com.myjeeva.comparator
Class GenericComparator

java.lang.Object
  com.myjeeva.comparator.GenericComparator

All Implemented Interfaces:

Serializable, Comparator

public final class GenericComparator
extends Object
implements Comparator, Serializable

Sorting - Generic Comparator

Author:

Jeevanandam Madanagopal

See Also:

Serialized Form

Constructor Summary

GenericComparator(boolean sortAscending)
default constructor - assumes comparator for Type List

GenericComparator(String sortField)
constructor with sortField parameter for Derived type of Class default sorting is ascending order

GenericComparator(String sortField, boolean sortAscending)
constructor with sortField, sortAscending parameter for Derived type of Class

Method Summary

int	compare(Object o1, Object o2)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.Comparator

equals

Constructor Detail

GenericComparator

public GenericComparator(boolean sortAscending)

default constructor - assumes comparator for Type List

For Example-

List<Integer> aa = new ArrayList<Integer>();
List<String> bb = new ArrayList<String>();
List<Date> cc = new ArrayList<Date>();

and so on..

Invoking sort method with passing GenericComparator for
Collections.sort(aa, new GenericComparator(false));

Parameters:

sortAscending - - a boolean - true ascending order or false descending order

GenericComparator

public GenericComparator(String sortField)

constructor with sortField parameter for Derived type of Class default sorting is ascending order

For Example-

PersonVO person = new PersonVO();
person.setId(10001);
person.setName("Jacob");
person.setHeight(5.2F);
person.setEmailId("[email protected]");
person.setSalary(10500L);
person.setDob(new SimpleDateFormat("MMMM d, yyyy", Locale.ENGLISH).parse("Jan 1, 1970"));


and person2, person3, so on.. And Defining & adding all the created objects in to below list

List<PersonVO> persons = new ArrayList<PersonVO>();
persons.add(person1);
persons.add(person2);
persons.add(person3); and so on

Invoking sort method with passing GenericComparator for
Collections.sort(persons, new GenericComparator("name"));

Parameters:

sortField - - a String - which field requires sorting; as per above example "sorting required for name field"

GenericComparator

public GenericComparator(String sortField,
                         boolean sortAscending)

constructor with sortField, sortAscending parameter for Derived type of Class

For Example-

PersonVO person = new PersonVO();
person.setId(10001);
person.setName("Jacob");
person.setHeight(5.2F);
person.setEmailId("[email protected]");
person.setSalary(10500L);
person.setDob(new SimpleDateFormat("MMMM d, yyyy", Locale.ENGLISH).parse("Jan 1, 1970"));


and person2, person3, so on.. And Defining & adding all the created objects in to below list

List<PersonVO> persons = new ArrayList<PersonVO>();
persons.add(person1);
persons.add(person2);
persons.add(person3); and so on

Invoking sort method with passing GenericComparator for
Collections.sort(persons, new GenericComparator("name"), false);

Parameters:

sortField - - a String - which field requires sorting; as per above example "sorting required for name field"

sortAscending - - a boolean - true ascending order or false descending order

Method Detail

compare

public int compare(Object o1,
                   Object o2)

Specified by:

compare in interface Comparator