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.client;
michael@0: 
michael@0: import java.io.IOException;
michael@0: 
michael@0: import ch.boye.httpclientandroidlib.HttpHost;
michael@0: import ch.boye.httpclientandroidlib.HttpRequest;
michael@0: import ch.boye.httpclientandroidlib.HttpResponse;
michael@0: import ch.boye.httpclientandroidlib.client.methods.HttpUriRequest;
michael@0: import ch.boye.httpclientandroidlib.conn.ClientConnectionManager;
michael@0: import ch.boye.httpclientandroidlib.params.HttpParams;
michael@0: import ch.boye.httpclientandroidlib.protocol.HttpContext;
michael@0: 
michael@0: /**
michael@0:  * This interface represents only the most basic contract for HTTP request
michael@0:  * execution. It imposes no restrictions or particular details on the request
michael@0:  * execution process and leaves the specifics of state management,
michael@0:  * authentication and redirect handling up to individual implementations.
michael@0:  * This should make it easier to decorate the interface with additional
michael@0:  * functionality such as response content caching.
michael@0:  * <p/>
michael@0:  * The usual execution flow can be demonstrated by the code snippet below:
michael@0:  * <PRE>
michael@0:  * HttpClient httpclient = new DefaultHttpClient();
michael@0:  *
michael@0:  * // Prepare a request object
michael@0:  * HttpGet httpget = new HttpGet("http://www.apache.org/");
michael@0:  *
michael@0:  * // Execute the request
michael@0:  * HttpResponse response = httpclient.execute(httpget);
michael@0:  *
michael@0:  * // Examine the response status
michael@0:  * System.out.println(response.getStatusLine());
michael@0:  *
michael@0:  * // Get hold of the response entity
michael@0:  * HttpEntity entity = response.getEntity();
michael@0:  *
michael@0:  * // If the response does not enclose an entity, there is no need
michael@0:  * // to worry about connection release
michael@0:  * if (entity != null) {
michael@0:  *     InputStream instream = entity.getContent();
michael@0:  *     try {
michael@0:  *
michael@0:  *         BufferedReader reader = new BufferedReader(
michael@0:  *                 new InputStreamReader(instream));
michael@0:  *         // do something useful with the response
michael@0:  *         System.out.println(reader.readLine());
michael@0:  *
michael@0:  *     } catch (IOException ex) {
michael@0:  *
michael@0:  *         // In case of an IOException the connection will be released
michael@0:  *         // back to the connection manager automatically
michael@0:  *         throw ex;
michael@0:  *
michael@0:  *     } catch (RuntimeException ex) {
michael@0:  *
michael@0:  *         // In case of an unexpected exception you may want to abort
michael@0:  *         // the HTTP request in order to shut down the underlying
michael@0:  *         // connection and release it back to the connection manager.
michael@0:  *         httpget.abort();
michael@0:  *         throw ex;
michael@0:  *
michael@0:  *     } finally {
michael@0:  *
michael@0:  *         // Closing the input stream will trigger connection release
michael@0:  *         instream.close();
michael@0:  *
michael@0:  *     }
michael@0:  *
michael@0:  *     // When HttpClient instance is no longer needed,
michael@0:  *     // shut down the connection manager to ensure
michael@0:  *     // immediate deallocation of all system resources
michael@0:  *     httpclient.getConnectionManager().shutdown();
michael@0:  * }
michael@0:  * </PRE>
michael@0:  *
michael@0:  * @since 4.0
michael@0:  */
michael@0: public interface HttpClient {
michael@0: 
michael@0: 
michael@0:     /**
michael@0:      * Obtains the parameters for this client.
michael@0:      * These parameters will become defaults for all requests being
michael@0:      * executed with this client, and for the parameters of
michael@0:      * dependent objects in this client.
michael@0:      *
michael@0:      * @return  the default parameters
michael@0:      */
michael@0:     HttpParams getParams();
michael@0: 
michael@0:     /**
michael@0:      * Obtains the connection manager used by this client.
michael@0:      *
michael@0:      * @return  the connection manager
michael@0:      */
michael@0:     ClientConnectionManager getConnectionManager();
michael@0: 
michael@0:     /**
michael@0:      * Executes a request using the default context.
michael@0:      *
michael@0:      * @param request   the request to execute
michael@0:      *
michael@0:      * @return  the response to the request. This is always a final response,
michael@0:      *          never an intermediate response with an 1xx status code.
michael@0:      *          Whether redirects or authentication challenges will be returned
michael@0:      *          or handled automatically depends on the implementation and
michael@0:      *          configuration of this client.
michael@0:      * @throws IOException in case of a problem or the connection was aborted
michael@0:      * @throws ClientProtocolException in case of an http protocol error
michael@0:      */
michael@0:     HttpResponse execute(HttpUriRequest request)
michael@0:         throws IOException, ClientProtocolException;
michael@0: 
michael@0:     /**
michael@0:      * Executes a request using the given context.
michael@0:      * The route to the target will be determined by the HTTP client.
michael@0:      *
michael@0:      * @param request   the request to execute
michael@0:      * @param context   the context to use for the execution, or
michael@0:      *                  <code>null</code> to use the default context
michael@0:      *
michael@0:      * @return  the response to the request. This is always a final response,
michael@0:      *          never an intermediate response with an 1xx status code.
michael@0:      *          Whether redirects or authentication challenges will be returned
michael@0:      *          or handled automatically depends on the implementation and
michael@0:      *          configuration of this client.
michael@0:      * @throws IOException in case of a problem or the connection was aborted
michael@0:      * @throws ClientProtocolException in case of an http protocol error
michael@0:      */
michael@0:     HttpResponse execute(HttpUriRequest request, HttpContext context)
michael@0:         throws IOException, ClientProtocolException;
michael@0: 
michael@0:     /**
michael@0:      * Executes a request to the target using the default context.
michael@0:      *
michael@0:      * @param target    the target host for the request.
michael@0:      *                  Implementations may accept <code>null</code>
michael@0:      *                  if they can still determine a route, for example
michael@0:      *                  to a default target or by inspecting the request.
michael@0:      * @param request   the request to execute
michael@0:      *
michael@0:      * @return  the response to the request. This is always a final response,
michael@0:      *          never an intermediate response with an 1xx status code.
michael@0:      *          Whether redirects or authentication challenges will be returned
michael@0:      *          or handled automatically depends on the implementation and
michael@0:      *          configuration of this client.
michael@0:      * @throws IOException in case of a problem or the connection was aborted
michael@0:      * @throws ClientProtocolException in case of an http protocol error
michael@0:      */
michael@0:     HttpResponse execute(HttpHost target, HttpRequest request)
michael@0:         throws IOException, ClientProtocolException;
michael@0: 
michael@0:     /**
michael@0:      * Executes a request to the target using the given context.
michael@0:      *
michael@0:      * @param target    the target host for the request.
michael@0:      *                  Implementations may accept <code>null</code>
michael@0:      *                  if they can still determine a route, for example
michael@0:      *                  to a default target or by inspecting the request.
michael@0:      * @param request   the request to execute
michael@0:      * @param context   the context to use for the execution, or
michael@0:      *                  <code>null</code> to use the default context
michael@0:      *
michael@0:      * @return  the response to the request. This is always a final response,
michael@0:      *          never an intermediate response with an 1xx status code.
michael@0:      *          Whether redirects or authentication challenges will be returned
michael@0:      *          or handled automatically depends on the implementation and
michael@0:      *          configuration of this client.
michael@0:      * @throws IOException in case of a problem or the connection was aborted
michael@0:      * @throws ClientProtocolException in case of an http protocol error
michael@0:      */
michael@0:     HttpResponse execute(HttpHost target, HttpRequest request,
michael@0:                          HttpContext context)
michael@0:         throws IOException, ClientProtocolException;
michael@0: 
michael@0:     /**
michael@0:      * Executes a request using the default context and processes the
michael@0:      * response using the given response handler.
michael@0:      *
michael@0:      * @param request   the request to execute
michael@0:      * @param responseHandler the response handler
michael@0:      *
michael@0:      * @return  the response object as generated by the response handler.
michael@0:      * @throws IOException in case of a problem or the connection was aborted
michael@0:      * @throws ClientProtocolException in case of an http protocol error
michael@0:      */
michael@0:     <T> T execute(
michael@0:             HttpUriRequest request,
michael@0:             ResponseHandler<? extends T> responseHandler)
michael@0:         throws IOException, ClientProtocolException;
michael@0: 
michael@0:     /**
michael@0:      * Executes a request using the given context and processes the
michael@0:      * response using the given response handler.
michael@0:      *
michael@0:      * @param request   the request to execute
michael@0:      * @param responseHandler the response handler
michael@0:      *
michael@0:      * @return  the response object as generated by the response handler.
michael@0:      * @throws IOException in case of a problem or the connection was aborted
michael@0:      * @throws ClientProtocolException in case of an http protocol error
michael@0:      */
michael@0:     <T> T execute(
michael@0:             HttpUriRequest request,
michael@0:             ResponseHandler<? extends T> responseHandler,
michael@0:             HttpContext context)
michael@0:         throws IOException, ClientProtocolException;
michael@0: 
michael@0:     /**
michael@0:      * Executes a request to the target using the default context and
michael@0:      * processes the response using the given response handler.
michael@0:      *
michael@0:      * @param target    the target host for the request.
michael@0:      *                  Implementations may accept <code>null</code>
michael@0:      *                  if they can still determine a route, for example
michael@0:      *                  to a default target or by inspecting the request.
michael@0:      * @param request   the request to execute
michael@0:      * @param responseHandler the response handler
michael@0:      *
michael@0:      * @return  the response object as generated by the response handler.
michael@0:      * @throws IOException in case of a problem or the connection was aborted
michael@0:      * @throws ClientProtocolException in case of an http protocol error
michael@0:      */
michael@0:     <T> T execute(
michael@0:             HttpHost target,
michael@0:             HttpRequest request,
michael@0:             ResponseHandler<? extends T> responseHandler)
michael@0:         throws IOException, ClientProtocolException;
michael@0: 
michael@0:     /**
michael@0:      * Executes a request to the target using the given context and
michael@0:      * processes the response using the given response handler.
michael@0:      *
michael@0:      * @param target    the target host for the request.
michael@0:      *                  Implementations may accept <code>null</code>
michael@0:      *                  if they can still determine a route, for example
michael@0:      *                  to a default target or by inspecting the request.
michael@0:      * @param request   the request to execute
michael@0:      * @param responseHandler the response handler
michael@0:      * @param context   the context to use for the execution, or
michael@0:      *                  <code>null</code> to use the default context
michael@0:      *
michael@0:      * @return  the response object as generated by the response handler.
michael@0:      * @throws IOException in case of a problem or the connection was aborted
michael@0:      * @throws ClientProtocolException in case of an http protocol error
michael@0:      */
michael@0:     <T> T execute(
michael@0:             HttpHost target,
michael@0:             HttpRequest request,
michael@0:             ResponseHandler<? extends T> responseHandler,
michael@0:             HttpContext context)
michael@0:         throws IOException, ClientProtocolException;
michael@0: 
michael@0: }