test/jdk/java/net/httpclient/HttpInputStreamTest.java - platform/libcore - Git at Google

 /*
  * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */

 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.Reader;
 import java.net.URI;
 import java.net.http.HttpClient;
 import java.net.http.HttpHeaders;
 import java.net.http.HttpRequest;
 import java.net.http.HttpResponse;
 import java.nio.ByteBuffer;
 import java.nio.charset.Charset;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Locale;
 import java.util.Optional;
 import java.util.concurrent.ArrayBlockingQueue;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.CompletionStage;
 import java.util.concurrent.Flow;
 import java.util.stream.Stream;
 import static java.lang.System.err;

 /*
  * @test
  * @summary An example on how to read a response body with InputStream.
  * @run main/othervm/manual -Dtest.debug=true HttpInputStreamTest
  * @author daniel fuchs
  */
 public class HttpInputStreamTest {

     public static boolean DEBUG = Boolean.getBoolean("test.debug");

     /**
      * A simple HttpResponse.BodyHandler that creates a live
      * InputStream to read the response body from the underlying ByteBuffer
      * Flow.
      * The InputStream is made immediately available for consumption, before
      * the response body is fully received.
      */
     public static class HttpInputStreamHandler
         implements HttpResponse.BodyHandler<InputStream>    {

         public static final int MAX_BUFFERS_IN_QUEUE = 1;  // lock-step with the producer

         private final int maxBuffers;

         public HttpInputStreamHandler() {
             this(MAX_BUFFERS_IN_QUEUE);
         }

         public HttpInputStreamHandler(int maxBuffers) {
             this.maxBuffers = maxBuffers <= 0 ? MAX_BUFFERS_IN_QUEUE : maxBuffers;
         }

         @Override
         public HttpResponse.BodySubscriber<InputStream>
                 apply(HttpResponse.ResponseInfo rinfo) {
             return new HttpResponseInputStream(maxBuffers);
         }

         /**
          * An InputStream built on top of the Flow API.
          */
         private static class HttpResponseInputStream extends InputStream
                     implements HttpResponse.BodySubscriber<InputStream> {

             // An immutable ByteBuffer sentinel to mark that the last byte was received.
             private static final ByteBuffer LAST_BUFFER = ByteBuffer.wrap(new byte[0]);
             private static final List<ByteBuffer> LAST_LIST = List.of(LAST_BUFFER);

             // A queue of yet unprocessed ByteBuffers received from the flow API.
             private final BlockingQueue<List<ByteBuffer>> buffers;
             private volatile Flow.Subscription subscription;
             private volatile boolean closed;
             private volatile Throwable failed;
             private volatile Iterator<ByteBuffer> currentListItr;
             private volatile ByteBuffer currentBuffer;

             HttpResponseInputStream() {
                 this(MAX_BUFFERS_IN_QUEUE);
             }

             HttpResponseInputStream(int maxBuffers) {
                 int capacity = maxBuffers <= 0 ? MAX_BUFFERS_IN_QUEUE : maxBuffers;
                 // 1 additional slot for LAST_LIST added by onComplete
                 this.buffers = new ArrayBlockingQueue<>(capacity + 1);
             }

             @Override
             public CompletionStage<InputStream> getBody() {
                 // Return the stream immediately, before the
                 // response body is received.
                 // This makes it possible for senAsync().get().body()
                 // to complete before the response body is received.
                 return CompletableFuture.completedStage(this);
             }

             // Returns the current byte buffer to read from.
             // If the current buffer has no remaining data, will take the
             // next buffer from the buffers queue, possibly blocking until
             // a new buffer is made available through the Flow API, or the
             // end of the flow is reached.
             private ByteBuffer current() throws IOException {
                 while (currentBuffer == null || !currentBuffer.hasRemaining()) {
                     // Check whether the stream is closed or exhausted
                     if (closed || failed != null) {
                         throw new IOException("closed", failed);
                     }
                     if (currentBuffer == LAST_BUFFER) break;

                     try {
                         if (currentListItr == null || !currentListItr.hasNext()) {
                             // Take a new list of buffers from the queue, blocking
                             // if none is available yet...

                             if (DEBUG) err.println("Taking list of Buffers");
                             List<ByteBuffer> lb = buffers.take();
                             currentListItr = lb.iterator();
                             if (DEBUG) err.println("List of Buffers Taken");

                             // Check whether an exception was encountered upstream
                             if (closed || failed != null)
                                 throw new IOException("closed", failed);

                             // Check whether we're done.
                             if (lb == LAST_LIST) {
                                 currentListItr = null;
                                 currentBuffer = LAST_BUFFER;
                                 break;
                             }

                             // Request another upstream item ( list of buffers )
                             Flow.Subscription s = subscription;
                             if (s != null)
                                 s.request(1);
                         }
                         assert currentListItr != null;
                         assert currentListItr.hasNext();
                         if (DEBUG) err.println("Next Buffer");
                         currentBuffer = currentListItr.next();
                     } catch (InterruptedException ex) {
                         // continue
                     }
                 }
                 assert currentBuffer == LAST_BUFFER || currentBuffer.hasRemaining();
                 return currentBuffer;
             }

             @Override
             public int read(byte[] bytes, int off, int len) throws IOException {
                 // get the buffer to read from, possibly blocking if
                 // none is available
                 ByteBuffer buffer;
                 if ((buffer = current()) == LAST_BUFFER) return -1;

                 // don't attempt to read more than what is available
                 // in the current buffer.
                 int read = Math.min(buffer.remaining(), len);
                 assert read > 0 && read <= buffer.remaining();

                 // buffer.get() will do the boundary check for us.
                 buffer.get(bytes, off, read);
                 return read;
             }

             @Override
             public int read() throws IOException {
                 ByteBuffer buffer;
                 if ((buffer = current()) == LAST_BUFFER) return -1;
                 return buffer.get() & 0xFF;
             }

             @Override
             public void onSubscribe(Flow.Subscription s) {
                 if (this.subscription != null) {
                     s.cancel();
                     return;
                 }
                 this.subscription = s;
                 assert buffers.remainingCapacity() > 1; // should at least be 2
                 if (DEBUG) err.println("onSubscribe: requesting "
                      + Math.max(1, buffers.remainingCapacity() - 1));
                 s.request(Math.max(1, buffers.remainingCapacity() - 1));
             }

             @Override
             public void onNext(List<ByteBuffer> t) {
                 try {
                     if (DEBUG) err.println("next item received");
                     if (!buffers.offer(t)) {
                         throw new IllegalStateException("queue is full");
                     }
                     if (DEBUG) err.println("item offered");
                 } catch (Exception ex) {
                     failed = ex;
                     try {
                         close();
                     } catch (IOException ex1) {
                         // OK
                     }
                 }
             }

             @Override
             public void onError(Throwable thrwbl) {
                 subscription = null;
                 failed = thrwbl;
             }

             @Override
             public void onComplete() {
                 subscription = null;
                 onNext(LAST_LIST);
             }

             @Override
             public void close() throws IOException {
                 synchronized (this) {
                     if (closed) return;
                     closed = true;
                 }
                 Flow.Subscription s = subscription;
                 subscription = null;
                 if (s != null) {
                      s.cancel();
                 }
                 super.close();
             }

         }
     }

     /**
      * Examine the response headers to figure out the charset used to
      * encode the body content.
      * If the content type is not textual, returns an empty Optional.
      * Otherwise, returns the body content's charset, defaulting to
      * ISO-8859-1 if none is explicitly specified.
      * @param headers The response headers.
      * @return The charset to use for decoding the response body, if
      *         the response body content is text/...
      */
     public static Optional<Charset> getCharset(HttpHeaders headers) {
         Optional<String> contentType = headers.firstValue("Content-Type");
         Optional<Charset> charset = Optional.empty();
         if (contentType.isPresent()) {
             final String[] values = contentType.get().split(";");
             if (values[0].startsWith("text/")) {
                 charset = Optional.of(Stream.of(values)
                     .map(x -> x.toLowerCase(Locale.ROOT))
                     .map(String::trim)
                     .filter(x -> x.startsWith("charset="))
                     .map(x -> x.substring("charset=".length()))
                     .findFirst()
                     .orElse("ISO-8859-1"))
                     .map(Charset::forName);
             }
         }
         return charset;
     }

     public static void main(String[] args) throws Exception {
         HttpClient client = HttpClient.newHttpClient();
         HttpRequest request = HttpRequest
             .newBuilder(new URI("http://hg.openjdk.java.net/jdk9/sandbox/jdk/shortlog/http-client-branch/"))
             .GET()
             .build();

         // This example shows how to return an InputStream that can be used to
         // start reading the response body before the response is fully received.
         // In comparison, the snipet below (which uses
         // HttpResponse.BodyHandlers.ofString()) obviously will not return before the
         // response body is fully read:
         //
         // System.out.println(
         //    client.sendAsync(request, HttpResponse.BodyHandlers.ofString()).get().body());

         CompletableFuture<HttpResponse<InputStream>> handle =
             client.sendAsync(request, new HttpInputStreamHandler(3));
         if (DEBUG) err.println("Request sent");

         HttpResponse<InputStream> pending = handle.get();

         // At this point, the response headers have been received, but the
         // response body may not have arrived yet. This comes from
         // the implementation of HttpResponseInputStream::getBody above,
         // which returns an already completed completion stage, without
         // waiting for any data.
         // We can therefore access the headers - and the body, which
         // is our live InputStream, without waiting...
         HttpHeaders responseHeaders = pending.headers();

         // Get the charset declared in the response headers.
         // The optional will be empty if the content type is not
         // of type text/...
         Optional<Charset> charset = getCharset(responseHeaders);

         try (InputStream is = pending.body();
             // We assume a textual content type. Construct an InputStream
             // Reader with the appropriate Charset.
             // charset.get() will throw NPE if the content is not textual.
             Reader r = new InputStreamReader(is, charset.get())) {

             char[] buff = new char[32];
             int off=0, n=0;
             if (DEBUG) err.println("Start receiving response body");
             if (DEBUG) err.println("Charset: " + charset.get());

             // Start consuming the InputStream as the data arrives.
             // Will block until there is something to read...
             while ((n = r.read(buff, off, buff.length - off)) > 0) {
                 assert (buff.length - off) > 0;
                 assert n <= (buff.length - off);
                 if (n == (buff.length - off)) {
                     System.out.print(buff);
                     off = 0;
                 } else {
                     off += n;
                 }
                 assert off < buff.length;
             }

             // last call to read may not have filled 'buff' completely.
             // flush out the remaining characters.
             assert off >= 0 && off < buff.length;
             for (int i=0; i < off; i++) {
                 System.out.print(buff[i]);
             }

             // We're done!
             System.out.println("Done!");
         }
     }

 }
	/*
	* Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	import java.io.IOException;
	import java.io.InputStream;
	import java.io.InputStreamReader;
	import java.io.Reader;
	import java.net.URI;
	import java.net.http.HttpClient;
	import java.net.http.HttpHeaders;
	import java.net.http.HttpRequest;
	import java.net.http.HttpResponse;
	import java.nio.ByteBuffer;
	import java.nio.charset.Charset;
	import java.util.Iterator;
	import java.util.List;
	import java.util.Locale;
	import java.util.Optional;
	import java.util.concurrent.ArrayBlockingQueue;
	import java.util.concurrent.BlockingQueue;
	import java.util.concurrent.CompletableFuture;
	import java.util.concurrent.CompletionStage;
	import java.util.concurrent.Flow;
	import java.util.stream.Stream;
	import static java.lang.System.err;

	/*
	* @test
	* @summary An example on how to read a response body with InputStream.
	* @run main/othervm/manual -Dtest.debug=true HttpInputStreamTest
	* @author daniel fuchs
	*/
	public class HttpInputStreamTest {

	public static boolean DEBUG = Boolean.getBoolean("test.debug");

	/**
	* A simple HttpResponse.BodyHandler that creates a live
	* InputStream to read the response body from the underlying ByteBuffer
	* Flow.
	* The InputStream is made immediately available for consumption, before
	* the response body is fully received.
	*/
	public static class HttpInputStreamHandler
	implements HttpResponse.BodyHandler<InputStream> {

	public static final int MAX_BUFFERS_IN_QUEUE = 1; // lock-step with the producer

	private final int maxBuffers;

	public HttpInputStreamHandler() {
	this(MAX_BUFFERS_IN_QUEUE);
	}

	public HttpInputStreamHandler(int maxBuffers) {
	this.maxBuffers = maxBuffers <= 0 ? MAX_BUFFERS_IN_QUEUE : maxBuffers;
	}

	@Override
	public HttpResponse.BodySubscriber<InputStream>
	apply(HttpResponse.ResponseInfo rinfo) {
	return new HttpResponseInputStream(maxBuffers);
	}

	/**
	* An InputStream built on top of the Flow API.
	*/
	private static class HttpResponseInputStream extends InputStream
	implements HttpResponse.BodySubscriber<InputStream> {

	// An immutable ByteBuffer sentinel to mark that the last byte was received.
	private static final ByteBuffer LAST_BUFFER = ByteBuffer.wrap(new byte[0]);
	private static final List<ByteBuffer> LAST_LIST = List.of(LAST_BUFFER);

	// A queue of yet unprocessed ByteBuffers received from the flow API.
	private final BlockingQueue<List<ByteBuffer>> buffers;
	private volatile Flow.Subscription subscription;
	private volatile boolean closed;
	private volatile Throwable failed;
	private volatile Iterator<ByteBuffer> currentListItr;
	private volatile ByteBuffer currentBuffer;

	HttpResponseInputStream() {
	this(MAX_BUFFERS_IN_QUEUE);
	}

	HttpResponseInputStream(int maxBuffers) {
	int capacity = maxBuffers <= 0 ? MAX_BUFFERS_IN_QUEUE : maxBuffers;
	// 1 additional slot for LAST_LIST added by onComplete
	this.buffers = new ArrayBlockingQueue<>(capacity + 1);
	}

	@Override
	public CompletionStage<InputStream> getBody() {
	// Return the stream immediately, before the
	// response body is received.
	// This makes it possible for senAsync().get().body()
	// to complete before the response body is received.
	return CompletableFuture.completedStage(this);
	}

	// Returns the current byte buffer to read from.
	// If the current buffer has no remaining data, will take the
	// next buffer from the buffers queue, possibly blocking until
	// a new buffer is made available through the Flow API, or the
	// end of the flow is reached.
	private ByteBuffer current() throws IOException {
	while (currentBuffer == null \|\| !currentBuffer.hasRemaining()) {
	// Check whether the stream is closed or exhausted
	if (closed \|\| failed != null) {
	throw new IOException("closed", failed);
	}
	if (currentBuffer == LAST_BUFFER) break;

	try {
	if (currentListItr == null \|\| !currentListItr.hasNext()) {
	// Take a new list of buffers from the queue, blocking
	// if none is available yet...

	if (DEBUG) err.println("Taking list of Buffers");
	List<ByteBuffer> lb = buffers.take();
	currentListItr = lb.iterator();
	if (DEBUG) err.println("List of Buffers Taken");

	// Check whether an exception was encountered upstream
	if (closed \|\| failed != null)
	throw new IOException("closed", failed);

	// Check whether we're done.
	if (lb == LAST_LIST) {
	currentListItr = null;
	currentBuffer = LAST_BUFFER;
	break;
	}

	// Request another upstream item ( list of buffers )
	Flow.Subscription s = subscription;
	if (s != null)
	s.request(1);
	}
	assert currentListItr != null;
	assert currentListItr.hasNext();
	if (DEBUG) err.println("Next Buffer");
	currentBuffer = currentListItr.next();
	} catch (InterruptedException ex) {
	// continue
	}
	}
	assert currentBuffer == LAST_BUFFER \|\| currentBuffer.hasRemaining();
	return currentBuffer;
	}

	@Override
	public int read(byte[] bytes, int off, int len) throws IOException {
	// get the buffer to read from, possibly blocking if
	// none is available
	ByteBuffer buffer;
	if ((buffer = current()) == LAST_BUFFER) return -1;

	// don't attempt to read more than what is available
	// in the current buffer.
	int read = Math.min(buffer.remaining(), len);
	assert read > 0 && read <= buffer.remaining();

	// buffer.get() will do the boundary check for us.
	buffer.get(bytes, off, read);
	return read;
	}

	@Override
	public int read() throws IOException {
	ByteBuffer buffer;
	if ((buffer = current()) == LAST_BUFFER) return -1;
	return buffer.get() & 0xFF;
	}

	@Override
	public void onSubscribe(Flow.Subscription s) {
	if (this.subscription != null) {
	s.cancel();
	return;
	}
	this.subscription = s;
	assert buffers.remainingCapacity() > 1; // should at least be 2
	if (DEBUG) err.println("onSubscribe: requesting "
	+ Math.max(1, buffers.remainingCapacity() - 1));
	s.request(Math.max(1, buffers.remainingCapacity() - 1));
	}

	@Override
	public void onNext(List<ByteBuffer> t) {
	try {
	if (DEBUG) err.println("next item received");
	if (!buffers.offer(t)) {
	throw new IllegalStateException("queue is full");
	}
	if (DEBUG) err.println("item offered");
	} catch (Exception ex) {
	failed = ex;
	try {
	close();
	} catch (IOException ex1) {
	// OK
	}
	}
	}

	@Override
	public void onError(Throwable thrwbl) {
	subscription = null;
	failed = thrwbl;
	}

	@Override
	public void onComplete() {
	subscription = null;
	onNext(LAST_LIST);
	}

	@Override
	public void close() throws IOException {
	synchronized (this) {
	if (closed) return;
	closed = true;
	}
	Flow.Subscription s = subscription;
	subscription = null;
	if (s != null) {
	s.cancel();
	}
	super.close();
	}

	}
	}

	/**
	* Examine the response headers to figure out the charset used to
	* encode the body content.
	* If the content type is not textual, returns an empty Optional.
	* Otherwise, returns the body content's charset, defaulting to
	* ISO-8859-1 if none is explicitly specified.
	* @param headers The response headers.
	* @return The charset to use for decoding the response body, if
	* the response body content is text/...
	*/
	public static Optional<Charset> getCharset(HttpHeaders headers) {
	Optional<String> contentType = headers.firstValue("Content-Type");
	Optional<Charset> charset = Optional.empty();
	if (contentType.isPresent()) {
	final String[] values = contentType.get().split(";");
	if (values[0].startsWith("text/")) {
	charset = Optional.of(Stream.of(values)
	.map(x -> x.toLowerCase(Locale.ROOT))
	.map(String::trim)
	.filter(x -> x.startsWith("charset="))
	.map(x -> x.substring("charset=".length()))
	.findFirst()
	.orElse("ISO-8859-1"))
	.map(Charset::forName);
	}
	}
	return charset;
	}

	public static void main(String[] args) throws Exception {
	HttpClient client = HttpClient.newHttpClient();
	HttpRequest request = HttpRequest
	.newBuilder(new URI("http://hg.openjdk.java.net/jdk9/sandbox/jdk/shortlog/http-client-branch/"))
	.GET()
	.build();

	// This example shows how to return an InputStream that can be used to
	// start reading the response body before the response is fully received.
	// In comparison, the snipet below (which uses
	// HttpResponse.BodyHandlers.ofString()) obviously will not return before the
	// response body is fully read:
	//
	// System.out.println(
	// client.sendAsync(request, HttpResponse.BodyHandlers.ofString()).get().body());

	CompletableFuture<HttpResponse<InputStream>> handle =
	client.sendAsync(request, new HttpInputStreamHandler(3));
	if (DEBUG) err.println("Request sent");

	HttpResponse<InputStream> pending = handle.get();

	// At this point, the response headers have been received, but the
	// response body may not have arrived yet. This comes from
	// the implementation of HttpResponseInputStream::getBody above,
	// which returns an already completed completion stage, without
	// waiting for any data.
	// We can therefore access the headers - and the body, which
	// is our live InputStream, without waiting...
	HttpHeaders responseHeaders = pending.headers();

	// Get the charset declared in the response headers.
	// The optional will be empty if the content type is not
	// of type text/...
	Optional<Charset> charset = getCharset(responseHeaders);

	try (InputStream is = pending.body();
	// We assume a textual content type. Construct an InputStream
	// Reader with the appropriate Charset.
	// charset.get() will throw NPE if the content is not textual.
	Reader r = new InputStreamReader(is, charset.get())) {

	char[] buff = new char[32];
	int off=0, n=0;
	if (DEBUG) err.println("Start receiving response body");
	if (DEBUG) err.println("Charset: " + charset.get());

	// Start consuming the InputStream as the data arrives.
	// Will block until there is something to read...
	while ((n = r.read(buff, off, buff.length - off)) > 0) {
	assert (buff.length - off) > 0;
	assert n <= (buff.length - off);
	if (n == (buff.length - off)) {
	System.out.print(buff);
	off = 0;
	} else {
	off += n;
	}
	assert off < buff.length;
	}

	// last call to read may not have filled 'buff' completely.
	// flush out the remaining characters.
	assert off >= 0 && off < buff.length;
	for (int i=0; i < off; i++) {
	System.out.print(buff[i]);
	}

	// We're done!
	System.out.println("Done!");
	}
	}

	}