Collection of code to use the Client interface of Retrofit to use HttpUrlConnection with SharedPreferences persistent cookies.

AndroidCookieStore.java

import android.annotation.TargetApi;
import android.content.SharedPreferences;
import android.os.Build;
import android.os.PatternMatcher;
import com.keepandshare.android.utils.CryptographyUtil;
import com.keepandshare.android.utils.Ln;

import javax.inject.Singleton;
import java.net.CookieStore;
import java.net.HttpCookie;
import java.net.URI;
import java.util.List;

import static com.google.common.collect.Lists.newArrayList;
import static com.keepandshare.android.utils.SharedPreferencesCompat.apply;

/**
 * A simple {@linkplain CookieStore cookie jar} that only cares to store the {@link #_COOKIE_AUTH_TOKEN}.
 * It persists the cookie through app launches and maintains it securely.
 * @author Dandré Allison
 */
@Singleton
@TargetApi(Build.VERSION_CODES.GINGERBREAD)
public class AndroidCookieStore implements CookieStore {

/* Constructor */
    public AndroidCookieStore(SharedPreferences settings, CryptographyUtil crypto) {
        _settings = settings;
        _crypto = crypto;
    }

/* Cookie Store */
    @Override
    public void add(URI _, HttpCookie cookie) {
        Ln.v("Adding Cookie: %s", cookie);

        // Stores the cookie in shared preferences
        if (_auth_token_pattern.match(cookie.getName())) {
            final SharedPreferences.Editor editor = _settings.edit();
            try {
                editor.putString(_KEY_AUTH_TOKEN, _crypto.encrypt(cookie.getValue()));
            } catch (Exception error) {
                Ln.e(error.getCause());
            }
            apply(editor);
        }
    }

    @Override
    public List<HttpCookie> getCookies() {
        return get(null);
    }

    @Override
    public List<HttpCookie> get(URI _) {
        // Loads in cookies from shared preferences
        final String auth_token = _settings.getString(_KEY_AUTH_TOKEN, null);
        if (auth_token != null)
            try {
                final HttpCookie cookie = new HttpCookie(_COOKIE_AUTH_TOKEN, _crypto.decrypt(auth_token));
                cookie.setPath("/");
                cookie.setVersion(0);
                Ln.v("Retrieved Cookie: %s", cookie);
                return newArrayList(cookie);
            } catch (Exception error) {
                Ln.e(error.getCause());
            }
        return newArrayList();
    }

    @Override
    public List<URI> getURIs() {
        return newArrayList();
    }

    @Override
    public boolean remove(URI _, HttpCookie __) {
        final boolean had_auth_token = _settings.getString(_KEY_AUTH_TOKEN, null) != null;
        final SharedPreferences.Editor editor = _settings.edit();
        apply(editor.remove(_KEY_AUTH_TOKEN));
        return had_auth_token;
    }

    @Override
    public boolean removeAll() {
        return remove(null,null);
    }

    private static final String _KEY_AUTH_TOKEN = "AUTH_TOKEN";
    private static final String _COOKIE_AUTH_TOKEN = "PHPSESSID";
    private static final PatternMatcher _auth_token_pattern = new PatternMatcher(_COOKIE_AUTH_TOKEN, PatternMatcher.PATTERN_LITERAL);
    private final SharedPreferences _settings;
    private final CryptographyUtil _crypto;
}

RecommendedAndroidClient.java

import android.os.PatternMatcher;
import com.github.kevinsawicki.http.HttpRequest;
import com.keepandshare.android.utils.CircularByteBuffer;
import com.keepandshare.android.utils.Ln;
import org.apache.http.protocol.HttpContext;
import retrofit.http.Header;
import retrofit.http.client.Client;
import retrofit.http.client.Request;
import retrofit.http.client.Response;
import retrofit.http.mime.TypedInput;
import retrofit.http.mime.TypedOutput;

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import static com.google.common.collect.Maps.newHashMap;

/**
 * Custom implementation of {@link Client} that can utilize an {@link HttpContext}.
 * @author Dandré Allison
 */
public class RecommendedAndroidClient implements Client {

    @Override
    public Response execute(Request request) throws IOException {
        Ln.v("Request: %s '%s'", request.getMethod(), _sanitize_passwords.reset(request.getUrl()).replaceAll("p=***"));
        // Creates the request
        final HttpRequest http_response = new HttpRequest(request.getUrl(), request.getMethod())
                // Requests compressed responses
                .acceptGzipEncoding()
                // Automatically uncompresses response
                .uncompress(true);
        prepareRequest(http_response);

        final List<Header> headers = request.getHeaders();
        if (headers != null)
            http_response.headers(prepareHeaders(request.getHeaders()));

        final TypedOutput body = request.getBody();
        if (body != null) {
            final CircularByteBuffer byte_buffer = new CircularByteBuffer(CircularByteBuffer.INFINITE_SIZE);
            request.getBody().writeTo(byte_buffer.getOutputStream());
            http_response.send(byte_buffer.getInputStream());
        }

        // Creates the response
        return parseResponse(http_response);
    }

    Response parseResponse(HttpRequest response) throws IOException {
        final InputStream stream = response.buffer();
        final int status = response.code();
        final String reason = response.message();

        final List<Header> headers = new ArrayList<Header>();
        String content_type = "application/octet-stream";
        for (Map.Entry<String, List<String>> header : response.headers().entrySet()) {
            final String name = header.getKey();
            final String value = header.getValue().get(0);
            if (_content_type_header.match(name))
                content_type = value;
            headers.add(new Header(name, value));
        }

        prepareResponse(response, stream);

        final TypedInputStream body = stream == null? null : new TypedInputStream(content_type, stream);

        return new Response(status, reason, headers, body);
    }

    /** Callback for additional preparation of the request before execution. */
    protected void prepareRequest(HttpRequest request) { }

    /** Callback for additional preparation of the response before parsing. */
    protected void prepareResponse(HttpRequest response, InputStream body) { }

    static class TypedInputStream implements TypedInput {

        public TypedInputStream(String mime_type, InputStream in) {
            _mime_type = mime_type;
            _in = new BufferedInputStream(in);
        }

        @Override
        public String mimeType() {
            return _mime_type;
        }

        @Override
        public long length() {
            return -1;
        }

        @Override
        public InputStream in() throws IOException {
            return _in;
        }

        private final String _mime_type;
        public final InputStream _in;
    }

    private Map<String, String> prepareHeaders(List<Header> headers) {
        if (headers == null) return null;
        final Map<String, String> header_map = newHashMap();
        for (Header header : headers)
            header_map.put(header.getName(), header.getValue());
        return header_map;
    }

    private static final PatternMatcher _content_type_header = new PatternMatcher(HttpRequest.HEADER_CONTENT_TYPE, PatternMatcher.PATTERN_LITERAL);
    private static final Matcher _sanitize_passwords = Pattern.compile("(p=)[^&]*").matcher("");
}

Snippets

// Sets the AndroidCookieStore as the CookieStore to use for managing magic-cookies
final CookieManager cookie_manager = new CookieManager(cookie_jar, CookiePolicy.ACCEPT_ORIGINAL_SERVER);
CookieHandler.setDefault(new CookieManager());

// Configures the RestAdapter to use RecommendedAndroidClient instead of AndroidHttpClient
RestAdapter rest_adapter = new RestAdapter.Builder().setServer("http://www.example.com)
                .setClient(http_client).build();

Where can I get the code for com.keepandshare.android.utils.CryptographyUtil?

Thanks.

setClient(http_client) ? what is http_client, is not defined anywhere!.

Hi
I have found one good example here
Android Session Management Using SharedPreferences