io.jsonwebtoken.impl.lang

Class Functions

java.lang.Object

io.jsonwebtoken.impl.lang.Functions

public final class Functions
extends Object

Method Summary

Methods

Modifier and Type	Method and Description
static <T,V,R> Function<T,R>	andThen(Function<T,? extends V> before, Function<V,R> after) Returns a composed function that first applies the before function to its input, and then applies the after function to the result.
static <T,R> Function<T,R>	firstResult(Function<T,R>... fns) Returns a composed function that invokes the specified functions in iteration order, and returns the first non-null result.
static <T> Function<T,T>	identity()
static <T,R,E extends RuntimeException> Function<T,R>	wrap(Function<T,R> fn, Class<E> exClass, String fmt, Object... args)
static <T,R,E extends RuntimeException> Function<T,R>	wrapFmt(CheckedFunction<T,R> fn, Class<E> exClass, String msg) Wraps the specified function to ensure that if any exception occurs, it is of the specified type and/or with the specified message.

Methods inherited from class java.lang.Object

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

Method Detail

identity

public static <T> Function<T,T> identity()

wrapFmt

public static <T,R,E extends RuntimeException> Function<T,R> wrapFmt(CheckedFunction<T,R> fn,
                                                     Class<E> exClass,
                                                     String msg)

Wraps the specified function to ensure that if any exception occurs, it is of the specified type and/or with the specified message. If no exception occurs, the function's return value is returned as expected.

If fn throws an exception, its type is checked. If it is already of type exClass, that exception is immediately thrown. If it is not the expected exception type, a message is created with the specified msg template, and a new exception of the specified type is thrown with the formatted message, using the original exception as its cause.

Type Parameters:

T - the function argument type

R - the function's return type

E - type of exception to ensure

Parameters:

fn - the function to execute

exClass - the exception type expected, if any

msg - the formatted message to use if throwing a new exception, used as the first argument to String.format.

Returns:

the wrapping function instance.

wrap

public static <T,R,E extends RuntimeException> Function<T,R> wrap(Function<T,R> fn,
                                                  Class<E> exClass,
                                                  String fmt,
                                                  Object... args)

andThen

public static <T,V,R> Function<T,R> andThen(Function<T,? extends V> before,
                            Function<V,R> after)

Returns a composed function that first applies the before function to its input, and then applies the after function to the result. If evaluation of either function throws an exception, it is relayed to the caller of the composed function.

Type Parameters:

T - type of input to the before function and the resulting composed function.

V - the type of output of the before function, and of the input to the after function.

R - return type of the after function and the resulting composed function.

Parameters:

before - the function to invoke first

after - the function to invoke second with the output from the first

Returns:

a composed function that first applies the before function and then applies the after function.

Throws:

IllegalArgumentException - if either before or after are null.

firstResult

@SafeVarargs
public static <T,R> Function<T,R> firstResult(Function<T,R>... fns)

Returns a composed function that invokes the specified functions in iteration order, and returns the first non-null result. Once a non-null result is discovered, no further functions will be invoked, 'short-circuiting' any remaining functions. If evaluation of any function throws an exception, it is relayed to the caller of the composed function.

Type Parameters:

T - the type of input of the functions, and of the composed function

R - the type of output of the functions, and of the composed function

Parameters:

fns - the functions to iterate

Returns:

a composed function that invokes the specified functions in iteration order, returning the first non-null result.

Throws:

NullPointerException - if after is null