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.impl.client; import java.io.IOException; import java.io.InterruptedIOException; import java.net.URI; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.http.HttpHost; import org.apache.http.HttpRequest; import org.apache.http.HttpResponse; import org.apache.http.annotation.ThreadSafe; import org.apache.http.client.HttpClient; import org.apache.http.client.ResponseHandler; import org.apache.http.client.ServiceUnavailableRetryStrategy; import org.apache.http.client.methods.HttpUriRequest; import org.apache.http.conn.ClientConnectionManager; import org.apache.http.params.HttpParams; import org.apache.http.protocol.HttpContext; import org.apache.http.util.Args; import org.apache.http.util.EntityUtils; /** * {@link HttpClient} implementation that can automatically retry the request in case of * a non-2xx response using the {@link ServiceUnavailableRetryStrategy} interface. * * @since 4.2 * * @deprecated (4.3) use {@link HttpClientBuilder}. */ @Deprecated @ThreadSafe public class AutoRetryHttpClient implements HttpClient { private final HttpClient backend; private final ServiceUnavailableRetryStrategy retryStrategy; private final Log log = LogFactory.getLog(getClass()); public AutoRetryHttpClient(final HttpClient client, final ServiceUnavailableRetryStrategy retryStrategy) { super(); Args.notNull(client, "HttpClient"); Args.notNull(retryStrategy, "ServiceUnavailableRetryStrategy"); this.backend = client; this.retryStrategy = retryStrategy; } /** * Constructs a {@code AutoRetryHttpClient} with default caching settings that * stores cache entries in memory and uses a vanilla * {@link DefaultHttpClient} for backend requests. */ public AutoRetryHttpClient() { this(new DefaultHttpClient(), new DefaultServiceUnavailableRetryStrategy()); } /** * Constructs a {@code AutoRetryHttpClient} with the given caching options that * stores cache entries in memory and uses a vanilla * {@link DefaultHttpClient} for backend requests. * * @param config * retry configuration module options */ public AutoRetryHttpClient(final ServiceUnavailableRetryStrategy config) { this(new DefaultHttpClient(), config); } /** * Constructs a {@code AutoRetryHttpClient} with default caching settings that * stores cache entries in memory and uses the given {@link HttpClient} for * backend requests. * * @param client * used to make origin requests */ public AutoRetryHttpClient(final HttpClient client) { this(client, new DefaultServiceUnavailableRetryStrategy()); } public HttpResponse execute(final HttpHost target, final HttpRequest request) throws IOException { final HttpContext defaultContext = null; return execute(target, request, defaultContext); } public <T> T execute(final HttpHost target, final HttpRequest request, final ResponseHandler<? extends T> responseHandler) throws IOException { return execute(target, request, responseHandler, null); } public <T> T execute(final HttpHost target, final HttpRequest request, final ResponseHandler<? extends T> responseHandler, final HttpContext context) throws IOException { final HttpResponse resp = execute(target, request, context); return responseHandler.handleResponse(resp); } public HttpResponse execute(final HttpUriRequest request) throws IOException { final HttpContext context = null; return execute(request, context); } public HttpResponse execute(final HttpUriRequest request, final HttpContext context) throws IOException { final URI uri = request.getURI(); final HttpHost httpHost = new HttpHost(uri.getHost(), uri.getPort(), uri.getScheme()); return execute(httpHost, request, context); } public <T> T execute(final HttpUriRequest request, final ResponseHandler<? extends T> responseHandler) throws IOException { return execute(request, responseHandler, null); } public <T> T execute(final HttpUriRequest request, final ResponseHandler<? extends T> responseHandler, final HttpContext context) throws IOException { final HttpResponse resp = execute(request, context); return responseHandler.handleResponse(resp); } public HttpResponse execute(final HttpHost target, final HttpRequest request, final HttpContext context) throws IOException { for (int c = 1;; c++) { final HttpResponse response = backend.execute(target, request, context); try { if (retryStrategy.retryRequest(response, c, context)) { EntityUtils.consume(response.getEntity()); final long nextInterval = retryStrategy.getRetryInterval(); try { log.trace("Wait for " + nextInterval); Thread.sleep(nextInterval); } catch (final InterruptedException e) { Thread.currentThread().interrupt(); throw new InterruptedIOException(); } } else { return response; } } catch (final RuntimeException ex) { try { EntityUtils.consume(response.getEntity()); } catch (final IOException ioex) { log.warn("I/O error consuming response content", ioex); } throw ex; } } } public ClientConnectionManager getConnectionManager() { return backend.getConnectionManager(); } public HttpParams getParams() { return backend.getParams(); } }