001// ***************************************************************************************************************************
002// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements.  See the NOTICE file *
003// * distributed with this work for additional information regarding copyright ownership.  The ASF licenses this file        *
004// * to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance            *
005// * with the License.  You may obtain a copy of the License at                                                              *
006// *                                                                                                                         *
007// *  http://www.apache.org/licenses/LICENSE-2.0                                                                             *
008// *                                                                                                                         *
009// * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an  *
010// * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the License for the        *
011// * specific language governing permissions and limitations under the License.                                              *
012// ***************************************************************************************************************************
013package org.apache.juneau.rest.client;
014
015import org.apache.http.*;
016
017/**
018 * Used to determine whether a request should be retried based on the HTTP response code.
019 *
020 * <p>
021 * Subclasses should override either the {@link #onCode(int)} method (if you only care about the HTTP status code)
022 * or {@link #onResponse(HttpResponse)} (if you want full access to the HTTP response object.
023 */
024public abstract class RetryOn {
025
026   /**
027    * Default RetryOn that returns <jk>true</jk> of any HTTP response &gt;= 400 is received.
028    */
029   public static final RetryOn DEFAULT = new RetryOn() {
030      @Override /* RetryOn */
031      public boolean onCode(int httpResponseCode) {
032         return httpResponseCode <= 0 || httpResponseCode >= 400;
033      }
034   };
035
036   /**
037    * Default RetryOn that returns <jk>true</jk> if the HTTP connection could not be made.
038    */
039   public static final RetryOn CONNECTION_LOST = new RetryOn() {
040      @Override /* RetryOn */
041      public boolean onCode(int httpResponseCode) {
042         return httpResponseCode <= 0;
043      }
044   };
045
046   /**
047    * Subclasses should override this method to determine whether the HTTP response is retryable.
048    *
049    * @param response The HTTP response object.  May be <jk>null</jk> if a connection could not be made.
050    * @return <jk>true</jk> if the specified response code is retryable.
051    */
052   protected boolean onResponse(HttpResponse response) {
053      return onCode(response == null || response.getStatusLine() == null ? -1 : response.getStatusLine().getStatusCode());
054   }
055
056   /**
057    * Subclasses should override this method to determine whether the HTTP response is retryable.
058    *
059    * @param httpResponseCode The HTTP response code.  <code>-1</code> if a connection could not be made.
060    * @return <jk>true</jk> if the specified response code is retryable.
061    */
062   protected boolean onCode(int httpResponseCode) {
063      return false;
064   }
065}