android HttpClient,DefaultHttpClient,AbstractHttpClient之间关系

/*
* $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk/module-client/src/main/java/org/apache/http/impl/client/DefaultHttpClient.java $
* $Revision: 677250 $
* $Date: 2008-07-16 04:45:47 -0700 (Wed, 16 Jul 2008) $
*
* ====================================================================
* 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 org.apache.http.ConnectionReuseStrategy;
import org.apache.http.HttpVersion;
import org.apache.http.auth.AuthSchemeRegistry;
import org.apache.http.client.AuthenticationHandler;
import org.apache.http.client.CookieStore;
import org.apache.http.client.CredentialsProvider;
import org.apache.http.client.HttpRequestRetryHandler;
import org.apache.http.client.RedirectHandler;
import org.apache.http.client.UserTokenHandler;
import org.apache.http.client.params.AuthPolicy;
import org.apache.http.client.params.ClientPNames;
import org.apache.http.client.params.CookiePolicy;
import org.apache.http.client.protocol.ClientContext;
import org.apache.http.client.protocol.RequestAddCookies;
import org.apache.http.client.protocol.RequestDefaultHeaders;
import org.apache.http.client.protocol.RequestProxyAuthentication;
import org.apache.http.client.protocol.RequestTargetAuthentication;
import org.apache.http.client.protocol.ResponseProcessCookies;
import org.apache.http.conn.ClientConnectionManager;
import org.apache.http.conn.ClientConnectionManagerFactory;
import org.apache.http.conn.ConnectionKeepAliveStrategy;
import org.apache.http.conn.routing.HttpRoutePlanner;
import org.apache.http.conn.scheme.PlainSocketFactory;
import org.apache.http.conn.scheme.Scheme;
import org.apache.http.conn.scheme.SchemeRegistry;
import org.apache.http.conn.ssl.SSLSocketFactory;
import org.apache.http.cookie.CookieSpecRegistry;
import org.apache.http.impl.DefaultConnectionReuseStrategy;
import org.apache.http.impl.auth.BasicSchemeFactory;
import org.apache.http.impl.auth.DigestSchemeFactory;
import org.apache.http.impl.conn.DefaultHttpRoutePlanner;
import org.apache.http.impl.conn.SingleClientConnManager;
import org.apache.http.impl.cookie.BestMatchSpecFactory;
import org.apache.http.impl.cookie.BrowserCompatSpecFactory;
import org.apache.http.impl.cookie.NetscapeDraftSpecFactory;
import org.apache.http.impl.cookie.RFC2109SpecFactory;
import org.apache.http.impl.cookie.RFC2965SpecFactory;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpParams;
import org.apache.http.params.HttpProtocolParams;
import org.apache.http.protocol.BasicHttpContext;
import org.apache.http.protocol.BasicHttpProcessor;
import org.apache.http.protocol.HTTP;
import org.apache.http.protocol.HttpContext;
import org.apache.http.protocol.HttpRequestExecutor;
import org.apache.http.protocol.RequestConnControl;
import org.apache.http.protocol.RequestContent;
import org.apache.http.protocol.RequestExpectContinue;
import org.apache.http.protocol.RequestTargetHost;
import org.apache.http.protocol.RequestUserAgent;
import org.apache.http.util.VersionInfo;

/**
* Default implementation of an HTTP client.
* <br/>
* This class replaces <code>HttpClient</code> in HttpClient 3.
*
* @author <a href="mailto:rolandw at apache.org">Roland Weber</a>
* @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a>
*
* <!-- empty lines to avoid svn diff problems -->
* @version   $Revision: 677250 $
*
* @since 4.0
*/
public class DefaultHttpClient extends AbstractHttpClient {

/**
* Creates a new HTTP client from parameters and a connection manager.
*
* @param params    the parameters
* @param conman    the connection manager
*/
public DefaultHttpClient(
final ClientConnectionManager conman,
final HttpParams params) {
super(conman, params);
}

public DefaultHttpClient(final HttpParams params) {
super(null, params);
}

public DefaultHttpClient() {
super(null, null);
}

@Override
protected HttpParams createHttpParams() {
HttpParams params = new BasicHttpParams();
HttpProtocolParams.setVersion(params,
HttpVersion.HTTP_1_1);
HttpProtocolParams.setContentCharset(params,
HTTP.DEFAULT_CONTENT_CHARSET);

/*
* Android note: Send each request body without first asking the server
* whether it will be accepted. Asking first slows down the common case
* and results in "417 expectation failed" errors when a HTTP/1.0 server
* is behind a proxy. http://b/2471595 */
HttpProtocolParams.setUseExpectContinue(params,
false); // android-changed

// determine the release version from packaged version info
final VersionInfo vi = VersionInfo.loadVersionInfo
("org.apache.http.client", getClass().getClassLoader());
final String release = (vi != null) ?
vi.getRelease() : VersionInfo.UNAVAILABLE;
HttpProtocolParams.setUserAgent(params,
"Apache-HttpClient/" + release + " (java 1.4)");

return params;
}

@Override
protected HttpRequestExecutor createRequestExecutor() {
return new HttpRequestExecutor();
}

@Override
protected ClientConnectionManager createClientConnectionManager() {
SchemeRegistry registry = new SchemeRegistry();
registry.register(
new Scheme("http", PlainSocketFactory.getSocketFactory(), 80));
registry.register(
new Scheme("https", SSLSocketFactory.getSocketFactory(), 443));

ClientConnectionManager connManager = null;
HttpParams params = getParams();

ClientConnectionManagerFactory factory = null;

// Try first getting the factory directly as an object.
factory = (ClientConnectionManagerFactory) params
.getParameter(ClientPNames.CONNECTION_MANAGER_FACTORY);
if (factory == null) { // then try getting its class name.
String className = (String) params.getParameter(
ClientPNames.CONNECTION_MANAGER_FACTORY_CLASS_NAME);
if (className != null) {
try {
Class<?> clazz = Class.forName(className);
factory = (ClientConnectionManagerFactory) clazz.newInstance();
} catch (ClassNotFoundException ex) {
throw new IllegalStateException("Invalid class name: " + className);
} catch (IllegalAccessException ex) {
throw new IllegalAccessError(ex.getMessage());
} catch (InstantiationException ex) {
throw new InstantiationError(ex.getMessage());
}
}
}

if(factory != null) {
connManager = factory.newInstance(params, registry);
} else {
connManager = new SingleClientConnManager(getParams(), registry);
}

return connManager;
}

@Override
protected HttpContext createHttpContext() {
HttpContext context = new BasicHttpContext();
context.setAttribute(
ClientContext.AUTHSCHEME_REGISTRY,
getAuthSchemes());
context.setAttribute(
ClientContext.COOKIESPEC_REGISTRY,
getCookieSpecs());
context.setAttribute(
ClientContext.COOKIE_STORE,
getCookieStore());
context.setAttribute(
ClientContext.CREDS_PROVIDER,
getCredentialsProvider());
return context;
}

@Override
protected ConnectionReuseStrategy createConnectionReuseStrategy() {
return new DefaultConnectionReuseStrategy();
}

@Override
protected ConnectionKeepAliveStrategy createConnectionKeepAliveStrategy() {
return new DefaultConnectionKeepAliveStrategy();
}

@Override
protected AuthSchemeRegistry createAuthSchemeRegistry() {
AuthSchemeRegistry registry = new AuthSchemeRegistry();
registry.register(
AuthPolicy.BASIC,
new BasicSchemeFactory());
registry.register(
AuthPolicy.DIGEST,
new DigestSchemeFactory());
return registry;
}

@Override
protected CookieSpecRegistry createCookieSpecRegistry() {
CookieSpecRegistry registry = new CookieSpecRegistry();
registry.register(
CookiePolicy.BEST_MATCH,
new BestMatchSpecFactory());
registry.register(
CookiePolicy.BROWSER_COMPATIBILITY,
new BrowserCompatSpecFactory());
registry.register(
CookiePolicy.NETSCAPE,
new NetscapeDraftSpecFactory());
registry.register(
CookiePolicy.RFC_2109,
new RFC2109SpecFactory());
registry.register(
CookiePolicy.RFC_2965,
new RFC2965SpecFactory());
return registry;
}

@Override
protected BasicHttpProcessor createHttpProcessor() {
BasicHttpProcessor httpproc = new BasicHttpProcessor();
httpproc.addInterceptor(new RequestDefaultHeaders());
// Required protocol interceptors
httpproc.addInterceptor(new RequestContent());
httpproc.addInterceptor(new RequestTargetHost());
// Recommended protocol interceptors
httpproc.addInterceptor(new RequestConnControl());
httpproc.addInterceptor(new RequestUserAgent());
httpproc.addInterceptor(new RequestExpectContinue());
// HTTP state management interceptors
httpproc.addInterceptor(new RequestAddCookies());
httpproc.addInterceptor(new ResponseProcessCookies());
// HTTP authentication interceptors
httpproc.addInterceptor(new RequestTargetAuthentication());
httpproc.addInterceptor(new RequestProxyAuthentication());
return httpproc;
}

@Override
protected HttpRequestRetryHandler createHttpRequestRetryHandler() {
return new DefaultHttpRequestRetryHandler();
}

@Override
protected RedirectHandler createRedirectHandler() {
return new DefaultRedirectHandler();
}

@Override
protected AuthenticationHandler createTargetAuthenticationHandler() {
return new DefaultTargetAuthenticationHandler();
}

@Override
protected AuthenticationHandler createProxyAuthenticationHandler() {
return new DefaultProxyAuthenticationHandler();
}

@Override
protected CookieStore createCookieStore() {
return new BasicCookieStore();
}

@Override
protected CredentialsProvider createCredentialsProvider() {
return new BasicCredentialsProvider();
}

@Override
protected HttpRoutePlanner createHttpRoutePlanner() {
return new DefaultHttpRoutePlanner
(getConnectionManager().getSchemeRegistry());
}

@Override
protected UserTokenHandler createUserTokenHandler() {
return new DefaultUserTokenHandler();
}

} // class DefaultHttpClient