Package io.helidon.config

Class ConfigHelper

java.lang.Object

io.helidon.config.ConfigHelper

public final class ConfigHelper
extends Object

Common Configuration utilities.

Method Summary

Modifier and Type	Method and Description
static Reader	createReader(Readable readable) Creates a Reader from the given Readable object.
static String	detectContentType(Path path) Infers the content type contained in the provided Path.
static <T> Flow.Subscriber<T>	subscriber(Function<T,Boolean> onNextFunction) Creates a Flow.Subscriber that will delegate Flow.Subscriber#onNext(Object) to the specified onNextFunction function.
static <T> Flow.Publisher<T>	suspendablePublisher(Flow.Publisher<T> delegatePublisher, Runnable onFirstSubscriptionRequest, Runnable onLastSubscriptionCancel) Creates a Flow.Publisher which wraps the provided one and also supports "active" and "suspended" states.

Methods inherited from class java.lang.Object

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

Method Detail

createReader

public static Reader createReader(Readable readable)
                           throws IOException

Creates a Reader from the given Readable object.

Equivalent to createReader(readable, 1024). See createReader(Readable,int).

Parameters:

readable - a readable

Returns:

a reader

Throws:

IOException - when Readable.read(CharBuffer) encounters an error

subscriber

public static <T> Flow.Subscriber<T> subscriber(Function<T,Boolean> onNextFunction)

Creates a Flow.Subscriber that will delegate Flow.Subscriber#onNext(Object) to the specified onNextFunction function.

The new subscriber's Flow.Subscriber#onSubscribe(Flow.Subscription) method automatically invokes Flow.Subscription#request(long) to request all events that are available in the subscription.

The caller-provided onNextFunction should return false in order to cancel current subscription.

Type Parameters:

T - the type of the items provided by the subscription

Parameters:

onNextFunction - function to be invoked during onNext processing

Returns:

Subscriber that delegates its onNext to the caller-provided function

suspendablePublisher

public static <T> Flow.Publisher<T> suspendablePublisher(Flow.Publisher<T> delegatePublisher,
                                                         Runnable onFirstSubscriptionRequest,
                                                         Runnable onLastSubscriptionCancel)

Creates a Flow.Publisher which wraps the provided one and also supports "active" and "suspended" states.

The new Publisher starts in the "suspended" state. Upon the first subscriber request the Publisher transitions into the "active" state and invokes the caller-supplied onFirstSubscriptionRequest Runnable. When the last subscriber cancels the returned Publisher transitions into the "suspended" state and invokes the caller-provided onLastSubscriptionCancel Runnable.

Type Parameters:

T - the type of the items provided by the publisher

Parameters:

delegatePublisher - publisher to be wrapped

onFirstSubscriptionRequest - hook invoked when the first subscriber requests events from the publisher

onLastSubscriptionCancel - hook invoked when last remaining subscriber cancels its subscription

Returns:

new instance of suspendable Flow.Publisher

detectContentType

public static String detectContentType(Path path)

Infers the content type contained in the provided Path.

Parameters:

path - path to check

Returns:

string with content type