HR자바 Java Annotations

개요

HR자바 Java Annotations

• https://www.hackerrank.com/challenges/java-annotations/problem

해커랭크 Java

#	문제	비고
HR자바 Advanced e
53	HR자바 Java Varargs - Simple Addition
54	HR자바 Java Reflection - Attributes
55	HR자바 Can You Access?
56	HR자바 Prime Checker
57	HR자바 Java Factory Pattern
58	HR자바 Java Singleton Pattern
59	HR자바 Java Visitor Pattern
60	HR자바 Java Annotations
61	HR자바 Covariant Return Types
62	HR자바 Java Lambda Expressions
63	HR자바 Java MD5
64	HR자바 Java SHA-256

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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() default 0;
}

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 <= budgetLimit) {
                                method.invoke(FamilyMember.class.newInstance(),
                                budgetLimit, spend);
                            } else {
                                System.out.println("Budget Limit Over");
                            }
                        }
                    }
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            testCases--;
        }
    }
}