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 org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.StatusLine; import org.apache.http.annotation.Immutable; import org.apache.http.client.HttpResponseException; import org.apache.http.client.ResponseHandler; import org.apache.http.util.EntityUtils; /** * A generic {@link ResponseHandler} that works with the response entity * for successful (2xx) responses. If the response code was >= 300, the response * body is consumed and an {@link HttpResponseException} is thrown. * <p> * If this is used with * {@link org.apache.http.client.HttpClient#execute( * org.apache.http.client.methods.HttpUriRequest, ResponseHandler)}, * HttpClient may handle redirects (3xx responses) internally. * </p> * * @since 4.4 */ @Immutable public abstract class AbstractResponseHandler<T> implements ResponseHandler<T> { /** * Read the entity from the response body and pass it to the entity handler * method if the response was successful (a 2xx status code). If no response * body exists, this returns null. If the response was unsuccessful (>= 300 * status code), throws an {@link HttpResponseException}. */ @Override public T handleResponse(final HttpResponse response) throws HttpResponseException, IOException { final StatusLine statusLine = response.getStatusLine(); final HttpEntity entity = response.getEntity(); if (statusLine.getStatusCode() >= 300) { EntityUtils.consume(entity); throw new HttpResponseException(statusLine.getStatusCode(), statusLine.getReasonPhrase()); } return entity == null ? null : handleEntity(entity); } /** * Handle the response entity and transform it into the actual response * object. */ public abstract T handleEntity(HttpEntity entity) throws IOException; }