Package org.eclipse.jetty.io.content

Class ContentSourceCompletableFuture<X>

java.lang.Object

java.util.concurrent.CompletableFuture<X>

org.eclipse.jetty.io.content.ContentSourceCompletableFuture<X>

All Implemented Interfaces:

CompletionStage<X>, Future<X>

Direct Known Subclasses:

FormFields

public abstract class ContentSourceCompletableFuture<X>
extends CompletableFuture<X>

A utility class to convert content from a Content.Source to an instance available via a CompletableFuture.

An example usage to asynchronously read UTF-8 content is:

 public static class CompletableUTF8String extends ContentSourceCompletableFuture<String>;
 {
     private final Utf8StringBuilder builder = new Utf8StringBuilder();

     public CompletableUTF8String(Content.Source content)
     {
         super(content);
     }

     @Override
     protected String parse(Content.Chunk chunk) throws Throwable
     {
         // Accumulate the chunk bytes.
         if (chunk.hasRemaining())
             builder.append(chunk.getByteBuffer());

         // Not the last chunk, the result is not ready yet.
         if (!chunk.isLast())
             return null;

         // The result is ready.
         return builder.takeCompleteString(IllegalStateException::new);
     }
 }
 
 CompletableUTF8String cs = new CompletableUTF8String(source);
 cs.parse();
 String s = cs.get();
 

Nested Class Summary

Nested classes/interfaces inherited from class java.util.concurrent.CompletableFuture

CompletableFuture.AsynchronousCompletionTask

Constructor Summary

Constructors

Constructor	Description
ContentSourceCompletableFuture(Content.Source content)

Method Summary

Modifier and Type	Method	Description
protected boolean	onTransientFailure(Throwable cause)	Callback method that informs the parsing about how to handle transient failures.
void	parse()	Initiates the parsing of the Content.Source.
protected abstract X	parse(Content.Chunk chunk)	Called by parse() to parse a Content.Chunk.

Methods inherited from class java.util.concurrent.CompletableFuture

acceptEither, acceptEitherAsync, acceptEitherAsync, allOf, anyOf, applyToEither, applyToEitherAsync, applyToEitherAsync, cancel, complete, completeAsync, completeAsync, completedFuture, completedStage, completeExceptionally, completeOnTimeout, copy, defaultExecutor, delayedExecutor, delayedExecutor, exceptionally, exceptionallyAsync, exceptionallyAsync, exceptionallyCompose, exceptionallyComposeAsync, exceptionallyComposeAsync, failedFuture, failedStage, get, get, getNow, getNumberOfDependents, handle, handleAsync, handleAsync, isCancelled, isCompletedExceptionally, isDone, join, minimalCompletionStage, newIncompleteFuture, obtrudeException, obtrudeValue, orTimeout, runAfterBoth, runAfterBothAsync, runAfterBothAsync, runAfterEither, runAfterEitherAsync, runAfterEitherAsync, runAsync, runAsync, supplyAsync, supplyAsync, thenAccept, thenAcceptAsync, thenAcceptAsync, thenAcceptBoth, thenAcceptBothAsync, thenAcceptBothAsync, thenApply, thenApplyAsync, thenApplyAsync, thenCombine, thenCombineAsync, thenCombineAsync, thenCompose, thenComposeAsync, thenComposeAsync, thenRun, thenRunAsync, thenRunAsync, toCompletableFuture, toString, whenComplete, whenCompleteAsync, whenCompleteAsync

Methods inherited from class java.lang.Object

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

Constructor Details

ContentSourceCompletableFuture

public ContentSourceCompletableFuture(Content.Source content)

Method Details

parse

public void parse()

Initiates the parsing of the Content.Source.

For every valid chunk that is read, parse(Content.Chunk) is called, until a result is produced that is used to complete this CompletableFuture.

Internally, this method is called multiple times to progress the parsing in response to Content.Source.demand(Runnable) calls.

Exceptions thrown during parsing result in this CompletableFuture to be completed exceptionally.

parse

protected abstract X parse(Content.Chunk chunk)
                    throws Throwable

Called by parse() to parse a Content.Chunk.

Parameters:

chunk - The chunk containing content to parse. The chunk will never be null nor a failure chunk. If the chunk is stored away to be used later beyond the scope of this call, then implementations must call Retainable.retain() and Retainable.release() as appropriate.

Returns:

The parsed X result instance or null if parsing is not yet complete

Throws:

Throwable - If there is an error parsing

onTransientFailure

protected boolean onTransientFailure(Throwable cause)

Callback method that informs the parsing about how to handle transient failures.

Parameters:

cause - A transient failure obtained by reading a non-last failure chunk

Returns:

true if the transient failure can be ignored, false otherwise