io.grpc.Channel Maven / Gradle / Ivy
/*
* Copyright 2014 The gRPC Authors
*
* 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 io.grpc;
import javax.annotation.concurrent.ThreadSafe;
/**
* A virtual connection to a conceptual endpoint, to perform RPCs. A channel is free to have zero or
* many actual connections to the endpoint based on configuration, load, etc. A channel is also free
* to determine which actual endpoints to use and may change it every RPC, permitting client-side
* load balancing. Applications are generally expected to use stubs instead of calling this class
* directly.
*
* Applications can add common cross-cutting behaviors to stubs by decorating Channel
* implementations using {@link ClientInterceptor}. It is expected that most application
* code will not use this class directly but rather work with stubs that have been bound to a
* Channel that was decorated during application initialization.
*/
@ThreadSafe
public abstract class Channel {
/**
* Create a {@link ClientCall} to the remote operation specified by the given
* {@link MethodDescriptor}. The returned {@link ClientCall} does not trigger any remote
* behavior until {@link ClientCall#start(ClientCall.Listener, Metadata)} is
* invoked.
*
* @param methodDescriptor describes the name and parameter types of the operation to call.
* @param callOptions runtime options to be applied to this call.
* @return a {@link ClientCall} bound to the specified method.
* @since 1.0.0
*/
public abstract ClientCall newCall(
MethodDescriptor methodDescriptor, CallOptions callOptions);
/**
* The authority of the destination this channel connects to. Typically this is in the format
* {@code host:port}.
*
* @since 1.0.0
*/
public abstract String authority();
}