1 /* 2 * Copyright 2017 The gRPC Authors 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package io.grpc.internal; 18 19 import java.io.IOException; 20 import java.net.SocketAddress; 21 import javax.annotation.Nullable; 22 23 /** 24 * A utility class to detect which proxy, if any, should be used for a given 25 * {@link java.net.SocketAddress}. This class performs network requests to resolve address names, 26 * and should only be used in places that are expected to do IO such as the 27 * {@link io.grpc.NameResolver}. 28 */ 29 public interface ProxyDetector { 30 /** 31 * Given a target address, returns which proxy address should be used. If no proxy should be 32 * used, then return value will be null. The address of the {@link ProxyParameters} is always 33 * resolved. This throws if the proxy address cannot be resolved. 34 */ 35 @Nullable proxyFor(SocketAddress targetServerAddress)36 ProxyParameters proxyFor(SocketAddress targetServerAddress) throws IOException; 37 } 38