revxrsal.commands.util

Class Preconditions

java.lang.Object

revxrsal.commands.util.Preconditions

public final class Preconditions
extends java.lang.Object

A utility class to check for preconditions of functions, allowing to catch problematic user input early on.

Method Summary

Modifier and Type	Method and Description
static void	cannotInstantiate(java.lang.Class<?> clazz) Throws an exception that the user cannot instantiate the given class
static <T> void	notEmpty(T[] array, java.lang.String errorMessage) Ensures that the given array is not empty
static <T> T	notNull(T t, java.lang.String err) Checks that the specified object reference is not null.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

notEmpty

public static <T> void notEmpty(T[] array,
                                java.lang.String errorMessage)

Ensures that the given array is not empty

Type Parameters:

T - The array type

Parameters:

array - Array to check

errorMessage - Error message to throw with

notNull

@Contract(value="null, _ -> fail; !null, _ -> param1")
public static <T> T notNull(T t,
                                                                                   java.lang.String err)

Checks that the specified object reference is not null. This will automatically append cannot be null! to the error message.

Type Parameters:

T - The object type

Parameters:

t - Object to check

err - Error message.

Returns:

The same object

cannotInstantiate

@Contract(value="_ -> fail")
public static void cannotInstantiate(java.lang.Class<?> clazz)

Throws an exception that the user cannot instantiate the given class

Parameters:

clazz - Class to prevent instantiating