicates )
<![CDATA[
package com.googelcode.jpractices.common;
import org.apache.commons.lang.builder.ToStringBuilder;
/**
* Copyright 2009 @ jPractices v 1.0
* @SVN URL : http://jpractices.googlecode.com
* @author Ganesh Gowtham
* @Homepage : http://ganesh.gowtham.googlepages.com
*/
public class Person {
private String firstName;
private String lastName;
private int salary;
public Person(String firstName, String lastName, int salary) {
super();
this.firstName = firstName;
this.lastName = lastName;
this.salary = salary;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public int getSalary() {
return salary;
}
public void setSalary(int salary) {
this.salary = salary;
}
@Override
public String toString() {
return ToStringBuilder.reflectionToString(this);
}
}
---------------
package com.googelcode.jpractices;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import org.apache.commons.beanutils.BeanPredicate;
import org.apache.commons.collections.CollectionUtils;
import org.apache.commons.collections.Predicate;
import org.apache.commons.collections.PredicateUtils;
import org.apache.commons.collections.functors.EqualPredicate;
import com.googelcode.jpractices.common.Person;
/**
* Copyright 2009 @ jPractices v 1.0
* @SVN URL : http://jpractices.googlecode.com
* @author Ganesh Gowtham
* @Homepage : http://ganesh.gowtham.googlepages.com
*/
public class PredicateChainExample {
List<Person> personList = new ArrayList<Person>();
/**
* Basic method which creates the list of person object's
*
*/
void setUpData() {
personList.add(new Person("ganesh", "gowtham", 35000));
personList.add(new Person("britney", "spears", 45000));
personList.add(new Person("ganesh", "gowtham", 36000));
personList.add(new Person("ganesh", "dummy", 45000));
}
/**
*
* Here we are adding multiple predicate
* filters the collection so that final person object will contain
* firstName as "ganesh" & lastName as "gowtham"
*/
void filterDataUsingMultipleCriteria() {
EqualPredicate firstNameEqlPredicate = new EqualPredicate("ganesh");
BeanPredicate firtsNameBeanPredicate = new BeanPredicate("firstName", firstNameEqlPredicate);
EqualPredicate lastNameEqlPredicate2 = new EqualPredicate("gowtham");
BeanPredicate lastNameBeanPredicate2 = new BeanPredicate("lastName", lastNameEqlPredicate2);
Predicate[] allPredicateArray = { firtsNameBeanPredicate, lastNameBeanPredicate2 };
Predicate allPredicate = PredicateUtils.allPredicate(allPredicateArray);
Collection<Person> filteredCollection = CollectionUtils.select(personList, allPredicate);
for (Person person : filteredCollection) {
System.out.println(person);
}
}
public static void main(String[] args) {
PredicateChainExample chainExample = new PredicateChainExample();
chainExample.setUpData();
chainExample.filterDataUsingMultipleCriteria();
}
}
predicate_example3.zip( 811 k)
]]>