1 /* 2 * ==================================================================== 3 * Licensed to the Apache Software Foundation (ASF) under one 4 * or more contributor license agreements. See the NOTICE file 5 * distributed with this work for additional information 6 * regarding copyright ownership. The ASF licenses this file 7 * to you under the Apache License, Version 2.0 (the 8 * "License"); you may not use this file except in compliance 9 * with the License. You may obtain a copy of the License at 10 * 11 * http://www.apache.org/licenses/LICENSE-2.0 12 * 13 * Unless required by applicable law or agreed to in writing, 14 * software distributed under the License is distributed on an 15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 16 * KIND, either express or implied. See the License for the 17 * specific language governing permissions and limitations 18 * under the License. 19 * ==================================================================== 20 * 21 * This software consists of voluntary contributions made by many 22 * individuals on behalf of the Apache Software Foundation. For more 23 * information on the Apache Software Foundation, please see 24 * <http://www.apache.org/>. 25 * 26 */ 27 28 package org.apache.hc.client5.http.routing; 29 30 import org.apache.hc.client5.http.HttpRoute; 31 import org.apache.hc.core5.annotation.Contract; 32 import org.apache.hc.core5.annotation.ThreadingBehavior; 33 import org.apache.hc.core5.http.HttpException; 34 import org.apache.hc.core5.http.HttpHost; 35 import org.apache.hc.core5.http.HttpRequest; 36 import org.apache.hc.core5.http.protocol.HttpContext; 37 38 /** 39 * Encapsulates logic to compute a {@link HttpRoute} to a target host. 40 * Implementations may for example be based on parameters, or on the 41 * standard Java system properties. 42 * <p> 43 * Implementations of this interface must be thread-safe. Access to shared 44 * data must be synchronized as methods of this interface may be executed 45 * from multiple threads. 46 * </p> 47 * 48 * @since 4.0 49 */ 50 @Contract(threading = ThreadingBehavior.STATELESS) 51 public interface HttpRoutePlanner { 52 53 /** 54 * Determines the route for the given host. 55 * 56 * @param target the target host for the request. 57 * @param context the context to use for the subsequent execution. 58 * Implementations may accept {@code null}. 59 * 60 * @return the route that the request should take 61 * 62 * @throws HttpException in case of a problem 63 */ 64 HttpRoute determineRoute(HttpHost target, HttpContext context) throws HttpException; 65 66 /** 67 * Determines the route for the given host. 68 * 69 * @param target the target host for the request. 70 * @param request the request message. Can be {@code null} if not given / known. 71 * @param context the context to use for the subsequent execution. 72 * Implementations may accept {@code null}. 73 * 74 * @return the route that the request should take 75 * @throws HttpException in case of a problem. 76 * 77 * @since 5.4 78 */ 79 default HttpRoute determineRoute(HttpHost target, HttpRequest request, HttpContext context) throws HttpException { 80 return determineRoute(target, context); 81 } 82 83 }