(1)采用单例模式(重用HttpClient实例)
对于一个通信单元甚至是整个应用程序,Apache强烈推荐只使用一个HttpClient的实例。例如:
private static HttpClient httpClient = null;
private static synchronized HttpClient getHttpClient() {
if(httpClient == null) {
final HttpParams httpParams = new BasicHttpParams();
httpClient = new DefaultHttpClient(httpParams);
}
return httpClient;
}
(2)保持连接(重用连接)
对于已经和服务端建立了连接的应用来说,再次调用HttpClient进行网络数据传输时,就不必重新建立新连接了,而可以重用已经建立的连接。这样无疑可以减少开销,提升速度。
在这个方面,Apache已经做了“连接管理”,默认情况下,就会尽可能的重用已有连接,因此,不需要客户端程序员做任何配置。只是需要注意,Apache的连接管理并不会主动释放建立的连接,需要程序员在不用的时候手动关闭连接。
(3)多线程安全管理的配置
如果应用程序采用了多线程进行网络访问,则应该使用Apache封装好的线程安全管理类ThreadSafeClientConnManager来进行管理,这样能够更有效且更安全的管理多线程和连接池中的连接。
);
// timeout: connect to the server
HttpConnectionParams.setConnectionTimeout(httpParams, DEFAULT_SOCKET_TIMEOUT);
// timeout: transfer data from server
HttpConnectionParams.setSoTimeout(httpParams, DEFAULT_SOCKET_TIMEOUT);
// set max connections per host
ConnManagerParams.setMaxConnectionsPerRoute(httpParams, new ConnPerRouteBean(DEFAULT_HOST_CONNECTIONS));
// set max total connections
ConnManagerParams.setMaxTotalConnections(httpParams, DEFAULT_MAX_CONNECTIONS);
// use expect-continue handshake
HttpProtocolParams.setUseExpectContinue(httpParams, true);
// disable stale check
HttpConnectionParams.setStaleCheckingEnabled(httpParams, false);
HttpProtocolParams.setVersion(httpParams, HttpVersion.HTTP_1_1);
HttpProtocolParams.setContentCharset(httpParams, HTTP.UTF_8);
HttpClientParams.setRedirecting(httpParams, false);
// set user agent
String userAgent = "Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN; rv:1.9.2) Gecko/20100115 Firefox/3.6";
HttpProtocolParams.setUserAgent(httpParams, userAgent);
// disable Nagle algorithm
HttpConnectionParams.setTcpNoDelay(httpParams, true);
HttpConnectionParams.setSocketBufferSize(httpParams, DEFAULT_SOCKET_BUFFER_SIZE);
// scheme: http and https
SchemeRegistry schemeRegistry = new SchemeRegistry();
schemeRegistry.register(new Scheme("http", PlainSocketFactory.getSocketFactory(), 80));
schemeRegistry.register(new Scheme("https", SSLSocketFactory.getSocketFactory(), 443));
ClientConnectionManager manager = new ThreadSafeClientConnManager(httpParams, schemeRegistry);
httpClient = new DefaultHttpClient(manager, httpParams);
}
return httpClient;
}