read java.util.Map from a file

Question

I'm having a problem with getting values from a map that I save into a Preferences file. I can print out the keys from the map, but not any values. I think it has something to do with the typecasting that I'm doing, but I've tried everything I know of and can't figure it out.

I tested the values from the map that I saved to the preferences file, and they output just fine.

I tried the suggestions below but they did not help

Heres my code

public class SetSettings {
private Actor actor;
private Actor hit;
private Sprite sprite;
private Sprite sprite2;
private Rectangle rect;
private boolean customHit = false;
private ShapeRenderer render = new ShapeRenderer();
public float y;
public float x;
Array<Actor> actors = GameScreen.buttons.stage.getActors();

public SetSettings() {
    setOriginal();
    setCustom();
    rect = new Rectangle();
}

public void setOriginal() {
    learnGame.ass.settings.get().clear();
    float height = Gdx.graphics.getHeight();
    float width = Gdx.graphics.getWidth();
    // ui settings
    java.util.Map<String, Coords> map = new HashMap<String, Coords>();
    map.put("hpBar", new Coords(width - (learnGame.ass.hpBar.getWidth() * 1.02f), height - (height * .076f)));
    map.put("hpBase", new Coords(learnGame.ass.hpBar.getX(), learnGame.ass.hpBar.getY()));

    for (Entry<String, Coords> key : map.entrySet())
        System.out.println(key.getValue().x); // works fine here

}

public void setCustom() {
    java.util.Map<String, Coords> amap = (java.util.HashMap<String, Coords>) learnGame.ass.settings.get();
    // Float[] nums = amap.get("hpBar");
    for (Entry<String, Coords> key : amap.entrySet()) {
        // /float t = key.getValue().x; // <-----------error here -- java.lang.String cannot be cast
        System.out.println("6" + key.getKey());
        // String xz = key.getValue();
    }

}

public class Coords {
    float x;
    float y;

    public Coords(float x, float y) {
        this.x = x;
        this.y = y;
    }
}

}

Where is `learnGame` declared? What is the type of `learnGame.ass.settings`? — Jesper, Apr 10 '15 at 18:56

score 0 · Accepted Answer · edited May 23 '17 at 11:43

You should be saving/loading from shared preferences like the example given here

//persist
HashMap<String, Integer> counters; //the hashmap you want to save
SharedPreferences pref = getContext().getSharedPreferences("Your_Shared_Prefs", Context.MODE_PRIVATE);
SharedPreferences.Editor editor = pref.edit();    
for (String s : counters.keySet()) {
    editor.putInteger(s, counters.get(s));
}
editor.commit();


//load
SharedPreferences pref = getContext().getSharedPreferences("Your_Shared_Prefs", Context.MODE_PRIVATE);
HashMap<String, Integer> map= (HashMap<String, Integer>) pref.getAll();
for (String s : map.keySet()) {
        Integer value=map.get(s);
        //Use Value
}

You need to look at the return value of the methods you're using in Coords, and use variables typed appropriately to store those return values.

Something like this should work no problem:

 for (Entry<String, Coords> key : amap.entrySet()) {
       float x_value = key.getValue().getX(); 
       float y_value = key.getValue().getY(); 
    }

Should work fine with a getter:

public class Coords {
    float x;
    float y;

    public Coords(float x, float y) {
        this.x = x;
        this.y = y;
    }
     public float getX(){
       return this.x;
      }
     public float getY(){
       return this.y;
      }
}

learnGame.ass.settings.get(); is actually a Map because thats the only thing that settings which is of type preferences will return. My values are still returning as java.lang.String's — blockay, Apr 11 '15 at 01:22
See updated answer, hopefully that example + link will help you better understand saving/loading, I know that one helped me a while back — Petro, Apr 11 '15 at 01:28
yeah that makes sense, sadly im using libgdx http://libgdx.badlogicgames.com/nightlies/docs/api/com/badlogic/gdx/Preferences.html — blockay, Apr 11 '15 at 02:42

score -1 · Answer 2 · edited Apr 10 '15 at 18:50

-1

What you have to do is:

float t = Float.parseFloat(theString);

You should also catch a "NumberFormatException"

edited Apr 10 '15 at 18:50

Jemshit

9,501
5
69
106

answered Apr 10 '15 at 18:07

Ruggero Visintin

1
1

this won't work for me because I need to get 2 floats from "theString" – blockay Apr 11 '15 at 00:11
can you explain what is the type of Coords.x? – Ruggero Visintin Apr 11 '15 at 16:39
its a float, but "theSring" is meant to be of type Coords, which contains x and y..Anyway I asked another question and found out that Libgdx preferences does not accept arrays or collections of objects – blockay Apr 12 '15 at 01:09

score -1 · Answer 3 · answered Apr 10 '15 at 18:31

Your problem at here:

java.util.Map<String, Coords> amap = (java.util.HashMap<String, Coords>) learnGame.ass.settings.get();

You can't just cast Map<String, ?> to HashMap<String, Coords>! It's not TypeSafe!

Try some like this:

Map<String, ?> settings = learnGame.ass.settings.get();
for (Entry<String, ?> entry : settings.entrySet()) {
    if (entry.getValue() instanceof Coords) {
        Coords coords = (Coords) entry.getValue();
        // do some with coords
    }
}

when I tried this, all of my values are still seen as strings. --->entry.getValue() is an instanceof String — blockay, Apr 11 '15 at 00:11

read java.util.Map from a file

3 Answers3