Get the enum constant by name ignoring case

Write a generic method that takes a enum name as input and return an enumeration constant that matches the string without being case sensitive.

 

Signature

public static <T extends Enum<T>> T byNameInsensitiveCase(final Class<T> enumType, final String name)

 

An enum constant in Java is a special type of variable that represents a fixed set of values. Enum constants are declared within an enum type and can be used to define named constants for a specific type or category.

 

Use Cases of Enum Constants:

1.   Representing Predefined Values: Enum constants are often used to define a fixed set of options or states within an application. For example, days of the week, months of the year, colors, etc.

2.   Type Safety: Enums provide type safety, ensuring that only valid values can be assigned to variables of that type.

3.   Switch Statements: Enums are commonly used in switch statements to handle multiple cases elegantly.

4.   Configuration Options: Enums can be used to represent configuration options or settings in applications.

5.   State Machines: Enum constants are useful for defining states in finite state machines, making state transitions clearer and more manageable.

 

Find the below working application.

 

EnumUtils.java

package com.sample.util;

public class EnumUtils {

	/**
	 * 
	 * @param <T>
	 * @param enumClazz - Enum class object
	 * @param name      - name of the enum constant
	 * @return the enum constant that matches to given name. Throws
	 *         {@link IllegalArgumentException} if no enum matches to the given
	 *         name.
	 */
	public static <T extends Enum<T>> T byNameInsensitiveCase(final Class<T> enumClazz, final String name) {
		if (name == null || name.isEmpty()) {
			throw new IllegalArgumentException("name can't be null");
		}

		for (T enumConstant : enumClazz.getEnumConstants()) {
			if (enumConstant.name().compareToIgnoreCase(name) == 0) {
				return enumConstant;
			}
		}
		throw new IllegalArgumentException("No enum constant found for given name : " + name);
	}

}

EnumByNameDemo.java

package com.sample.app;

import com.sample.util.EnumUtils;

public class EnumByNameDemo {

	private static enum Month {
		JANUARY(1, "31 Days"), FEBRUARY(2, "28 or 29 Days"), MARCH(3, "31 Days"), APRIL(4, "30 days"),
		MAY(5, "31 Days"), JUNE(6, "30 Days"), JULY(7, "31 Days"), AUGUST(8, "31 Days"), SEPTEMBER(9, "30 Days"),
		OCTOBER(10, "31 Days"), NOVEMBER(11, "30 Days"), DECEMBER(12, "31 Days");

		int num;
		String msg;

		Month(int num, String msg) {
			this.num = num;
			this.msg = msg;
		}

		public String toString() {
			return this.name() + " is the " + num + " month and has " + msg;
		}

	}

	public static void main(String[] args) {
		Month month = EnumUtils.byNameInsensitiveCase(Month.class, "auGUst");

		System.out.println(month);

	}

}

Output

AUGUST is the 8 month and has 31 Days

 

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