how will i get my values from collection?

[maggie karve]

import java.util.HashMap;
import java.util.Map;
class Turtle implements Comparable<Turtle>{
int size;
String d;
Turtle y;
Integer x;
public Turtle(int s){
this.x=s;
}
public Turtle(String d){
this.d=d;
}
public Turtle(int s,String d){
this.x=s;
this.d=d;
}
public boolean equals(Object o){
return (this.x==(((Turtle)o).x));
}
public int compareTo(Turtle t) {
return x.compareTo(t.x);
}
}
public class TurtleTest {
public static void main(String[] args){
Map<Turtle,Turtle> lh=new HashMap<Turtle,Turtle>();
lh.put(new Turtle(1),new Turtle("srr"));
lh.put(new Turtle(34),new Turtle("we"));
lh.put(new Turtle(2),new Turtle("hkjh"));
lh.put(new Turtle(34),new Turtle("hkjhkjhjk"));
System.out.println(lh.size());
for (Entry<Turtle, Turtle> t:lh.entrySet())
System.out.println(t);
}
}

after running this code i get hashcode values..i want to get the primitive values the object is holding???how do i do that..
how do i get individual entry set and keyset seperately???

[Phungsuk Wangdu]

i dont get it
what is question

[Raju Champaklal]

Set s=lh.keySet(); will do it...you can also put generics to it

[maggie karve]

i am using maps...i want solution for maps....thanks

[Raju Champaklal]

dude you get a set when you want keyset

[Phungsuk Wangdu]

oh i am sorry i didnt knew this was against rules

[maggie karve]

it is not helping......

[W. Joe Smith]

 

James Carter wrote:check your pm

Please UseTheForumNotEmail to respond to questions. If there is a solution there are many others (myself included) that would like to see it.

Thanks!

[Wouter Oet]

It is not that hard. If you compile it then you'll get this message:

wouter@wouter-laptop:~/temp$ javac TurtleTest.java
TurtleTest.java:39: cannot find symbol
symbol : class Entry
location: class TurtleTest
for (Entry<Turtle, Turtle> t:lh.entrySet())
^
1 error

Saying that it cannot find that class. So just import it

import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry; 

But then it still does not want you want it to do because the hashCode method has not been implemented (A Map uses hashCode and equals to determine if objects are equal, not the comparable interface).
So implement the hashCode and equals methods properly. Total code:

import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
class Turtle{
int size;
String d;
Turtle y;
Integer x;
public Turtle(int s){
this.x=s;
}
public Turtle(String d){
this.d=d;
}
public Turtle(int s,String d){
this.x=s;
this.d=d;
}
@Override
public boolean equals(Object o){
if(o == null || !(o instanceof Turtle))
return false;
else
{
// Just comparing the Integer x sinds that is all we use in the Map
// Use all the field needed to compare if 2 Turtles are meaningful equal
// I use only the Integer x to keep it simple.
Turtle t = (Turtle)o;
if(t.x == null && x == null)
return true;
else if(t.x != null && x !=null)
return t.x.equals(x);
else return false;
}
}
@Override
public int hashCode()
{
if(x == null)
return 0;
else
return x.hashCode();
}
}
public class TurtleTest {
public static void main(String[] args){
Map<Turtle,Turtle> lh=new HashMap<Turtle,Turtle>();
lh.put(new Turtle(1),new Turtle("srr"));
lh.put(new Turtle(34),new Turtle("we"));
lh.put(new Turtle(2),new Turtle("hkjh"));
lh.put(new Turtle(34),new Turtle("hkjhkjhjk"));
System.out.println(lh.size());
for (Entry<Turtle, Turtle> t:lh.entrySet())
System.out.println(t);
}
} 

And then the output is 3 which is what we wanted/expected.

[Wouter Oet]

I forgot:

And if you want to output some values then use the Entry methods getKey() and getValue()

for (Entry<Turtle, Turtle> t:lh.entrySet())
System.out.println(t.getKey().x + " " + t.getValue().d); 

[maggie karve]

you are a genius !!!thanks Wouter.....