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

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

compare

public int compare(Object o1,
                   Object o2)

Specified by:

compare in interface Comparator