Practical 9 Java

 

PRACTICAL 9

Collection API

9-(1)

1. Write a program to demostrate user of ArrayList, LinkedList ,LinkedHashMap, TreeMap and HashSet Class. And also implement CRUD operation without database connection using Collection API.

package com.company; import java.util.*; public class Main {

public static void main(String args[]){ Vector<Integer> v1=new Vector<Integer>(); v1.add(4);

v1.add(6);

v1.add(2);

v1.add(1); System.out.println("ARRAY LIST");

ArrayList<Integer> al=new ArrayList<Integer>(); al.addAll(v1);

al.add(3); System.out.println(al); al.clear(); System.out.println(al);

System.out.println("LINKED LIST"); LinkedList<Integer> ll = new LinkedList<Integer>(); ll.addAll(v1);

ll.add(9);

ll.add(7); ll.addLast(3); ll.addFirst(0); ll.add(4, 8); System.out.println(ll); ll.remove(2);

ll.remove(3); ll.removeFirst(); ll.removeLast(); if(ll.contains(7)) {

System.out.println("linked list contains object 7 of type Integer");

}

System.out.println(ll); System.out.println("LINKED HASH MAP"); LinkedHashMap<Integer, Integer> lhm

 

= new LinkedHashMap<Integer, Integer>(); lhm.put(1,73);

lhm.put(2, 47);

lhm.put(3, 45);

lhm.put(4, 24); System.out.println(lhm);

System.out.println("Getting value for key 1: "+ lhm.get(1)); System.out.println("Size of the map: "+ lhm.size()); System.out.println("Is map empty? " + lhm.isEmpty()); System.out.println("Contains key 2? "+ lhm.containsKey(2));

System.out.println("Contains value 24 and 47? "+ lhm.containsValue(47 + 24)); System.out.println("delete element 1: "+ lhm.remove(1)); System.out.println("Mappings of LinkedHashMap : "+ lhm); System.out.println("TREE MAP");

TreeMap<String, Integer> num = new TreeMap<>(); num.put("One", 1);

num.put("Two", 2);

num.put("Three", 3); System.out.println("TreeMap: " + num); int value1 = num.remove("Two");

System.out.println("Removed value: " + value1); boolean result1 = num.remove("Three", 3);

System.out.println("Is the entry {Three=3} removed? " + result1); System.out.println("Updated TreeMap: " + num); System.out.println("HASHSET");

HashSet<Integer> evenNumber = new HashSet<>(); evenNumber.add(2);

evenNumber.add(4); evenNumber.add(6);

System.out.println("HashSet: " + evenNumber); HashSet<Integer> numbers2 = new HashSet<>(); numbers2.addAll(evenNumber); numbers2.add(5);

System.out.println("New HashSet: " + numbers2);

}

}

CRUD OPERATION:

package com.company; import java.util.*;

 

class Employee{ private int empno;

private String ename; private int salary;

Employee(int empno, String ename, int salary){ this.empno = empno;

this.ename = ename; this.salary = salary;

}

public int getEmpno(){ return empno;

}

public int getSalary(){ return salary;

}

public String getEname(){ return ename;

}

public String toString(){

return empno+" "+ename+" "+salary;

}

}

class CRUDDemo{

public static void main(String[] args) {

 

List<Employee> c = new ArrayList<Employee>(); Scanner s = new Scanner(System.in);

Scanner s1 = new Scanner(System.in); int ch;

do{

System.out.println("1.INSERT"); System.out.println("2.DISPLAY"); System.out.println("3.SEARCH"); System.out.println("4.DELETE"); System.out.println("5.UPDATE"); System.out.print("Enter Your Choice : "); ch = s.nextInt();

switch(ch){ case 1:

System.out.print("Enter Empno : "); int eno = s.nextInt();

System.out.print("Enter EmpName : "); String ename = s1.nextLine(); System.out.print("Enter Salary : ");

int salary = s.nextInt();

c.add(new Employee(eno,ename,salary)); break;

case 2:

 

Iterator<Employee> i = c.iterator(); while(i.hasNext()){

Employee e = i.next(); System.out.println(e);

}

break; case 3:

boolean found = false; System.out.print("Enter Empno to Search :"); int empno = s.nextInt();

i = c.iterator(); while(i.hasNext()){

Employee e = i.next(); if(e.getEmpno() == empno) {

System.out.println(e); found = true;

}

}

if(!found){

System.out.println("Record Not Found");

}

break;

 

case 4:

found = false;

System.out.print("Enter Empno to Delete :"); empno = s.nextInt();

i = c.iterator(); while(i.hasNext()){

Employee e = i.next(); if(e.getEmpno() == empno) {

i.  remove(); found = true;

}

}

if(!found){

System.out.println("Record Not Found");

}else{

System.out.println("Record is Deleted Successfully...!");

}

break; case 5:

found = false;

System.out.print("Enter Empno to Update :"); empno = s.nextInt();

ListIterator<Employee>li = c.listIterator(); while(li.hasNext()){

 

Employee e = li.next(); if(e.getEmpno() == empno) {

System.out.print("Enter new Name : "); ename = s1.nextLine(); System.out.print("Enter new Salary : "); salary = s.nextInt();

li.set(new Employee(empno,ename,salary)); found = true;

}

}

if(!found){

System.out.println("Record Not Found");

}else{

System.out.println("Record is Updated Successfully...!");

}

break;

}

}while(ch!=0);

}

}

9-(2)

Write a program to Sort Array,ArrayList,String,List,Map and Set.

 

package com.company;

import java.util.*; public class Main {

 

public static void main(String[] args) { System.out.println("Array");

int[] arr = {55,69,6,73,8};

Arrays.sort(arr);

System.out.printf("Sorted arr[] = %s",Arrays.toString(arr)); System.out.println("ARRAYLIST");

ArrayList<String>list = new ArrayList<String>(); list.add("sorting");

list.add("java"); list.add("arraylist"); list.add("in");

System.out.println("Unsorted ArrayList: "+ list); Collections.sort(list);

System.out.println("Sorted ArrayList "+ "in Ascending order :"+ list); System.out.println("STRING");

String inputString = "Hello BROS ";

char Array1[] = inputString.toCharArray(); Arrays.sort(Array1);

String outputString =new String(Array1); System.out.println("Input String : " + inputString); System.out.println("Output String : " + outputString); System.out.println("LIST");

Integer[] digits = new Integer[] {15,57,80,25,24,9,89,69,59}; List<Integer> digitsList = Arrays.asList(digits);

 

System.out.println("Unsorted List :"+digitsList); Collections.sort(digitsList); System.out.println("Sorted List :" +digitsList); System.out.println("Map");

HashMap<Integer, String> map = new HashMap<>(); map.put(14, "VEDANT");

map.put(2, "GCET");

map.put(30, "IT");

map.put(5, "12002080501073");

TreeMap<Integer, String> treeMap = new TreeMap<>(map); System.out.println(treeMap);

System.out.println("SET");

HashSet<Integer> numbersSet = new LinkedHashSet<>(Arrays.asList(17,58,89,23,24,8,87,68,39) );

List<Integer> numbersList = new ArrayList<Integer>(numbersSet); Collections.sort(numbersList);

numbersSet = new LinkedHashSet<>(numbersList); System.out.println(numbersSet);

}

}