HttpClientFactory

import android.content.Context;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager.NameNotFoundException;
import android.os.Build;

import org.apache.http.HttpVersion;
import org.apache.http.client.HttpClient;
import org.apache.http.conn.params.ConnManagerParams;
import org.apache.http.params.CoreProtocolPNames;
import org.apache.http.params.HttpParams;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

/**
 * Constructs {@link HttpClient} instances and isolates client code from API
 * level differences.
 */
public final class HttpClientFactory {
    // TODO: migrate GDataClient to use this util method instead of apache's
    // DefaultHttpClient.
    /**
     * Creates an HttpClient with the userAgent string constructed from the
     * package name contained in the context.
     * @return the client
     */
    public static HttpClient newHttpClient(Context context) {
        return HttpClientFactory.newHttpClient(getUserAgent(context));
    }

    /**
     * Creates an HttpClient with the specified userAgent string.
     * @param userAgent the userAgent string
     * @return the client
     */
    public static HttpClient newHttpClient(String userAgent) {
        // AndroidHttpClient is available on all platform releases,
        // but is hidden until API Level 8
        try {
            Class<?> clazz = Class.forName("android.net.http.AndroidHttpClient");
            Method newInstance = clazz.getMethod("newInstance", String.class);
            Object instance = newInstance.invoke(null, userAgent);

            HttpClient client = (HttpClient) instance;

            // ensure we default to HTTP 1.1
            HttpParams params = client.getParams();
            params.setParameter(CoreProtocolPNames.PROTOCOL_VERSION, HttpVersion.HTTP_1_1);

            // AndroidHttpClient sets these two parameters thusly by default:
            // HttpConnectionParams.setSoTimeout(params, 60 * 1000);
            // HttpConnectionParams.setConnectionTimeout(params, 60 * 1000);

            // however it doesn't set this one...
            ConnManagerParams.setTimeout(params, 60 * 1000);

            return client;
        } catch (InvocationTargetException e) {
            throw new RuntimeException(e);
        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        } catch (NoSuchMethodException e) {
            throw new RuntimeException(e);
        } catch (IllegalAccessException e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * Closes an HttpClient.
     */
    public static void close(HttpClient client) {
        // AndroidHttpClient is available on all platform releases,
        // but is hidden until API Level 8
        try {
            Class<?> clazz = client.getClass();
            Method method = clazz.getMethod("close", (Class<?>[]) null);
            method.invoke(client, (Object[]) null);
        } catch (InvocationTargetException e) {
            throw new RuntimeException(e);
        } catch (NoSuchMethodException e) {
            throw new RuntimeException(e);
        } catch (IllegalAccessException e) {
            throw new RuntimeException(e);
        }
    }

    private static String sUserAgent = null;

    private static String getUserAgent(Context context) {
        if (sUserAgent == null) {
            PackageInfo pi;
            try {
                pi = context.getPackageManager().getPackageInfo(
                        context.getPackageName(), 0);
            } catch (NameNotFoundException e) {
                throw new IllegalStateException("getPackageInfo failed");
            }
            sUserAgent = String.format("%s/%s; %s/%s/%s/%s; %s/%s/%s",
                    pi.packageName,
                    pi.versionName,
                    Build.BRAND,
                    Build.DEVICE,
                    Build.MODEL,
                    Build.ID,
                    Build.VERSION.SDK_INT,
                    Build.VERSION.RELEASE,
                    Build.VERSION.INCREMENTAL);
        }
        return sUserAgent;
    }

    private HttpClientFactory() {
    }
}