JThrow

JThrow is a library for exception throwing and logical validation, written in Java

Intro

JThrow is a great tool for exception and test driven development. The main purpose of the library is to encapsulate the inner state of your application, so-called Defensive Programming

Usage

Set up

import jthrow.JThrower;

Code examples

• Intuitive fluent API

String userEmail = "[email protected]";

JThrower.throwIf(userEmail)
    .isNullOrEmpty()
    .has(x -> x.length() < 5 || x.length() > 50)
    .isInvalidEmail();
    

• Descriptive error messages

final int LEGAL_AGE = 18;

public static void buyBeer(int userAge) {
    JThrower.throwIf(userAge, "Age").isLessThan(LEGAL_AGE);
    System.out.println("Beer was sold");
}

public static void main(String[] args) {
    buyBeer(21);
    buyBeer(16);
}

Beer was sold
Exception in thread "main" custom.exceptions.OutOfRangeException: Age cannot be less than 18
	at jthrow/models.ComparableValidationObject.isLessThan(ComparableValidationObject.java:29)
	at jthrow/tests.Test.buyBeer(Test.java:21)
	at jthrow/tests.Test.main(Test.java:17)
    

• All types that implement Comparable are supported

Date minDate = new Date(1890, 1, 1);
Date maxDate = new Date();

Date userBirthdate = new Date(1888, 6, 6);

JThrower.throwIf(userBirthdate)
        .isNull()
        .isOutOfRange(minDate, maxDate);

Exception in thread "main" custom.exceptions.OutOfRangeException: 
Parameter was outside the range [Mon Feb 01 00:00:00 EET 3790, Sun Dec 06 00:54:16 EET 2020]
	at jthrow/models.ComparableValidationObject.isOutOfRange(ComparableValidationObject.java:62)
	at jthrow/tests.Test.main(Test.java:18)
    

License

MIT