Predicate Chain ( Chaining of two or more predicate's ) : Predicate « Apache Common « Java

1. Java
2. Apache Common
3. Predicate

Predicate Chain ( Chaining of two or more predicate's )

  
 
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)

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1.	Custom Predicate
2.	Bean Predicate with Equal Predicate