Package com.github.m0nk3y2k4.thetvdb.internal.util.validation

Class Preconditions

java.lang.Object

com.github.m0nk3y2k4.thetvdb.internal.util.validation.Preconditions

public final class Preconditions
extends Object

Collection of simple checks to be used to check for method invocation preconditions

The default behavior for precondition checks provided by this class is to throw an APIPreconditionException in case the given arguments do not match the requirements. Some of the methods may support extended control over the actual type of exception that will be thrown by allowing the calling instance to provide it's onw runtime exception instance.

Please note that this class should primarily be used for non-method parameter related precondition/object state checks as the default APIPreconditionException indicates that resolving the failed validation isn't necessarily within the responsibility of the calling instance (although it can be). A common precondition check would be for example to check whether the invoked object is in a proper state in order to process the invocation. If not, this may possibly be resolved by the calling instance by e.g. some additional object initialization. However, it may also prove to be unresolvable for example when the invoked method is only supported for certain object states. To verify the values of given method parameters use Parameters.

Method Summary

Modifier and Type	Method	Description
static void	requireNonEmpty(String obj, String message)	Checks that the given String is neither null nor empty.
static void	requireNonNull(Object obj, String message)	Checks that the given obj is not null.
static <T,X extends RuntimeException> void	requires(Predicate<T> condition, T value, X exception)	Checks the condition and throws the given runtime exception in case the condition is not met.

Methods inherited from class java.lang.Object

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

Method Detail

requires

public static <T,X extends RuntimeException> void requires(Predicate<T> condition,
                                                           T value,
                                                           X exception)

Checks the condition and throws the given runtime exception in case the condition is not met.

Type Parameters:

T - the type of the value to check

X - type of the runtime exception to be thrown

Parameters:

condition - The condition to check for

value - The value to check against the condition

exception - The exception to be thrown in case the condition is not met

requireNonNull

public static void requireNonNull(Object obj,
                                  String message)

Checks that the given obj is not null. Otherwise an exception with the given error message will be thrown.

Parameters:

obj - The object to check

message - Error message to be propagated to the exception in case of a failed validation

Throws:

APIPreconditionException - If the given obj is null

requireNonEmpty

public static void requireNonEmpty(String obj,
                                   String message)

Checks that the given String is neither null nor empty. Otherwise an exception with the given error message will be thrown.

Parameters:

obj - The String to check

message - Error message to be propagated to the exception in case of a failed validation

Throws:

APIPreconditionException - If the given String is either null or empty