I’m in the middle of making a platformer game, and I’m wondering what the best way of loading/saving levels and player data would be.
Any suggestions? I mainly just need to know what I am theoretically supposed to do. I’ve never ran into having to read and load files, most of what I’ve done have just been ‘play-through once and see how long it takes till you die’ games, like Mario, for example. ;D
All help is appreciated. 
Hm, ok, to tell you the truth, maybe would be a good idea using Json plus, State Machine Logic.
I made a little drawing for you, took me some time but, i hope it helps 
You can use an XML parser like SAX or DOM to save attributes of a character. At startup, you go through the file and assign the player variables based on the attributes inside the file.
<player>
<attribute name="health" value="100"></attribute>
<attribute name="mana" value="55"></attribute>
<attribute name="xpos" value="102.3"></attribute>
<attribute name="ypos" value="53.0"></attribute>
...
</player>
Thats pretty much how I do it in my game. Also if you are using libgdx there is a very simple method of doing this, but if not this should be helpful: https://github.com/libgdx/libgdx/blob/master/demos/superjumper/superjumper/src/com/badlogicgames/superjumper/Settings.java
Thank you! I will go try that now. Luckily I have basic knowledge of XML, I should have thought of this before ;D
Just an added extra point onto the previous answer.
If you wish to have a more complicated amount of info (for example, saving a players inventory) then the XML format would be difficult. The way you could do it is to make a class called something like “PlayData” and then save it as an object. Like so:
public void saveData(PlayData pd) throws Exception{
//The file it saves to
File filePath ="saves";
if(!filePath.exists()){
//log.info("File path does not exist, creating it...");
filePath.mkdirs();
}//log.info("Got file path, attempting to get file...");
File file = new File("saves/player.data");
if(!file.exists()){
file.createNewFile();
}
FileOutputStream save = new FileOutputStream(file);
// Write object with ObjectOutputStream
ObjectOutputStream saveOut = new ObjectOutputStream (save);
//Now write it out
SaveOut.writeObject (pd);
}
And then to load it:
public PlayerData getPlayerData() throws Exception{
File filePath =new File("saves/player.data");
if(!filePath.exists()){
return null;
}
FileInputStream save = new FileInputStream(filePath);
// Read object using ObjectInputStream
ObjectInputStream saveIn = new ObjectInputStream (save);
// Read an object
Object obj = saveIn.readObject();
if (obj instanceof PlayerData){
return (PlayerData) obj;
}else{
return null;
}
}
So long as everything inside the PlayerData class (including itself) implements Serializable, then this will work.
Hope I helped!
That is a really bad idea, mostly when the game is in a stage of development where classes change rapidly.
The standard serialization is a really bad idea to use for games, since it can break so fast.
Someone told me there’s a work-around for that, so it doesn’t break. Sadly, I forgot who/how.
I recommend either XML,Plain-Text,NBT or JSON.