如何在应用程序中使用共享首选项保存 JSON 对象响应

Question

public class MainActivity extends Activity implements OnPreparedListener,
    OnClickListener {

Button login;
Button register;
EditText pass_word;
EditText mail;
TextView loginErrormsg;


private static final String TAG = null;
private static String KEY_SUCCESS = "success";
private static String KEY_UID = "uid";
private static String KEY_EMAIL = "email";
private static String KEY_PASSWORD = "password";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    if (android.os.Build.VERSION.SDK_INT > 9) {
        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
                .permitAll().build();
        StrictMode.setThreadPolicy(policy);
    }
    setContentView(R.layout.activity_main);

    mail = (EditText) findViewById(R.id.email);
    pass_word = (EditText) findViewById(R.id.password);
    loginErrormsg = (TextView) findViewById(R.id.login_error);
    login = (Button) findViewById(R.id.btnlogin);
    register = (Button) findViewById(R.id.btnregister);

    login.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub

            String email = mail.getText().toString();
            String password = pass_word.getText().toString();
            UserFunctions userFunctions = new UserFunctions();
            JSONObject json = userFunctions.loginUser(email, password);
            // JSONObject userinfo = json.getJSONObject("user");

            // check for login response
            try {
                if (json.getString(KEY_SUCCESS) != null) {
                    loginErrormsg.setText("");
                    String res = json.getString(KEY_SUCCESS);


                    if (Integer.parseInt(res) == 1) {
                        Log.d("Login Successful!", json.toString());

                        // user successfully logged in
                        // Store user details in SQLite Database
                        DatabaseHandler db = new DatabaseHandler(
                                getApplicationContext());
                        JSONObject json_user = json.getJSONObject("user");

                        // Clear all previous data in database
                        userFunctions.logoutUser(getApplicationContext());
                        db.addUser(json_user.getString(KEY_EMAIL),
                                json_user.getString(KEY_PASSWORD));

                        Intent dashboard = new Intent(
                                getApplicationContext(),
                                LoginActivity.class);
                        dashboard.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                        startActivity(dashboard);

                        // Close Login Screen
                        finish();
                    } else {
                        // Error in login
                        loginErrormsg
                                .setText("Incorrect username/password");
                    }
                }
            } catch (JSONException e) {
                e.printStackTrace();
            }
        }
    });

    register.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            Intent i = new Intent(getApplicationContext(),
                    RegisterActivity.class);
            startActivity(i);

        }
    });

}

public static void setUserObject(Context c, String userObject, String key) {
    SharedPreferences pref = PreferenceManager
            .getDefaultSharedPreferences(c);
    SharedPreferences.Editor editor = pref.edit();
    editor.putString(key, userObject);
    editor.commit();
}
public static String getUserObject(Context ctx, String key) {
    SharedPreferences pref = PreferenceManager
            .getDefaultSharedPreferences(ctx);
    String userObject = pref.getString(key, null);
    return userObject;
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}
 }

这是我的服务器响应：

{
  "tag":"login",
  "success":1,
  "error":0,
  "user":{
    "email":"sridhar@gmail.com",
    "password":"7a4fb4770d2c404b0c48abd49f4c5f6a",
    "id":"118"
    }
  }

Answer 1

好吧，既然你已经在 json_user 对象中有了 id，那么就这样做：

String userId = json_user.optString("id");
if(!userId.isEmpty()) {
    getSharedPreferences(YOUR_PREFERENCE_NAME, MODE_PRIVATE).edit().putString(YOUR_USER_ID_KEY_NAME, userId).commit();
}

然后稍后检索它，使用：

String userId = getSharedPreferences(YOUR_PREFERENCE_NAME, MODE_PRIVATE).getString(YOUR_USER_ID_KEY_NAME, null);
if(userId != null) {
    //Successfully retrieved user id
}
else {
    //Id not found in preferences
}

Answer 2

如果您只想在服务器响应的共享首选项中存储 id，您可以这样做，

JSONObject jsonObject = new JSONObject("Your response from server");
JSONObject jsonObject1 = jsonObject.getJSONObject("user");
String id = jsonObject1.getString("id");

SharedPreference sp = getApplicationContext().getSharedPreferences(
            "sharedPrefName", 0); // 0 for private mode

Editor editor = sp.edit();
editor.putString("key_name",id); // key_name is the name through which you can retrieve it later.
editor.commit();


// To retrieve value from shared preference in another activity
 SharedPreference sp = getApplicationContext().getSharedPreferences(
            "sharedPrefName", 0); // 0 for private mode
String id = sp.getString("key_name","defaultvalue"); // key_name is the key you have used for store "id" in shared preference. and deafult value can be anything.

如果您的共享偏好没有给定键的任何值，则默认值为 returns，否则为键存储的值为 returns

如何在应用程序中使用共享首选项保存 JSON 对象响应

how to save JSONObject reponse using Shared Preferences in App

android

json

sharedpreferences