Package net.openid.appauth

Class Preconditions

java.lang.Object

net.openid.appauth.Preconditions

public final class Preconditions
extends Object

Utility class for guava style pre-condition checks.

Not an official part of the AppAuth API; only intended for internal use and no guarantees are given on source or binary compatibility for this class between versions of AppAuth.

Method Summary

Modifier and Type	Method	Description
static void	checkArgument(boolean expression)	Ensures the truth of an expression involving one or more parameters to the calling method.
static void	checkArgument(boolean expression, Object errorMessage)	Ensures the truth of an expression involving one or more parameters to the calling method.
static void	checkArgument(boolean expression, String errorTemplate, Object... params)	Ensures the truth of an expression involving one or more parameters to the calling method.
static <T extends Collection<?>> T	checkCollectionNotEmpty(T collection, Object errorMessage)	Ensures that a collection is not null or empty.
static String	checkNotEmpty(String str, Object errorMessage)	Ensures that a string is not null or empty.
static <T> T	checkNotNull(T reference)	Ensures that an object reference passed as a parameter to the calling method is not null.
static <T> T	checkNotNull(T reference, Object errorMessage)	Ensures that an object reference passed as a parameter to the calling method is not null.
static String	checkNullOrNotEmpty(String str, Object errorMessage)	Ensures that the string is either null, or a non-empty string.

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)

Ensures that an object reference passed as a parameter to the calling method is not null.

Parameters:

reference - an object reference

Returns:

the non-null reference that was validated

Throws:

NullPointerException - if reference is null

checkNotNull

public static <T> T checkNotNull(T reference,
                                 @Nullable
                                 Object errorMessage)

Ensures that an object reference passed as a parameter to the calling method is not null.

Parameters:

reference - an object reference

errorMessage - the exception message to use if the check fails; will be converted to a string using String.valueOf(Object)

Returns:

the non-null reference that was validated

Throws:

NullPointerException - if reference is null

checkNotEmpty

@NonNull
public static String checkNotEmpty(String str,
                                   @Nullable
                                   Object errorMessage)

Ensures that a string is not null or empty.

checkCollectionNotEmpty

@NonNull
public static <T extends Collection<?>> T checkCollectionNotEmpty(T collection,
                                                                  @Nullable
                                                                  Object errorMessage)

Ensures that a collection is not null or empty.

checkNullOrNotEmpty

@NonNull
public static String checkNullOrNotEmpty(String str,
                                         @Nullable
                                         Object errorMessage)

Ensures that the string is either null, or a non-empty string.

checkArgument

public static void checkArgument(boolean expression)

Ensures the truth of an expression involving one or more parameters to the calling method.

Parameters:

expression - a boolean expression

Throws:

IllegalArgumentException - if expression is false

checkArgument

public static void checkArgument(boolean expression,
                                 @Nullable
                                 Object errorMessage)

Ensures the truth of an expression involving one or more parameters to the calling method.

Parameters:

expression - a boolean expression

errorMessage - the exception message to use if the check fails; will be converted to a string using String.valueOf(Object)

Throws:

IllegalArgumentException - if expression is false

checkArgument

public static void checkArgument(boolean expression,
                                 @NonNull
                                 String errorTemplate,
                                 Object... params)

Ensures the truth of an expression involving one or more parameters to the calling method.

Parameters:

expression - a boolean expression

errorTemplate - the exception message to use if the check fails; this is used as the template for String.format.

params - the parameters to the exception message.