Merge pull request ReactiveX#397 from benjchristensen/apache-async-http

Observable API for Apache HttpAsyncClient 4.0

Author: benjchristensen

rxjava-contrib/rxjava-apache-http/build.gradle

@@ -0,0 +1,20 @@
+apply plugin: 'osgi'
+
+sourceCompatibility = JavaVersion.VERSION_1_6
+targetCompatibility = JavaVersion.VERSION_1_6
+
+dependencies {
+    compile project(':rxjava-core')
+    compile 'org.apache.httpcomponents:httpclient:4.3'
+    compile 'org.apache.httpcomponents:httpcore-nio:4.3'
+    compile 'org.apache.httpcomponents:httpasyncclient:4.0-beta4'
+}
+
+jar {
+    manifest {
+        name = 'rxjava-apache-http'
+        instruction 'Bundle-Vendor', 'Netflix'
+        instruction 'Bundle-DocURL', 'https://github.com/Netflix/RxJava'
+        instruction 'Import-Package', '!org.junit,!junit.framework,!org.mockito.*,*'
+    }
+}

rxjava-contrib/rxjava-apache-http/src/main/java/rx/apache/http/ObservableHttp.java

@@ -0,0 +1,171 @@
+/**
+ * Copyright 2013 Netflix, Inc.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package rx.apache.http;
+
+import org.apache.http.HttpResponse;
+import org.apache.http.client.HttpClient;
+import org.apache.http.concurrent.FutureCallback;
+import org.apache.http.nio.client.HttpAsyncClient;
+import org.apache.http.nio.client.methods.HttpAsyncMethods;
+import org.apache.http.nio.protocol.HttpAsyncRequestProducer;
+
+import rx.Observable;
+import rx.Observable.OnSubscribeFunc;
+import rx.Observer;
+import rx.Subscription;
+import rx.apache.http.consumers.ResponseConsumerDelegate;
+import rx.subscriptions.CompositeSubscription;
+import rx.subscriptions.Subscriptions;
+
+/**
+ * An {@link Observable} interface to Apache {@link HttpAsyncClient}.
+ * <p>
+ * The initial {@link HttpResponse} is returned via {@link Observer#onNext} wrapped in a {@link ObservableHttpResponse}.
+ * <p>
+ * The content stream is retrieved from {@link ObservableHttpResponse#getContent()}.
+ * <p>
+ * It is aware of Content-Type <i>text/event-stream</i> and will stream each event via {@link Observer#onNext}.
+ * <p>
+ * Other Content-Types will be returned as a single call to {@link Observer#onNext}.
+ * <p>
+ * Examples:
+ * <p>
+ * <pre> {@code
+ * ObservableHttp.createGet("http://www.wikipedia.com", httpClient).toObservable();
+ * } </pre>
+ * <p>
+ * <pre> {@code
+ * ObservableHttp.createRequest(HttpAsyncMethods.createGet("http://www.wikipedia.com"), httpClient).toObservable();
+ * } </pre>
+ * 
+ * An {@link HttpClient} can be created like this:
+ * 
+ * <pre> {@code
+ * CloseableHttpAsyncClient httpClient = HttpAsyncClients.createDefault();
+ * httpClient.start(); // start it
+ * httpClient.stop(); // stop it
+ * } </pre>
+ * <p>
+ * A client with custom configurations can be created like this:
+ * </p>
+ * <pre> {@code
+ * final RequestConfig requestConfig = RequestConfig.custom()
+ *     .setSocketTimeout(1000)
+ *     .setConnectTimeout(200).build();
+ * final CloseableHttpAsyncClient httpClient = HttpAsyncClients.custom()
+ *     .setDefaultRequestConfig(requestConfig)
+ *     .setMaxConnPerRoute(20)
+ *     .setMaxConnTotal(50)
+ *     .build();
+ * httpClient.start();
+ * }</pre>
+ * <p>
+ * 
+ * @param <T>
+ */
+public class ObservableHttp<T> {
+
+    private final OnSubscribeFunc<T> onSubscribe;
+
+    private ObservableHttp(OnSubscribeFunc<T> onSubscribe) {
+        this.onSubscribe = onSubscribe;
+    }
+
+    private static <T> ObservableHttp<T> create(OnSubscribeFunc<T> onSubscribe) {
+        return new ObservableHttp<T>(onSubscribe);
+    }
+
+    public Observable<T> toObservable() {
+        return Observable.create(new OnSubscribeFunc<T>() {
+
+            @Override
+            public Subscription onSubscribe(Observer<? super T> observer) {
+                return onSubscribe.onSubscribe(observer);
+            }
+        });
+    }
+
+    public static ObservableHttp<ObservableHttpResponse> createGet(String uri, final HttpAsyncClient client) {
+        return createRequest(HttpAsyncMethods.createGet(uri), client);
+    }
+
+    /**
+     * Execute request using {@link HttpAsyncRequestProducer} to define HTTP Method, URI and payload (if applicable).
+     * <p>
+     * If the response is chunked (or flushed progressively such as with <i>text/event-stream</i> <a href="http://www.w3.org/TR/2009/WD-eventsource-20091029/">Server-Sent Events</a>) this will call
+     * {@link Observer#onNext} multiple times.
+     * <p>
+     * Use {@code HttpAsyncMethods.create* } factory methods to create {@link HttpAsyncRequestProducer} instances.
+     * <p>
+     * A client can be retrieved like this:
+     * <p>
+     * <pre> {@code      CloseableHttpAsyncClient httpclient = HttpAsyncClients.createDefault(); } </pre> </p>
+     * <p>
+     * A client with custom configurations can be created like this:
+     * </p>
+     * <pre> {@code
+     * final RequestConfig requestConfig = RequestConfig.custom()
+     *     .setSocketTimeout(3000)
+     *     .setConnectTimeout(3000).build();
+     * final CloseableHttpAsyncClient httpclient = HttpAsyncClients.custom()
+     *     .setDefaultRequestConfig(requestConfig)
+     *     .setMaxConnPerRoute(20)
+     *     .setMaxConnTotal(50)
+     *     .build();
+     * httpclient.start();
+     * }</pre>
+     * 
+     * 
+     * @param requestProducer
+     * @param client
+     * @return
+     */
+    public static ObservableHttp<ObservableHttpResponse> createRequest(final HttpAsyncRequestProducer requestProducer, final HttpAsyncClient client) {
+
+        return ObservableHttp.create(new OnSubscribeFunc<ObservableHttpResponse>() {
+
+            @Override
+            public Subscription onSubscribe(final Observer<? super ObservableHttpResponse> observer) {
+
+                final CompositeSubscription parentSubscription = new CompositeSubscription();
+
+                // return a Subscription that wraps the Future so it can be cancelled
+                parentSubscription.add(Subscriptions.create(client.execute(requestProducer, new ResponseConsumerDelegate(observer, parentSubscription),
+                        new FutureCallback<HttpResponse>() {
+
+                            @Override
+                            public void completed(HttpResponse result) {
+                                observer.onCompleted();
+                            }
+
+                            @Override
+                            public void failed(Exception ex) {
+                                observer.onError(ex);
+                            }
+
+                            @Override
+                            public void cancelled() {
+                                observer.onCompleted();
+                            }
+
+                        })));
+
+                return parentSubscription;
+            }
+        });
+    }
+
+}

rxjava-contrib/rxjava-apache-http/src/main/java/rx/apache/http/ObservableHttpResponse.java

@@ -0,0 +1,51 @@
+/**
+ * Copyright 2013 Netflix, Inc.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package rx.apache.http;
+
+import org.apache.http.HttpResponse;
+
+import rx.Observable;
+
+/**
+ * The {@link HttpResponse} for the entire request and accessor to {@link Observable} of the content stream.
+ */
+public class ObservableHttpResponse {
+
+    private final HttpResponse response;
+    private final Observable<byte[]> contentSubscription;
+
+    public ObservableHttpResponse(HttpResponse response, Observable<byte[]> contentSubscription) {
+        this.response = response;
+        this.contentSubscription = contentSubscription;
+    }
+
+    /**
+     * The {@link HttpResponse} returned by the Apache client at the beginning of the response.
+     * 
+     * @return {@link HttpResponse} with HTTP status codes, headers, etc
+     */
+    public HttpResponse getResponse() {
+        return response;
+    }
+
+    /**
+     * If the response is not chunked then only a single array will be returned. If chunked then multiple arrays.
+     */
+    public Observable<byte[]> getContent() {
+        return contentSubscription;
+    }
+
+}

rxjava-contrib/rxjava-apache-http/src/main/java/rx/apache/http/consumers/ExpandableByteBuffer.java

@@ -0,0 +1,65 @@
+/**
+ * Copyright 2013 Netflix, Inc.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package rx.apache.http.consumers;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import org.apache.http.nio.util.ExpandableBuffer;
+import org.apache.http.nio.util.HeapByteBufferAllocator;
+
+class ExpandableByteBuffer extends ExpandableBuffer {
+    public ExpandableByteBuffer(int size) {
+        super(size, HeapByteBufferAllocator.INSTANCE);
+    }
+
+    public ExpandableByteBuffer() {
+        super(4 * 1024, HeapByteBufferAllocator.INSTANCE);
+    }
+
+    public void addByte(byte b) {
+        if (this.buffer.remaining() == 0) {
+            expand();
+        }
+        this.buffer.put(b);
+    }
+
+    public boolean hasContent() {
+        return this.buffer.position() > 0;
+    }
+
+    public byte[] getBytes() {
+        byte[] data = new byte[this.buffer.position()];
+        this.buffer.position(0);
+        this.buffer.get(data);
+        return data;
+    }
+
+    public void reset() {
+        clear();
+    }
+
+    public void consumeInputStream(InputStream content) throws IOException {
+        try {
+            int b = -1;
+            while ((b = content.read()) != -1) {
+                addByte((byte) b);
+            }
+        } finally {
+            content.close();
+        }
+    }
+}