如何在android中维护会话？

How to maintain session in android?

提问by june

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.

谁能告诉我如何为用户登录维护会话。例如，当用户登录到一个应用程序时，他们必须登录，除非用户注销或卸载类似于 android 中的 gmail 的应用程序。

回答by Bhanu Sharma

Make one class for your SharedPreferences

为您打造一堂课 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

现在当你想使用它时创建这个类后，像这样使用：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

现在，每当您想获取用户名时，都要为会话对象完成相同的工作并调用它

session.getusename();

Do same for password

对密码执行相同操作

回答by nikvs

You can achieve this by using AccountManager.

您可以使用AccountManager.

Code Sample

代码示例

// 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;
    }
}

回答by Jitesh Dalsaniya

Use following code.

使用以下代码。

SessionManager.java

会话管理器

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.

并在 MainActivity 中执行以下操作。

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", "[email protected]");

                        // 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);
                }

            }
        });
    }        
}

回答by Phant?maxx

You can use a boolean value in the SharedPreferences.

您可以在 SharedPreferences 中使用布尔值。

Load it before login to check if login is needed.

在登录前加载它以检查是否需要登录。

Save it after login.

登录后保存。

回答by Sanket Shah

I have one simple way rather than maintain a session.

我有一种简单的方法，而不是保持会话。

i.e. Just store one booleanvariable with your username and password. by default set value equal to false.

即只boolean用您的用户名和密码存储一个变量。默认设置值等于 false。

After first successful login make its value to true.

第一次成功登录后，将其值设为 true。

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

然后只需检查它在您的 Mainactivity 上的值，如果为真，则跳转到下一个活动，否则跳转到登录活动。

回答by Shahina

Use SharedPreferences. Code to save a value to sharedpreferences:

使用共享首选项。将值保存到 sharedpreferences 的代码：

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:

从共享首选项获取值的代码：

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

You can check login and logout by using this value.

您可以使用此值检查登录和注销。

回答by Trinadh Koya

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;
    }
}

回答by Keshav Gera

Source Code

源代码

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

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

Fetch Previous Login ID in android

在android中获取以前的登录ID

**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 

回答by Nain Abbas

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

使用这个类将帮助你存储所有类型的会话

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;
    }
}

回答by Yogamurthy

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

将用户数据保存在共享首选项中，直到用户注销。一旦用户注销，从共享首选项中清除数据。