//Map example..........................

package collectctiondemo;

public class EmployeeData {

int empid;
String empname;
String empadd;
String empemail;
public int getEmpid() {
return empid;
}
public void setEmpid(int empid) {
this.empid = empid;
}
public String getEmpname() {
return empname;
}
public void setEmpname(String empname) {
this.empname = empname;
}
public String getEmpadd() {
return empadd;
}
public void setEmpadd(String empadd) {
this.empadd = empadd;
}
public String getEmpemail() {
return empemail;
}
public void setEmpemail(String empemail) {
this.empemail = empemail;
}


}

==============================================================================

package collectctiondemo;

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

public class MapEmployeeData {

public static void main(String[] args) {
Map<String, EmployeeData> m=new HashMap<String,EmployeeData>();
EmployeeData e1=new EmployeeData();
e1.setEmpid(101);
e1.setEmpname("govind");
e1.setEmpadd("madhubani");
e1.setEmpemail("govindkhan@gmail.com");
m.put("g", e1);

EmployeeData e2=new EmployeeData();
e2.setEmpid(102);
e2.setEmpname("murari");
e2.setEmpadd("sakri");
e2.setEmpemail("murari@gmail.com");
m.put("m", e2);

EmployeeData e3=new EmployeeData();
e3.setEmpid(103);
e3.setEmpname("satyam");
e3.setEmpadd("hanumannagar");
e3.setEmpemail("satyam@gmail.com");
m.put("s", e3);


EmployeeData e4=new EmployeeData();
e4.setEmpid(104);
e4.setEmpname("rishabh");
e4.setEmpadd("madhubani");
e4.setEmpemail("rishabh@gmail.com");
m.put("r", e4);

EmployeeData e5=new EmployeeData();
e5.setEmpid(105);
e5.setEmpname("shivam");
e5.setEmpadd("jhanjharpur");
e5.setEmpemail("shivam@gmail.com");
m.put("sh", e4);

EmployeeData e6=new EmployeeData();
e6.setEmpid(106);
e6.setEmpname("murlidhar");
e6.setEmpadd("madhubani");
e6.setEmpemail("murlidhar@gmail.com");
m.put("mu", e6);

Set<Entry<String, EmployeeData>> s = m.entrySet();
Iterator<Entry<String, EmployeeData>> it = s.iterator();
while (it.hasNext()) {
Entry<String, EmployeeData> kk = it.next();
String s1=kk.getKey();
System.out.println(s1);
EmployeeData vv = kk.getValue();
System.out.println(vv.getEmpid()+"----"+vv.getEmpname()+"----"+vv.getEmpadd()+"----"+vv.getEmpemail());


}
}

}
===============================================================================

o/p:--------------------
r
104----rishabh----madhubani----rishabh@gmail.com
s
103----satyam----hanumannagar----satyam@gmail.com
sh
104----rishabh----madhubani----rishabh@gmail.com
g
101----govind----madhubani----govindkhan@gmail.com
mu
106----murlidhar----madhubani----murlidhar@gmail.com
m
102----murari----sakri----murari@gmail.com

//Map Demonstration .................................
package collectctiondemo;

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

public class MapDemo {

public static void main(String[] args) {
Map<String, String> m=new HashMap<>();
m.put("g", "govind");
m.put("b", "ballabh");
m.put("k", "khan");
m.put("m", "madhubani");
m.put("h", "hanumannagar");
m.put("b", "bihar");//replace old value ballabh

System.out.println("---------map contains data in the form of key value-----------");
System.out.println(m);
System.out.println("----------Total Key--------------");
System.out.println(m.keySet());
System.out.println("-----------Total value-------------");
System.out.println(m.values());
System.out.println("----------How to iterate map------------");
Set<Entry<String, String>> s = m.entrySet();
Iterator<Entry<String, String>> it = s.iterator();
while (it.hasNext()) {
Entry<String, String> s1 = it.next();
String kk = s1.getKey();
System.out.println(kk);
String vv = s1.getValue();
System.out.println(vv);

}



}
}

o/p:-------------

---------map contains data in the form of key value-----------

{b=bihar, g=govind, h=hanumannagar, k=khan, m=madhubani}

----------Total Key--------------

[b, g, h, k, m]

-----------Total value-------------

[bihar, govind, hanumannagar, khan, madhubani]

----------How to iterate map------------

b

bihar

g

govind

h

hanumannagar

k

khan

m

madhubani

what is the difference between interface/abstract class and concrete class..........

===============================================================================================
interface:-
if we dont know anything about implementation just we have requirement specification
 (100% abstraction)  then we should go for interface.
example:- Servlet(Interface)

abstract class:-
if we are  talking about implementation but not completely
(partial implementation) then we should go for abstract class.
example:-GenericServlet/HttpServlet class.

Concrete class:-
if we are  talking about implementation  completely and ready to provide service
 then we should go for concrete  class.

example:-MyOwnServlet

================================================================================================
//NameAbstract.java//abstract class
//NameInterface.java//interface
//NameConcrete.java//concrete class
//NameMain.java
========================================================================

public abstract class NameAbstract {

public abstract String firstName();
public String lastname()
{
return "khan";
}

}

==============================================================================


public interface NameInterface {

public String middlename();

}


===============================================================================


public class NameConcrete extends NameAbstract implements NameInterface {

@Override
public String middlename() {
return "ballabh";
}

@Override
public String firstName() {
return "govind";
}


}


===============================================================================


public class NameMain {
public static void main(String[] args) {
NameConcrete nc=new NameConcrete();
String s1=nc.firstName();
String s2=nc.middlename();
String s3=nc.lastname();
System.out.println("Full name="+s1+" "+s2+" "+s3);
}

}


===============================================================================

o/p:-
Full name=govind ballabh khan


note:-

Abstract class :-----------
You cannot instantiate an abstract class.
An abstract class may contain abstract methods.
You need to inherit an abstract class to use it.
Concrete class:-----------
You can instantiate a concrete class.
A concrete class doesn’t have any abstract methods.
It is not mandatory to inherit a concrete class to use it.

Object sorting Using Comparator interface................................

//User.java
//UidComparator.java
//NameComparator.java
//UserMain.java
==============================================================================================


package collectctiondemo;

public class User {

int uid;
String uname;
String uaddress;
float salary;
public int getUid() {
return uid;
}
public void setUid(int uid) {
this.uid = uid;
}
public String getUname() {
return uname;
}
public void setUname(String uname) {
this.uname = uname;
}
public String getUaddress() {
return uaddress;
}
public void setUaddress(String uaddress) {
this.uaddress = uaddress;
}
public float getSalary() {
return salary;
}
public void setSalary(float salary) {
this.salary = salary;
}


}

===========================================================================

package collectctiondemo;

import java.util.Comparator;

public class UidComparator implements Comparator<User>{

@Override
public int compare(User u1, User u2) {

if(u1.getUid()>u2.getUid())
return 1;
else if(u1.getUid()<u2.getUid())
return -1;
else
    return 0;




}

}

================================================================================

package collectctiondemo;

import java.util.Comparator;

public class NameComparator implements Comparator<User> {

@Override
public int compare(User u1, User u2) {
return u1.getUname().compareTo(u2.getUname());
}

}


===============================================================================

package collectctiondemo;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class UserMain {
public static void main(String[] args) {
List<User> l=new ArrayList<User>();
User u1=new User();
u1.setUid(5);
u1.setUname("ballabh");
u1.setUaddress("madhubani");
u1.setSalary(26000.00f);
l.add(u1);


User u2=new User();
u2.setUid(3);
u2.setUname("govind");
u2.setUaddress("darbhangha");
u2.setSalary(16000.00f);
l.add(u2);


User u3=new User();
u3.setUid(4);
u3.setUname("mani");
u3.setUaddress("motihari");
u3.setSalary(48000.00f);
l.add(u3);



User u4=new User();
u4.setUid(6);
u4.setUname("ajit");
u4.setUaddress("patna");
u4.setSalary(59000.00f);
l.add(u4);

User u5=new User();
u5.setUid(9);
u5.setUname("sanjay");
u5.setUaddress("bhagalpur");
u5.setSalary(18000.00f);
l.add(u5);


System.out.println("---------------Before Sorting--------------");
for(User u:l)
{
System.out.println(u.getUid()+"-----"+u.getUname()+"-----"+u.getUaddress()+"-----"+u.getSalary());
}

Collections.sort(l,new UidComparator());

//Collections.sort(l,new NameComparator());

System.out.println("----------------After Sorting-----------------");
for(User u:l)
{
System.out.println(u.getUid()+"-----"+u.getUname()+"-----"+u.getUaddress()+"-----"+u.getSalary());
}
}

}



o/p:-------------------------

---------------Before Sorting--------------
5-----ballabh-----madhubani-----26000.0
3-----govind-----darbhangha-----16000.0
4-----mani-----motihari-----48000.0
6-----ajit-----patna-----59000.0
9-----sanjay-----bhagalpur-----18000.0
----------------After Sorting-----------------
3-----govind-----darbhangha-----16000.0
4-----mani-----motihari-----48000.0
5-----ballabh-----madhubani-----26000.0
6-----ajit-----patna-----59000.0
9-----sanjay-----bhagalpur-----18000.0

//Object sorting based on empid and based on empname using Comparable Interface........

package collectctiondemo;

public class Employee implements Comparable<Employee>{
int empid;
String empname;
String empaddress;
String email;
public int getEmpid() {
return empid;
}
public void setEmpid(int empid) {
this.empid = empid;
}
public String getEmpname() {
return empname;
}
public void setEmpname(String empname) {
this.empname = empname;
}
public String getEmpaddress() {
return empaddress;
}
public void setEmpaddress(String empaddress) {
this.empaddress = empaddress;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}

// based on empid...................
       @Override
public int compareTo(Employee e) {

if(empid>e.empid)
return 1;
else if(empid<e.empid)
return -1;
else
return 0;
//based  on empname.....................
//return empname.compareTo(e.empname);



}


}

===============================================================================

package collectctiondemo;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class EmployeeMain {
public static void main(String[] args) {
List<Employee> l=new ArrayList<Employee>();
Employee e1=new Employee();
e1.setEmpid(101);
e1.setEmpname("govind");
e1.setEmpaddress("madhubani");
e1.setEmail("govindkhan@gmail.com");
l.add(e1);

Employee e2=new Employee();
e2.setEmpid(107);
e2.setEmpname("ajit");
e2.setEmpaddress("patna");
e2.setEmail("ajitraj@gmail.com");
l.add(e2);

Employee e3=new Employee();
e3.setEmpid(104);
e3.setEmpname("mani");
e3.setEmpaddress("motihari");
e3.setEmail("mani@gmail.com");
l.add(e3);


Employee e4=new Employee();
e4.setEmpid(108);
e4.setEmpname("sanjay");
e4.setEmpaddress("bhagalpur");
e4.setEmail("sanjay@gmail.com");
l.add(e4);


Employee e5=new Employee();
e5.setEmpid(106);
e5.setEmpname("anand");
e5.setEmpaddress("darbhangha");
e5.setEmail("anand@gmail.com");
l.add(e5);
System.out.println("-------------before sorting--------------");
for(Employee emp:l)
{
System.out.println(emp.getEmpid()+" "+emp.getEmpname()+" "+emp.getEmpaddress()+" "+emp.getEmail());
}

Collections.sort(l);

System.out.println("-------------after sorting--------------");
for(Employee emp:l)
{
System.out.println(emp.getEmpid()+" "+emp.getEmpname()+" "+emp.getEmpaddress()+" "+emp.getEmail());
}


}

}
================================================================================


o/p:---------------------

-------------before sorting--------------
101 govind madhubani govindkhan@gmail.com
107 ajit patna ajitraj@gmail.com
104 mani motihari mani@gmail.com
108 sanjay bhagalpur sanjay@gmail.com
106 anand darbhangha anand@gmail.com
-------------after sorting--------------
101 govind madhubani govindkhan@gmail.com
104 mani motihari mani@gmail.com
106 anand darbhangha anand@gmail.com
107 ajit patna ajitraj@gmail.com
108 sanjay bhagalpur sanjay@gmail.com

wap to remove duplicate values from existing list (List l) and also create list of duplicate values (l2) and create list of non duplicate values (l1).

import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;

public class AssignmentCollection {
public static void main(String[] args) {
List<String> l=new ArrayList<String>();
  List<String> l1=new ArrayList<String>();
    List<String> l2=new ArrayList<String>();
    l.add("govind");
l.add("ballabh");
l.add("khan");
l.add("govind");
l.add("ballabh");
l.add("khan");
l.add("madhubani");
l.add("bihar");
System.out.println("--------List Contains Data----------");
for(String kk:l)
{
System.out.println(kk);
}

Iterator<String> it = l.iterator();
while (it.hasNext()) {
String s1 =  it.next();
int kk = Collections.frequency(l, s1);
System.out.println("frequency of :"+s1+"------"+kk+" times");
if(kk==1)
{
l1.add(s1);
}
else
{
l2.add(s1);
}

}
System.out.println("--------------unique final list---------------");
for(String kt:l1)
{
System.out.println(kt);
}

System.out.println("--------------duplicate final list---------------");
for(String km:l2)
{
System.out.println(km);
}
}
}

o/p:------------------------

--------List Contains Data----------

govind

ballabh

khan

govind

ballabh

khan

madhubani

bihar

frequency of :govind------2 times

frequency of :ballabh------2 times

frequency of :khan------2 times

frequency of :govind------2 times

frequency of :ballabh------2 times

frequency of :khan------2 times

frequency of :madhubani------1 times

frequency of :bihar------1 times

--------------unique final list---------------

madhubani

bihar

--------------duplicate final list---------------

govind

ballabh

khan

govind

ballabh

khan

wap to remove duplicate values from existing list (List l) and also create list of duplicate values (l2) and create list of non duplicate values (l1).

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;



public class UniqueDuplicate {
public static void main(String[] args) {
List<String> l=new ArrayList<String>();
  List<String> l1=new ArrayList<String>();
    List<String> l2=new ArrayList<String>();
l.add("govind");
l.add("ballabh");
l.add("khan");
l.add("govind");
l.add("ballabh");
l.add("khan");
l.add("madhubani");
l.add("bihar");
System.out.println("--------List Contains Data----------");
for(String k1:l)
{
System.out.println(k1);
}
 
Iterator<String>it1 = l.iterator();
    while (it1.hasNext()) {
String s1 = it1.next();
if(l1.contains(s1))
{
l2.add(s1);
}
else
{
l1.add(s1);
}
}
   
   
    System.out.println("----------------Duplicate value -----------------------");
    for(String k2:l2)
{
System.out.println(k2);
}
    System.out.println("----------------Unique value -----------------------");
    for(String k3:l1)
{
System.out.println(k3);
}
   
   
    Iterator<String> it = l1.iterator();
while (it.hasNext()) {
String kk =  it.next();
if(l2.contains(kk))
{
l2.add(kk);
}
}

if(l1.containsAll(l2))
{
l1.removeAll(l2);
}

System.out.println("----------------final Duplicate value -----------------------");
    for(String k4:l2)
{
System.out.println(k4);
}
   
    System.out.println("----------------final unique value -----------------------");
    for(String k5:l1)
{
System.out.println(k5);
}
}
}



o/p:-----------------------------------------

--------List Contains Data----------
govind
ballabh
khan
govind
ballabh
khan
madhubani
bihar
----------------Duplicate value -----------------------
govind
ballabh
khan
----------------Unique value -----------------------
govind
ballabh
khan
madhubani
bihar
----------------final Duplicate value -----------------------
govind
ballabh
khan
govind
ballabh
khan
----------------final unique value -----------------------
madhubani
bihar