Android Asynchronous Http Client (loopj) and the P

问题:

I am new to Android Development. Had a few questions on what is the best way to make the libraries mentioned above work optimally.

Currently, I have three activities in my app. MainActivity, LoginActivity and HomeActivity. The app launches the MainActivity which is supposed to check if the person is logged in. If the person is logged in, redirect to Home, else redirect to Login.

As mentioned in the documentation, I created a RestClient class. I can successfully make a request in my LoginActivity and get a response. This is my code for the login.

public void login() {
        RequestParams params = new RequestParams();
        params.put(AUTH_PARAMETER_EMAIL, mEmail);
        params.put(AUTH_PARAMETER_PASSWORD, mPassword);

        RestClient.setCookieStore(new PersistentCookieStore(this));
        RestClient.post(AUTH_URL, params, new JsonHttpResponseHandler() {
            @Override
            public void onFinish() {
                showProgress(false);
            }

            @Override
            public void onSuccess(JSONObject response) {
                String response_status = null;
                try {
                    response_status = response.getString(AUTH_RESPONSE_STATUS);
                } catch (JSONException e) {
                    Toast.makeText(LoginActivity.this,
                            "ERROR: " + e.toString(), Toast.LENGTH_LONG).show();
                    Log.e(TAG, e.toString());
                }
                if (response_status.equals(AUTH_SUCCESS_STATUS)) {
                    finish();
                } else {
                    mPasswordView
                            .setError(getString(R.string.error_incorrect_password));
                    mPasswordView.requestFocus();
                }
            }

            @Override
            public void onFailure(Throwable e, String content) {
                Toast.makeText(LoginActivity.this, "ERROR: " + e.toString(),
                        Toast.LENGTH_LONG).show();
                Log.e(TAG, e.toString());
            }

        });
    }

Questions

1. This is going to create a new cookie store each time a request is made. Where should i put it so that it is only created once? Should i put it in the onCreate of the MainActivity and then assign it to a global variable? Is that the best practice?
2. In my MainActivity, how can I check for the session cookie that was sent from the server? I know it is in shared preferences, but how can i get it? The documentation doesnt say what variable it will be stored under in the SharedPreferences.
3. When I need to logout someone, do I delete the shared preferences or erase the cookie store or both? Are they automatically kept in sync?
4. When the app restarts, how do i initialise the cookie store from the saved data in the sharedpreferences?
5. If you know of any open-sourced code that properly implements this, Ill be happy to look at it and answer these questions myself. Just provide a link!

回答1:

So here is what I have done until now. It works, but I am not sure if it is best practice.

1) The cookie store initialises from the sharedpreference. so just create a new one each time you need it. be sure to use the same context each time. I am using getApplicationContext()

2) and 4) The cookie store handels it all for you. Just create a new one with the same context as the one you created earlier. As long as you are consistent, the cookies will initialise properly.

3) the cookie store keeps the shared preferences and its local attributes in sync so just call (new PersistentCookieStore(getApplicationContext())).clear();

My Code

RestClient.java

public static void setCookieStore(PersistentCookieStore cookieStore) {
    client.setCookieStore(cookieStore);
}

LoginActivity.java

RestClient.setCookieStore(new PersistentCookieStore(getApplicationContext()));

MainActivity.java

private void loginRouter() {
    PersistentCookieStore mCookieStore = new PersistentCookieStore(
            getApplicationContext());
    List<Cookie> cookies = mCookieStore.getCookies();
    for (Cookie c : cookies) {
        if (c.getName().equals("session")) {
            startActivity(new Intent(this, HomeActivity.class));
            finish();
        }
    }
    launchSplashPage();
}