RemoteHelper.java

package external.GifImageViewEx.net.frakbot.remote;

import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.URL;

import com.aiyou.utils.logcat.Logcat;
import com.squareup.okhttp.OkHttpClient;

/**
 * Helper class that exposes some utility methods for retrieving objects from
 * the network.
 * 
 * @author Francesco Pontillo
 */
public class RemoteHelper {
    private static final String LOG_TAG = "Loader";

    private static final int defaultBufferSize = 2048;

    /**
     * Download an object from the network.
     * 
     * @param resourceUrl The URL of then rsource.
     * @throws IOException If the connection cannot be established.
     * @return Byte array of the downloaded object.
     */
    public static byte[] download(String resourceUrl) throws IOException {
        OkHttpClient client = new OkHttpClient();
        URL url = new URL(resourceUrl);
        HttpURLConnection connection = client.open(url);

        final int responseCode = connection.getResponseCode();
        if (responseCode != HttpURLConnection.HTTP_OK) {
            Logcat.w(LOG_TAG, "Downloading from URL " + resourceUrl
                    + " failed with response code " + responseCode);
            return null;
        }

        // determine the image size and allocate a buffer
        int fileSize = connection.getContentLength();
        Logcat.d(LOG_TAG, "fetching " + resourceUrl + " ("
                + (fileSize <= 0 ? "size unknown" : Integer.toString(fileSize))
                + ")");

        BufferedInputStream istream = new BufferedInputStream(
                connection.getInputStream());

        try {
            if (fileSize <= 0) {
                Logcat.w(LOG_TAG,
                        "Server did not set a Content-Length header, will default to buffer size of "
                                + defaultBufferSize + " bytes");
                ByteArrayOutputStream buf = new ByteArrayOutputStream(
                        defaultBufferSize);
                byte[] buffer = new byte[defaultBufferSize];
                int bytesRead = 0;
                while (bytesRead != -1) {
                    bytesRead = istream.read(buffer, 0, defaultBufferSize);
                    if (bytesRead > 0) {
                        buf.write(buffer, 0, bytesRead);
                    }
                }
                return buf.toByteArray();
            } else {
                byte[] data = new byte[fileSize];

                int bytesRead = 0;
                int offset = 0;
                while (bytesRead != -1 && offset < fileSize) {
                    bytesRead = istream.read(data, offset, fileSize - offset);
                    offset += bytesRead;
                }
                return data;
            }
        } finally {
            // clean up
            try {
                istream.close();
                connection.disconnect();
            } catch (Exception ignore) {
            }
        }
    }

}