Java tutorial
/* * ==================================================================== * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the Apache Software Foundation. For more * information on the Apache Software Foundation, please see * <http://www.apache.org/>. * */ package org.apache.http.conn.routing; /** * Provides directions on establishing a route. * Implementations of this interface compare a planned route with * a tracked route and indicate the next step required. * * @since 4.0 */ public interface HttpRouteDirector { /** Indicates that the route can not be established at all. */ public final static int UNREACHABLE = -1; /** Indicates that the route is complete. */ public final static int COMPLETE = 0; /** Step: open connection to target. */ public final static int CONNECT_TARGET = 1; /** Step: open connection to proxy. */ public final static int CONNECT_PROXY = 2; /** Step: tunnel through proxy to target. */ public final static int TUNNEL_TARGET = 3; /** Step: tunnel through proxy to other proxy. */ public final static int TUNNEL_PROXY = 4; /** Step: layer protocol (over tunnel). */ public final static int LAYER_PROTOCOL = 5; /** * Provides the next step. * * @param plan the planned route * @param fact the currently established route, or * <code>null</code> if nothing is established * * @return one of the constants defined in this interface, indicating * either the next step to perform, or success, or failure. * 0 is for success, a negative value for failure. */ public int nextStep(RouteInfo plan, RouteInfo fact); }