Java/j2Ee Discussions

[vijayjust4u]

[quote name='Java01' timestamp='1372794104' post='1303912292']
Comparator -- mayaaa nuvvu neetho inko edavani ppolchavu anukoo adi comparator

Comparable -- nuvvu ee DB lo ni idharu neeku istam aina vedavalani okaritho okarini polchavu anukooo adi comparable
[/quote]

ROFL Comment assal....

Here is the dipperence in java language...

Comparable: The “Comparable” allows itself to compare with another similar object (i.e. A class that implements Comparable becomes an object to be compared with). The method compareTo() is specified in the interface.

Comparatot: The Comparator is used to compare two different objects. The following method is specified in the Comparator interface. public int compare(Object o1, Object o2)

[vijayjust4u]

[quote name='cherlapalli_jailer' timestamp='1372788110' post='1303911744']
@sinni i modifed above and the working perfectly one is there...so pl try to use the above code now
[/quote]


Working mama... Thanks a lot....

[chinni005]

15mins skype call undhi final round anta ippude cheppadu vendor [size=4] [/size]

[king420]

[quote name='Sinnababu_SillyPulka' timestamp='1372797652' post='1303912589']

ROFL Comment assal....

Here is the dipperence in java language...

Comparable: The “Comparable” allows itself to compare with another similar object (i.e. A class that implements Comparable becomes an object to be compared with). The method compareTo() is specified in the interface.

Comparatot: The Comparator is used to compare two different objects. The following method is specified in the Comparator interface. public int compare(Object o1, Object o2)
[/quote]
[quote name='Java01' timestamp='1372794104' post='1303912292']
Comparator -- mayaaa nuvvu neetho inko edavani ppolchavu anukoo adi comparator

Comparable -- nuvvu ee DB lo ni idharu neeku istam aina vedavalani okaritho okarini polchavu anukooo adi comparable
[/quote]exzaamplee kavaliii similar kind of objects ante?

[vijayjust4u]

[quote name='HAPPYNESS' timestamp='1372797758' post='1303912601']
exzaamplee kavaliii similar kind of objects ante?
[/quote]

Comparable:
Many of the standard classes in the Java library like String, Integer, Date, File etc implement the Comparable interface to give the class a "Natural Ordering".

Comparator:
You can have more control by writing your Comparator class. For most cases natural ordering is fine as shown on the left but say we require a special scenario where we need to first sort by the id and then by Type. (Id and Type are attributes of a Class) We can achieve this by writing a “Comparator” class.

Example Class for Comparable:

public class Pet implements Comparable {
int petId;
String petType;
public Pet(int argPetId, String argPetType) {
petId = argPetId;
this.petType = argPetType;
}
public int compareTo(Object o) {
Pet petAnother = (Pet)o;
//[b]natural alphabetical ordering by type[/b]
//if equal returns 0, if greater returns +ve int,
//if less returns -ve int
return [b]this.petType.compareTo(petAnother.petType);[/b]
}
public static void main(String[] args) {
List list = new ArrayList();
list.add(new Pet(2, "Dog"));
list.add(new Pet(1, "Parrot"));
list.add(new Pet(2, "Cat"));
Collections.sort(list); // sorts using compareTo method
for (Iterator iter = list.iterator(); iter.hasNext() {
Pet element = (Pet) iter.next();
System.out.println(element);
}
}
public String toString() {
return petType;
}
}

If you want to sort first by Id and then Type, use Comparator.

[chinni005]

[quote name='HAPPYNESS' timestamp='1372797758' post='1303912601']
exzaamplee kavaliii similar kind of objects ante?
[/quote]

comparator example
class1:
public class People{
private String fn;
private String ln;
public People(String fn , String ln){
this.fn=fn;
this.ln=ln;
}
public String getFn(){
return fn;
}
public String getLn(){
return ln;
}

}


class2:
public class PeopleComparator implements Comparator<People>{


public int compare(People o1, People o2) {

return 0;
}

}

class3:

import java.util.*;
public class PeopleTest {

public static void main(String[] args) {
try
{

People p1 = new People("aj", "Jr");
People p2 = new People("aj", "Sr");
People p3 = new People("aj","Jhon");
Set<People> people = new TreeSet<People>();
people.add(p1);
people.add(p2);
people.add(p3);
Iterator<People> itr = people.iterator();
while(itr.hasNext()){
People p = itr.next();
System.out.println(p.getLn());
}
}
finally{

}

}
}

[cherlapalli_jailer]

think of shopping carts....or job searches setc....

and appy comparators to that ...u wiill get better picture

like take for example job search....try to compare the similar job like ...techs...etc..

[chinni005]

what happens if u add null values to

1.array list
2.HashMap

[chinni005]

guys evarayina unnara..naako help kaavali

[king420]

[quote name='Chinni_' timestamp='1372798958' post='1303912738']
what happens if u add null values to

1.array list
2.HashMap
[/quote]
emi avvadu .....Hash map memory ekkuva avtundi ..Array list fixed

[chinni005]

[quote name='HAPPYNESS' timestamp='1372799761' post='1303912801']
emi avvadu .....Hash map memory ekkuva avtundi ..[color=#ff0000][size=5]Array list fixed[/size][/color]
[/quote]
[size=4] arrays are fixed not array list..[/size]

[size=4]array list and vectors grow in size [/size]dynamically[size=4] [/size][size=4] .. [/size]

[Water]

[quote name='HAPPYNESS' timestamp='1372799761' post='1303912801']
emi avvadu .....Hash map memory ekkuva avtundi ..Array list fixed
[/quote]
neeku java kuda ochu endi [img]http://4.bp.blogspot.com/-lBbeM9C_140/Uc3C9Vjh3fI/AAAAAAAAH-s/F1dYmcvzYGk/s137/brahmam_fanski.gif[/img]

[chinni005]

[quote name='CNATION1' timestamp='1372800283' post='1303912816']
neeku java kuda ochu endi [img]http://4.bp.blogspot.com/-lBbeM9C_140/Uc3C9Vjh3fI/AAAAAAAAH-s/F1dYmcvzYGk/s137/brahmam_fanski.gif[/img]
[/quote]
[img]http://www.codeproject.com/KB/ajax/AjaxTutorial/AJAX2.jpg[/img]

[ZuniorVentiyar]

ooree nee eshaloooo ....... eee bomma lu endhi ... eee questions endhi ..... deshani brashtu patisthunavu kadhraa nayanaaa.....

[quote name='Chinni_' timestamp='1372800384' post='1303912822']
[img]http://www.codeproject.com/KB/ajax/AjaxTutorial/AJAX2.jpg[/img]
[/quote]

[king420]

[quote name='Java01' timestamp='1372801547' post='1303912875']
ooree nee eshaloooo ....... eee bomma lu endhi ... eee questions endhi ..... deshani brashtu patisthunavu kadhraa nayanaaa.....
[/quote]