Question

Core_java_threads

The management wants to know the purchase frequency of items that each individual purchases in a shopping. This is helpful analysing the demand for a particular item.

Given a purchase list of items and the list of items whose purchase frequency is to be determined. Can you determine the frequency of each item whose purchase frequency is to be calculated using multi-threading.

Create a class named ItemCount extends Thread class with the following attributes
Public

• String itemName
•     List<String> itemList
•     Integer count

Include appropriate getters and setters.
Include default and parameterized constructor with following order (itemName, itemList).

And also include the following override methods.

No	Method Name	Method Description
1	public void run()	Override the run method, and find the number of purchase for the given item.

Create the class named as Main, which consists a main method read n, the number of purchases and the item names. Also, read the number of items to be searched and read the search items.
Span a thread to calculate the number of purchases for each item.
Once the thread execution is completed, print the items and number of purchases for it, to the console in the main method.

Input Format :

First line of input contains an integer n, the number of purchases.
The next n lines contains strings, the name of the items purchased.
The next n+1 th line contains an integer s, the number of items to be searched.
The next s lines contains strings the items to be searched.

Output Format :
System.out.format("%-5s %-5s\n","Item Name","Count")
Refer to the sample input and output for more details

[Note :Strictly adhere to the object oriented specifications given as a part of the problem statement.Use the same class names, attribute names and method names.]
[All text in bold corresponds to input and the rest corresponds to output]

Sample Input and Output :

Enter the number of purchases
10
Enter the items purchased
Redmi 4
Redmi 4 backcase
Redmi 4
Adidas Neo shoes
Apple iphone 7plus
Adidas Neo shoes
Fossil JR1514 Analog-Digital
Ray ban aviator
Adidas Neo shoes
Ray ban aviator
Number of items to search
2
Apple iphone 7plus
Adidas Neo shoes
Item Name Count
Apple iphone 7plus 1
Adidas Neo shoes 3

Don'ts:
      1. Do not create packages for classes. Strictly adhere to the program structure given in the template code.
      2. Do not use Internet Explorer, highly recommended to use chrome browser to launch ebox platform.
      3. Do not create multiple classes inside a single file. Create separate file for each class.

Main.java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

public class Main {

   public static void main(String[] args) throws IOException, InterruptedException{

       BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
       System.out.println("Enter the number of purchases");
       Integer n = Integer.parseInt(br.readLine());
       List<String> itemList = new ArrayList<String>();
       String item,searchItem;
       System.out.println("Enter the items purchased");
       for(int i=0;i<n;i++){
           item = br.readLine();
           itemList.add(item);
       }
       System.out.println("Number of items to search");
       n = Integer.parseInt(br.readLine());
       List<ItemCount> threadList = new ArrayList<ItemCount>();
       for(int i=0;i<n;i++){
           searchItem = br.readLine();
           threadList.add(new ItemCount(searchItem, itemList));
       }

       //fill in your code here

       System.out.format("%-15s %-15s\n","Item Name","Count");
       for(ItemCount i:threadList){
           System.out.format("%-15s %-15s\n",i.itemName,i.count);
       }
      

   }

}
-----------------------------------

ItemCount.java

import java.util.*;

public class ItemCount //fill in your code here
{
   String itemName;
   List<String> itemList;
   Integer count;
  
   public ItemCount(String itemName,List<String> itemList){
       this.itemName = itemName;
       this.count = 0;
       this.itemList=itemList;
   }
  
   public void run(){

       //fill in your code here

   }

}

Answer 1

Main.java

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.util.ArrayList;

import java.util.List;

public class Main {

   public static void main(String[] args) throws IOException, InterruptedException{

       BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

       System.out.println("Enter the number of purchases");

       Integer n = Integer.parseInt(br.readLine());

       List<String> itemList = new ArrayList<String>();

       String item,searchItem;

       System.out.println("Enter the items purchased");

       for(int i=0;i<n;i++){

           item = br.readLine();

           itemList.add(item);

       }

       System.out.println("Number of items to search");

       n = Integer.parseInt(br.readLine());

       List<ItemCount> threadList = new ArrayList<ItemCount>();

       for(int i=0;i<n;i++){

           searchItem = br.readLine();

           threadList.add(new ItemCount(searchItem, itemList));

       }

       //fill in your code here

       for(ItemCount i:threadList){

           i.start();

           

       }

       System.out.format("%-15s %-15s\n","Item Name","Count");

       for(ItemCount i:threadList){

           System.out.format("%-15s %-15s\n",i.itemName,i.count);

       }

   }

}

-----------------------------------

ItemCount.java

import java.util.*;

public class ItemCount extends Thread //fill in your code here

{

   String itemName;

   List<String> itemList;

   Integer count;

  

   public ItemCount(String itemName,List<String> itemList){

       this.itemName = itemName;

       this.count = 0;

       this.itemList=itemList;

   }

  

   public void run(){

       //fill in your code here

       Iterator iterator = (this.itemList).iterator();

       while (iterator.hasNext()) {

            if(this.itemName.equals(iterator.next()))

                this.count += 1;

       }

    }                                

}

Note 1: Add extends Thread in line number 2 in ItemCount.java file here we inherit the properties of Thread class

Note 2: In line number 14 run method is created which compares the current item to all items for eg if an item is Apple iphone 7plus then it is compared to all 10 items that are present in the list.

Note 3: In Main.java line number 29 we call item.start() method which basically starts the execution of the thread.JVM calls the run() method on the thread.