How to save and load data to/from cache when relaunching an app on Android?

Question:

Do you have any useful links on this topic? I understand that I will need to create a database in SQlite in the application, enter data there. But how to proceed further? How can I display them from the cache, and not "download" again?

Answer:

It is not clear from the question how much data (variables, arrays) should be saved when exiting the application?!

If there is not much data, then you can use the mechanism: "SharedPreferences":

Assignment of variables to save:

static final String SAVE_USERID = "save_userid";
static final String SAVE_PASSWORD = "save_password";
public static String un = "MyName", pw = "MyPassword";

Save method:

public void saveSettings() {
    SharedPreferences.Editor ed = getSharedPreferences("setting",MODE_PRIVATE).edit();
    ed.putString(SAVE_USERID, un);
    ed.putString(SAVE_PASSWORD, pw);
    ed.commit();
}

Recovery method:

public void loadSettings() {
    un = getSharedPreferences("setting",MODE_PRIVATE).getString(SAVE_USERID, "");
    pw = getSharedPreferences("setting",MODE_PRIVATE).getString(SAVE_PASSWORD, "");
}

If there is a lot of data, then work with the database is necessary.