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