android sharedpreferences map,java - android SharedPreferences and Map - Stack Overflow

短命女 2022-10-05 09:54 158阅读 0赞

In my app I save some user information (i.e. name, weight, height) as key-value-pairs using SharedPreferences.

These information are used in several activities. So I thought, instead of implementing the whole procedure for reading/writing to the SharedPreferences in each activity, I also could implement a class "UserData" and define several static methods. So when I need some user information or want to save them I only use methods of the class "UserData" and this class handles all the stuff in background.

So I did the following things:

class UserData contains a private Map

this map is filled by the getAll()-Method of SharedPreferences

initialization is triggerd in the onCreate()-Method in each activity

providing the values (for each possible type) to a defined key is done by the getValue(String key)-Method

writing (new) information should be done by setter methods

to write back to shared preferences, there is a save function

But now I have a lot of questions:

getAll() method

I expect, that getAll() will read all key-value-pairs from the SharedPreferences. So I would expect, that after initialization data will contain (String,String)-pairs (i.e. "name";"Max") as well as (String,Integer)-pairs (i.e. "weight",85). Am I right?

getting the values

Is the way, how I return the values in getValue(String key) correct? How can I get the value type from such a Map or Map.Entry definition?

adding Entries to the map

I have no idea how to overwrite or write new entries to data. One Idea was, to create a set-method for each type (i.e. String, Integer) I can save in SharedPreferences, create an Entry within this method and then calling an add-method. But how should this looks like?

saving

Will this saving fuction work properly? I'm not realy sure.

Or is this a total stupid approach?

Thanks for your support.

This is my UserData-class

public class UserData \{

static private boolean isInit = false;

static private Map data = new HashMap<>();

static void initialize(Context context)\{

if(UserData.isInit)\{

return;

if(context==null)\{