如何在android中维护会话？

Question

Can anybody tell me how to maintain session for a user login. For example when the user sign- in to an application they have to be signed in unless the user logouts or uninstall the application similar to gmail in android.

Answer 1

Make one class for your SharedPreferences

public class Session {

    private SharedPreferences prefs;

    public Session(Context cntx) {
        // TODO Auto-generated constructor stub
        prefs = PreferenceManager.getDefaultSharedPreferences(cntx);
    }

    public void setusename(String usename) {
        prefs.edit().putString("usename", usename).commit();
    }

    public String getusename() {
        String usename = prefs.getString("usename","");
        return usename;
    }
}

Now after making this class when you want to use it, use like this: make object of this class like

private Session session;//global variable 
session = new Session(cntx); //in oncreate 
//and now we set sharedpreference then use this like

session.setusename("USERNAME");

now whenever you want to get the username then same work is to be done for session object and call this

session.getusename();

Do same for password

Answer 2

You can achieve this by using AccountManager .

Code Sample

// method to add account..
private void addAccount(String username, String password) {
    AccountManager accnt_manager = AccountManager
            .get(getApplicationContext());

    Account[] accounts = accnt_manager
            .getAccountsByType(getString(R.string.account_type)); // account name identifier.

    if (accounts.length > 0) {
        return;
    }

    final Account account = new Account(username,
            getString(R.string.account_type));

    accnt_manager.addAccountExplicitly(account, password, null);

    final Intent intent = new Intent();
    intent.putExtra(AccountManager.KEY_ACCOUNT_NAME, username);
    intent.putExtra(AccountManager.KEY_PASSWORD, password);
    intent.putExtra(AccountManager.KEY_ACCOUNT_TYPE,
            getString(R.string.account_type));
    // intent.putExtra(AccountManager.KEY_AUTH_TOKEN_LABEL,
    // PARAM_AUTHTOKEN_TYPE);
    intent.putExtra(AccountManager.KEY_AUTHTOKEN, "token");
    this.setAccountAuthenticatorResult(intent.getExtras());
    this.setResult(RESULT_OK, intent);
    this.finish();
}

// method to retrieve account.
private boolean validateAccount() {
    AccountManagerCallback<Bundle> callback = new AccountManagerCallback<Bundle>() {

        @Override
        public void run(AccountManagerFuture<Bundle> arg0) {
            Log.e("calback", "msg");

            try {
                Bundle b = arg0.getResult();
                if (b.getBoolean(AccountManager.KEY_ACCOUNT_MANAGER_RESPONSE)) {
                    //User account exists!!..
                }    
            } catch (OperationCanceledException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (AuthenticatorException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    };

    AccountManager accnt_manager = AccountManager
            .get(getApplicationContext());

    Account[] accounts = accnt_manager
            .getAccountsByType(getString(R.string.account_type));

    if (accounts.length <= 0) {
        return false;
    } else {
        loginNameVal = accounts[0].name;
        loginPswdVal = accnt_manager.getPassword(accounts[0]);
        return true;
    }
}

Answer 3

You can use a boolean value in the SharedPreferences.

Load it before login to check if login is needed.

Save it after login.

Answer 4

I have one simple way rather than maintain a session.

ie Just store one boolean variable with your username and password. by default set value equal to false.

After first successful login make its value to true.

Then just check its value on your Mainactivity, if it is true then jump to next activity otherwise jump to login activity.

Answer 5

Use following code.

SessionManager.java

public class SessionManager {
    // Shared Preferences
    SharedPreferences pref;

    // Editor for Shared preferences
    Editor editor;

    // Context
    Context _context;

    // Shared pref mode
    int PRIVATE_MODE = 0;

    // Sharedpref file name
    private static final String PREF_NAME = "Pref";

    // All Shared Preferences Keys
    private static final String IS_LOGIN = "IsLoggedIn";

    // User name (make variable public to access from outside)
    public static final String KEY_NAME = "name";

    // Email address (make variable public to access from outside)
    public static final String KEY_EMAIL = "email";

    // Constructor
    public SessionManager(Context context){
        this._context = context;
        pref = _context.getSharedPreferences(PREF_NAME, PRIVATE_MODE);
        editor = pref.edit();
    }

    /**
     * Create login session
     * */
    public void createLoginSession(String name, String email){
        // Storing login value as TRUE
        editor.putBoolean(IS_LOGIN, true);

        // Storing name in pref
        editor.putString(KEY_NAME, name);

        // Storing email in pref
        editor.putString(KEY_EMAIL, email);

        // commit changes
        editor.commit();
    }   

    /**
     * Check login method wil check user login status
     * If false it will redirect user to login page
     * Else won't do anything
     * */
    public void checkLogin(){
        // Check login status
        if(!this.isLoggedIn()){
            // user is not logged in redirect him to Login Activity
            Intent i = new Intent(_context, LoginActivity.class);
            // Closing all the Activities
            i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);

            // Add new Flag to start new Activity
            i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

            // Staring Login Activity
            _context.startActivity(i);
        }

    }



    /**
     * Get stored session data
     * */
    public HashMap<String, String> getUserDetails(){
        HashMap<String, String> user = new HashMap<String, String>();
        // user name
        user.put(KEY_NAME, pref.getString(KEY_NAME, null));

        // user email id
        user.put(KEY_EMAIL, pref.getString(KEY_EMAIL, null));

        // return user
        return user;
    }

    /**
     * Clear session details
     * */
    public void logoutUser(){
        // Clearing all data from Shared Preferences
        editor.clear();
        editor.commit();

        // After logout redirect user to Loing Activity
        Intent i = new Intent(_context, LoginActivity.class);
        // Closing all the Activities
        i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);

        // Add new Flag to start new Activity
        i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

        // Staring Login Activity
        _context.startActivity(i);
    }

    /**
     * Quick check for login
     * **/
    // Get Login State
    public boolean isLoggedIn(){
        return pref.getBoolean(IS_LOGIN, false);
    }
}

And in MainActivity do like the following.

public class MainActivity extends Activity {

    // Email, password edittext
    EditText txtUsername, txtPassword;

    // login button
    Button btnLogin;

    // Alert Dialog Manager
    AlertDialogManager alert = new AlertDialogManager();

    // Session Manager Class
    SessionManager session;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login); 

        // Session Manager
        session = new SessionManager(getApplicationContext());                

        // Email, Password input text
        txtUsername = (EditText) findViewById(R.id.txtUsername);
        txtPassword = (EditText) findViewById(R.id.txtPassword); 

        Toast.makeText(getApplicationContext(), "User Login Status: " + session.isLoggedIn(), Toast.LENGTH_LONG).show();


        // Login button
        btnLogin = (Button) findViewById(R.id.btnLogin);


        // Login button click event
        btnLogin.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View arg0) {
                // Get username, password from EditText
                String username = txtUsername.getText().toString();
                String password = txtPassword.getText().toString();

                // Check if username, password is filled                
                if(username.trim().length() > 0 && password.trim().length() > 0){
                    // For testing puspose username, password is checked with sample data
                    // username = test
                    // password = test
                    if(username.equals("test") && password.equals("test")){

                        // Creating user login session
                        // For testing i am stroing name, email as follow
                        // Use user real data
                        session.createLoginSession("ABC", "abc@gmail.com");

                        // Staring MainActivity
                        Intent i = new Intent(getApplicationContext(), MainActivity.class);
                        startActivity(i);
                        finish();

                    }else{
                        // username / password doesn't match
                        alert.showAlertDialog(LoginActivity.this, "Login failed..", "Username/Password is incorrect", false);
                    }               
                }else{
                    // user didn't entered username or password
                    // Show alert asking him to enter the details
                    alert.showAlertDialog(LoginActivity.this, "Login failed..", "Please enter username and password", false);
                }

            }
        });
    }        
}

Answer 6

Use SharedPreferences. Code to save a value to sharedpreferences:

SharedPreferences sp=getSharedPreferences("key", Context.MODE_PRIVATE);
SharedPreferences.Editor ed=sp.edit();
ed.putInt("value", your_value);
ed.commit();

Code to get value from sharedpreferences:

SharedPreferences sp=getSharedPreferences("key", Context.MODE_PRIVATE);
int value = sp.getInt("value", default_value);

You can check login and logout by using this value.

Answer 7

You can obtain that behaivour in a few different ways, the one I prefer is setting a flag in the shared prefs. whe a user logs in an check it when the app is started if you get the default value the user is not loggend, else you should have your flag (i use the user name) set and avoid the log-in section.

Answer 8

save the user data in shared preferences till the user logs out. once user logs out clear the data from shared preferences.

Answer 9

public class Session {

    private SharedPreferences prefs;

    public Session(Context cntx) {
        // TODO Auto-generated constructor stub
        prefs = PreferenceManager.getDefaultSharedPreferences(cntx);
        editor = prefs.edit();
    }

    public void setusename(String usename) {
        editor.putString("usename", usename).commit();

    }

    public String getusename() {
        String usename = prefs.getString("usename","");
        return usename;
    }
}

Answer 10

Source Code

https://drive.google.com/open?id=0BzBKpZ4nzNzUcUZxeHo0UnJ5UHc

Fetch Previous Login ID in android

**After Login save Email ID is SharedPreferences** 

    emaidId = et_Email.getText().toString().trim();

    SharedPreferences ss = getSharedPreferences("loginSession_key", 0);
    Set<String> hs = ss.getStringSet("set", new HashSet<String>());
    hs.add(emaidId);
    SharedPreferences.Editor edit = ss.edit();
    edit.clear();
    edit.putStringSet("set", hs);
    edit.commit();

===================onCreate()====================
===================AutoCompleteTextView set Adapter===================

**Fetch PRevious Login Email id in email EditText**

SharedPreferences sss = getSharedPreferences("loginSession_key", 0);            // todo loginSession_key   key name ALWAYS SAME
Log.i("chauster", "2.set = " + sss.getStringSet("set", new HashSet<String>()));
Log.e("Session", "Value->" + sss.getStringSet("set", new HashSet<String()));
ArrayList<String> al = new ArrayList<>();
al.addAll(sss.getStringSet("set", new HashSet<String>()));
//Creating the instance of ArrayAdapter containing list of language names
ArrayAdapter<String> adapter = new ArrayAdapter<String>
                (this, android.R.layout.select_dialog_item, al);
//Getting the instance of AutoCompleteTextView
et_Email.setThreshold(1);//will start working from first character
et_Email.setAdapter(adapter);//setting the adapter data into the 

Answer 11

Using this class will help you to store all types of sessions

public class Session {

    private SharedPreferences prefs;

    public Session(Context cntx) {
        // TODO Auto-generated constructor stub
        prefs = PreferenceManager.getDefaultSharedPreferences(cntx);
    }

    public void set(String key,String value) {
        prefs.edit().putString(key, value).commit();
    }

    public String get(String key) {
        String value = prefs.getString(key,"");
        return value;
    }
}