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 package org.apache.hc.client5.http; 28 29 import org.apache.hc.core5.annotation.Contract; 30 import org.apache.hc.core5.annotation.ThreadingBehavior; 31 import org.apache.hc.core5.http.HttpResponse; 32 import org.apache.hc.core5.http.protocol.HttpContext; 33 import org.apache.hc.core5.util.TimeValue; 34 35 /** 36 * Interface for deciding how long a connection can remain 37 * idle before being reused. 38 * <p> 39 * Implementations of this interface must be thread-safe. Access to shared 40 * data must be synchronized as methods of this interface may be executed 41 * from multiple threads. 42 * 43 * @since 4.0 44 */ 45 @Contract(threading = ThreadingBehavior.STATELESS) 46 public interface ConnectionKeepAliveStrategy { 47 48 /** 49 * Returns the duration of time which this connection can be safely kept 50 * idle. If the connection is left idle for longer than this period of time, 51 * it MUST not reused. A value of 0 or less may be returned to indicate that 52 * there is no suitable suggestion. 53 * 54 * When coupled with a {@link org.apache.hc.core5.http.ConnectionReuseStrategy}, if 55 * {@link org.apache.hc.core5.http.ConnectionReuseStrategy#keepAlive( 56 * org.apache.hc.core5.http.HttpRequest, HttpResponse, HttpContext)} returns true, 57 * this allows you to control how long the reuse will last. If keepAlive returns 58 * false, this should have no meaningful impact 59 * 60 * @param response 61 * The last response received over the connection. 62 * @param context 63 * the context in which the connection is being used. 64 * 65 * @return the duration in ms for which it is safe to keep the connection 66 * idle, or <=0 if no suggested duration. 67 */ 68 TimeValue getKeepAliveDuration(HttpResponse response, HttpContext context); 69 70 }