almost.functional.utils

Class Preconditions

java.lang.Object

almost.functional.utils.Preconditions

public final class Preconditions
extends java.lang.Object

Utility operations designed to be used as precondition tests.

Method Summary

Methods

Modifier and Type	Method and Description
static java.lang.String	checkNonEmptyString(java.lang.String reference, java.lang.String errorMessage) Check that a String is not empty after removing whitespace.
static <T> T	checkNotNull(T reference, java.lang.String errorMessage) Check that a reference is not null, throwing a IllegalArgumentException if it is.
static java.lang.Class	isAssignableTo(java.lang.Class<?> fromValue, java.lang.Class<?> toValue, java.lang.String message) Check that one class is assignable to another.

Methods inherited from class java.lang.Object

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

Method Detail

checkNotNull

public static <T> T checkNotNull(T reference,
                 java.lang.String errorMessage)

Check that a reference is not null, throwing a IllegalArgumentException if it is.

Type Parameters:

T - the type of the reference

Parameters:

reference - The reference to check

errorMessage - the message for the exception if the reference is null

Throws:

java.lang.IllegalArgumentException - if the reference is null

checkNonEmptyString

public static java.lang.String checkNonEmptyString(java.lang.String reference,
                                   java.lang.String errorMessage)

Check that a String is not empty after removing whitespace.

Parameters:

reference - the string

errorMessage - the message for the exception

Throws:

java.lang.NullPointerException - if the String is null

java.lang.IllegalArgumentException - if the string is non-null but zero length

isAssignableTo

public static java.lang.Class isAssignableTo(java.lang.Class<?> fromValue,
                             java.lang.Class<?> toValue,
                             java.lang.String message)

Check that one class is assignable to another.

Parameters:

fromValue - the class assigning from

toValue - the class assigning to

message - the message used in the exception if thrown

Throws:

java.lang.ClassCastException - if the assignment can not be made