michael@0: /*
michael@0:  * ====================================================================
michael@0:  * Licensed to the Apache Software Foundation (ASF) under one
michael@0:  * or more contributor license agreements.  See the NOTICE file
michael@0:  * distributed with this work for additional information
michael@0:  * regarding copyright ownership.  The ASF licenses this file
michael@0:  * to you under the Apache License, Version 2.0 (the
michael@0:  * "License"); you may not use this file except in compliance
michael@0:  * with the License.  You may obtain a copy of the License at
michael@0:  *
michael@0:  *   http://www.apache.org/licenses/LICENSE-2.0
michael@0:  *
michael@0:  * Unless required by applicable law or agreed to in writing,
michael@0:  * software distributed under the License is distributed on an
michael@0:  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
michael@0:  * KIND, either express or implied.  See the License for the
michael@0:  * specific language governing permissions and limitations
michael@0:  * under the License.
michael@0:  * ====================================================================
michael@0:  *
michael@0:  * This software consists of voluntary contributions made by many
michael@0:  * individuals on behalf of the Apache Software Foundation.  For more
michael@0:  * information on the Apache Software Foundation, please see
michael@0:  * <http://www.apache.org/>.
michael@0:  *
michael@0:  */
michael@0: 
michael@0: package ch.boye.httpclientandroidlib.impl.client;
michael@0: 
michael@0: import java.io.IOException;
michael@0: import java.io.InterruptedIOException;
michael@0: import java.net.ConnectException;
michael@0: import java.net.UnknownHostException;
michael@0: 
michael@0: import javax.net.ssl.SSLException;
michael@0: 
michael@0: import ch.boye.httpclientandroidlib.annotation.Immutable;
michael@0: 
michael@0: import ch.boye.httpclientandroidlib.HttpEntityEnclosingRequest;
michael@0: import ch.boye.httpclientandroidlib.HttpRequest;
michael@0: import ch.boye.httpclientandroidlib.client.HttpRequestRetryHandler;
michael@0: import ch.boye.httpclientandroidlib.protocol.HttpContext;
michael@0: import ch.boye.httpclientandroidlib.protocol.ExecutionContext;
michael@0: 
michael@0: /**
michael@0:  * The default {@link HttpRequestRetryHandler} used by request executors.
michael@0:  *
michael@0:  *
michael@0:  * @since 4.0
michael@0:  */
michael@0: @Immutable
michael@0: public class DefaultHttpRequestRetryHandler implements HttpRequestRetryHandler {
michael@0: 
michael@0:     /** the number of times a method will be retried */
michael@0:     private final int retryCount;
michael@0: 
michael@0:     /** Whether or not methods that have successfully sent their request will be retried */
michael@0:     private final boolean requestSentRetryEnabled;
michael@0: 
michael@0:     /**
michael@0:      * Default constructor
michael@0:      */
michael@0:     public DefaultHttpRequestRetryHandler(int retryCount, boolean requestSentRetryEnabled) {
michael@0:         super();
michael@0:         this.retryCount = retryCount;
michael@0:         this.requestSentRetryEnabled = requestSentRetryEnabled;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Default constructor
michael@0:      */
michael@0:     public DefaultHttpRequestRetryHandler() {
michael@0:         this(3, false);
michael@0:     }
michael@0:     /**
michael@0:      * Used <code>retryCount</code> and <code>requestSentRetryEnabled</code> to determine
michael@0:      * if the given method should be retried.
michael@0:      */
michael@0:     public boolean retryRequest(
michael@0:             final IOException exception,
michael@0:             int executionCount,
michael@0:             final HttpContext context) {
michael@0:         if (exception == null) {
michael@0:             throw new IllegalArgumentException("Exception parameter may not be null");
michael@0:         }
michael@0:         if (context == null) {
michael@0:             throw new IllegalArgumentException("HTTP context may not be null");
michael@0:         }
michael@0:         if (executionCount > this.retryCount) {
michael@0:             // Do not retry if over max retry count
michael@0:             return false;
michael@0:         }
michael@0:         if (exception instanceof InterruptedIOException) {
michael@0:             // Timeout
michael@0:             return false;
michael@0:         }
michael@0:         if (exception instanceof UnknownHostException) {
michael@0:             // Unknown host
michael@0:             return false;
michael@0:         }
michael@0:         if (exception instanceof ConnectException) {
michael@0:             // Connection refused
michael@0:             return false;
michael@0:         }
michael@0:         if (exception instanceof SSLException) {
michael@0:             // SSL handshake exception
michael@0:             return false;
michael@0:         }
michael@0: 
michael@0:         HttpRequest request = (HttpRequest)
michael@0:             context.getAttribute(ExecutionContext.HTTP_REQUEST);
michael@0:         if (handleAsIdempotent(request)) {
michael@0:             // Retry if the request is considered idempotent
michael@0:             return true;
michael@0:         }
michael@0: 
michael@0:         Boolean b = (Boolean)
michael@0:             context.getAttribute(ExecutionContext.HTTP_REQ_SENT);
michael@0:         boolean sent = (b != null && b.booleanValue());
michael@0: 
michael@0:         if (!sent || this.requestSentRetryEnabled) {
michael@0:             // Retry if the request has not been sent fully or
michael@0:             // if it's OK to retry methods that have been sent
michael@0:             return true;
michael@0:         }
michael@0:         // otherwise do not retry
michael@0:         return false;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * @return <code>true</code> if this handler will retry methods that have
michael@0:      * successfully sent their request, <code>false</code> otherwise
michael@0:      */
michael@0:     public boolean isRequestSentRetryEnabled() {
michael@0:         return requestSentRetryEnabled;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * @return the maximum number of times a method will be retried
michael@0:      */
michael@0:     public int getRetryCount() {
michael@0:         return retryCount;
michael@0:     }
michael@0: 
michael@0:     private boolean handleAsIdempotent(final HttpRequest request) {
michael@0:         return !(request instanceof HttpEntityEnclosingRequest);
michael@0:     }
michael@0: 
michael@0: }