Initial implementation of CronetBidirectionalStream.

components/cronet/android/api/src/org/chromium/net/BidirectionalStream.java

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.net;
 
 import android.support.annotation.IntDef;
 
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ skipping 70 matching lines @@
         }
 
         /**
          * Sets the HTTP method for the request. Returns builder to facilitate chaining.
          *
          * @param method the method to use for request. Default is 'POST'
          * @return the builder to facilitate chaining
          */
         public Builder setHttpMethod(String method) {
             if (method == null) {
-                throw new NullPointerException("Invalid method name.");
+                throw new NullPointerException("Method is required.");
             }
             mHttpMethod = method;
             return this;
         }
 
         /**
          * Adds a request header. Returns builder to facilitate chaining.
          *
          * @param header the header name
          * @param value the header value
@@ skipping 45 matching lines @@
         /**
          * Sets priority of the stream which should be one of the
          * {@link #STREAM_PRIORITY_IDLE STREAM_PRIORITY_*} values.
          * The stream is given {@link #STREAM_PRIORITY_MEDIUM} priority if {@link
          * #setPriority} is not called.
          *
          * @param priority priority of the stream which should be one of the
          *         {@link #STREAM_PRIORITY_IDLE STREAM_PRIORITY_*} values.
          * @return the builder to facilitate chaining.
          */
         public Builder setPriority(@StreamPriority int priority) {

[kapishnikov, 2016/01/22 16:58:14]

Not related to this CL but I noticed that @StreamPriority annotation is
deprecated/hidden. Since this is the public API we should find a better
alternative.

[mef, 2016/01/22 17:36:06]

Yeah, we need to re-work the whole priority API, so we didn't want to publicly
expose this yet.

             mPriority = priority;
             return this;
         }
 
         /**
          * Creates a {@link BidirectionalStream} using configuration from this
          * {@link Builder}. The returned {@code BidirectionalStream} can then be started
          * by calling {@link BidirectionalStream#start}.
          *
          * @return constructed {@link BidirectionalStream} using configuration from
          *         this {@link Builder}
          */
         public BidirectionalStream build() {
             return mCronetEngine.createBidirectionalStream(
                     mUrl, mCallback, mExecutor, mHttpMethod, mRequestHeaders, mPriority);
         }
     }
 
     /**
      * Callback class used to receive callbacks from a {@link BidirectionalStream}.
      */
     public abstract static class Callback {

[kapishnikov, 2016/01/22 16:58:14]

I wonder why the Callback class is a class and not an interface. Most of its
methods are abstract. The ones that are not abstract are empty. Since Java does
not support multiple inheritance, this may force the implementers to create an
inner class which is not always desirable. If needed, we can have a
DefaultCallback class that implements Callback to provide default implementation
with no-op methods.

[mef, 2016/01/22 17:36:06]

Per Android API guidelines.

         /**
          * Invoked when request headers are sent. Indicates that stream has initiated the request.
          * Consumer may call {@link BidirectionalStream#write write()} to start writing data.
          *
          * @param stream the stream on which request headers were sent
          */
         public abstract void onRequestHeadersSent(BidirectionalStream stream);
 
         /**
          * Invoked when initial response headers are received. Headers are available from
@@ skipping 209 matching lines @@
     /**
      * Returns {@code true} if the stream was successfully started and is now
      * done (succeeded, canceled, or failed).
      *
      * @return {@code true} if the stream was successfully started and is now
      *         done (completed, canceled, or failed), otherwise returns {@code false}
      *         to indicate stream is not yet started or is in progress.
      */
     public abstract boolean isDone();
 }