Java Annotations with Explanation

10 Apr Java Annotations with Explanation

Hello Friends, How are you? Today I will solve the HackerRank Java Annotations – Problem with a straightforward explanation. In this article, you will get more than one approach to solve this problem. So let’s start- {tocify} $title={Table of Contents}  Java annotation can be used to define the metadata of a Java class or class element. We can use Java annotation at the compile time to instruct the compiler about the build process. Annotation is also used at runtime to get insight into the properties of class elements. Here, we partially define an annotation, FamilyBudget and a class, FamilyMember. In this problem, we give the user role and the amount of money that a user spends as input. Based on the user role, you have to call the appropriate method in the FamilyMember class. If the amount of money spent is over the budget limit for that user role, it prints Budget Limit Over. Your task is to complete the FamilyBudget annotation and the FamilyMember class so that the Solution class works perfectly with the defined constraints. Note: You must complete the 5 incomplete lines in the editor. You are not allowed to change, delete or modify any other lines. To restore the original code, click on the top-left button on the editor and create a new buffer. The first line of input contains an integer N  representing the total number of test cases. Each test case contains a string and an integer separated by a space on a single line in the following format:

UserRole MoneySpend {codeBox}

The name contains only lowercase English Letters. Based on the user role and budget outputs, output the contents of the certain method. If the amount of money spent is over the budget limit, then output Budget Limit Over.

3 SENIOR 75 JUNIOR 45 SENIOR 40 {codeBox}

Senior Member Spend: 75 Budget Left: 25 Junior Member Spend: 45 Budget Left: 5 Senior Member Spend: 40 Budget Left: 60 {codeBox}

Java Annotations HackerRank Solution Approach I: Java Annotations – Solution HackerRank

// ========================
// Information
// ======================== // Name: Java Annotations HackerRank Problem
// Direct Link: https://www.hackerrank.com/challenges/java-annotations/problem
// Difficulty: Medium
// Max Score: 25
// Language: Java 8 // ========================
// Solution Start
// ======================== // Java Annotations - Hacker Rank Solution Start import java.lang.annotation.*;
import java.lang.reflect.*;
import java.util.*; @Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@interface FamilyBudget { String userRole() default "GUEST"; int budgetLimit();
} class FamilyMember { @FamilyBudget(userRole = "SENIOR", budgetLimit = 100) public void seniorMember(int budget, int moneySpend) { System.out.println("Senior Member"); System.out.println("Spend: " + moneySpend); System.out.println("Budget Left: " + (budget - moneySpend)); } @FamilyBudget(userRole = "JUNIOR", budgetLimit = 50) public void juniorUser(int budget, int moneySpend) { System.out.println("Junior Member"); System.out.println("Spend: " + moneySpend); System.out.println("Budget Left: " + (budget - moneySpend)); }
} public class Solution { public static void main(String[] args) { Scanner in = new Scanner(System.in); int testCases = Integer.parseInt(in.nextLine()); while (testCases > 0) { String role = in.next(); int spend = in.nextInt(); try { Class annotatedClass = FamilyMember.class; Method[] methods = annotatedClass.getMethods(); for (Method method : methods) { if (method.isAnnotationPresent(FamilyBudget.class)) { FamilyBudget family = method .getAnnotation(FamilyBudget.class); String userRole = family.userRole(); int budgetLimit = family.budgetLimit(); if (userRole.equals(role)) { if(spend