使用SharedPreferences实现登录会话异常：登录后跳转回登录页

Hey there, I can spot the exact issue causing your login session to not stick—you're using the wrong key when saving the login state in your SessionManager class!

The Root Problem #

In your createSession method, you're storing the login status using the PREF_NAME constant (which is "LOGIN"):

editor.putBoolean(PREF_NAME, true);

But in your isLoggedIn method, you're checking for the LOGIN constant (which is "IS_LOGIN"):

return sharedPreferences.getBoolean(LOGIN, false);

These are two completely different keys, so the isLoggedIn method always returns false—that's why your MainActivity immediately redirects back to LoginActivity right after login.

The Fix #

Update the createSession method to use the LOGIN constant instead of PREF_NAME when setting the login status:

public void createSession(String name, String email, String type){
    // Replace PREF_NAME with LOGIN here
    editor.putBoolean(LOGIN, true);
    editor.putString(NAME, name);
    editor.putString(EMAIL, email);
    editor.putString(TYPE, type);
    editor.apply();
}

Bonus: A Minor Safety Improvement #

In your checkLoggin (quick typo note: should be checkLogin) method, you're casting context directly to MainActivity:

((MainActivity) context).finish();

If you ever use this method from a different activity later, this will cause a crash. To make it more robust, add a check first:

public void checkLoggin(){
    if (!this.isLoggedIn()){
        Intent i = new Intent(context, LoginActivity.class);
        context.startActivity(i);
        // Check if context is an Activity before casting
        if (context instanceof Activity) {
            ((Activity) context).finish();
        }
    }
}

That should fix the immediate redirect issue—your session will now persist correctly, and isLoggedIn will return true after you call createSession.

内容的提问来源于stack exchange，提问作者courage