[Android] Http Client

import org.apache.http.HttpVersion;
import org.apache.http.client.HttpClient;
import org.apache.http.conn.ClientConnectionManager;
import org.apache.http.conn.params.ConnManagerParams;
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.impl.client.DefaultHttpClient;
import org.apache.http.impl.conn.tsccm.ThreadSafeClientConnManager;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpConnectionParams;
import org.apache.http.params.HttpParams;
import org.apache.http.params.HttpProtocolParams;
import org.apache.http.protocol.HTTP;

public class CustomHttpClient {
    private static HttpClient customHttpClient;

    /** A private Constructor prevents instantiation */
    private CustomHttpClient() {
    }

    public static synchronized HttpClient getHttpClient() {
        if (customHttpClient == null) {
            HttpParams params = new BasicHttpParams();
            HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);
            HttpProtocolParams.setContentCharset(params, HTTP.DEFAULT_CONTENT_CHARSET);
            HttpProtocolParams.setUseExpectContinue(params, true);
            HttpProtocolParams.setUserAgent(params,  "Mozilla/5.0 (Linux; U; Android 2.2.1; en-us; Nexus One Build/FRG83) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1" );
            params.setParameter("charset", "UTF-8"); // 要設成utf-8，否則中文的utf-8網頁會出錯
            ConnManagerParams.setTimeout(params, 1000);

            HttpConnectionParams.setConnectionTimeout(params, 5000);
            HttpConnectionParams.setSoTimeout(params, 10000);

            SchemeRegistry schReg = new SchemeRegistry();
            schReg.register(new Scheme("http",  PlainSocketFactory.getSocketFactory(), 80));
            schReg.register(new Scheme("https", SSLSocketFactory.getSocketFactory(), 443));
            ClientConnectionManager conMgr = new ThreadSafeClientConnManager(params,schReg);
            customHttpClient = new DefaultHttpClient(conMgr, params);
        }
        return customHttpClient;
    }
}