Reading/Writing To/From a text file

[StonePickaxes]

I am trying to make a save system for my text-based game, and thought it would be a good idea to use a .txt file for saving.

How can I do this?

Thanks.

P.S. If there is a better way than using a .txt file, please let me know.

[gbeebe]

For reading in my applet... Haven't figured out write yet.

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public void readSettings() {       InputStream inStream = null;        BufferedReader bufReader = null;        String ln;                        try {           inStream = getClass().getResourceAsStream("res/settings.txt");           bufReader = new BufferedReader(new InputStreamReader(inStream));            while (null != (ln = bufReader.readLine())) {               //Display the line of text                System.out.println(ln);            }        }catch (Exception e) {           e.printStackTrace();        }finally {           try {               if (bufReader != null) bufReader.close();               if (inStream != null) inStream.close();           }catch (IOException e) {              e.printStackTrace();           }        }          }

[ra4king]

That's because you can't write to a file when running an unsigned applet, but I believe the OP is asking about a console app.

How about using the new features in Java 7?

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public void readSettings() {     try(BufferedReader reader = new BufferedReader(getClass().getResourceAsStream("settings.txt")) {         String line;         while((line = reader.readLine()) != null) {             //deal with the line        }     } }

Also it might be easier to use Scanner, since it offers a bit more useful methods (especially when reading from a settings file):

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public void readSettings() {     Scanner scanner = new Scanner(getClass().getResourceAsStream("settings.txt"));         while(scanner.hasNextLine()) {         //read from the Scanner    }         scanner.close(); }

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[Nate]

I'm spoiled by FileHandle in libgdx...

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FileHandle file = Gdx.files.internal("stuff.txt"); file.writeString("mooooo", true); // true means overwrite, false is append String text = file.readString();

[StonePickaxes]

Ra4king, in the line where your comment says //read from the scanner, how can I take this data that it reads and store it line-by-line to variables? I want line 1 to be something, line 2 to be another, etc and I can't figure out a way to not have them overlap.

[h3ckboy]

variable = scanner.next()

basically it'll go through all the lines and then get all the lines as it goes through.

not 100% on this though, u may wanna test it, cause I just check the javadoc really quick(FYI, that is where you will find the solutions to a lot of your problems )

[Nyhm]

This is quick-and-dirty, but I think it clarifies what StonePickaxes is asking. If you absolutely positively know you have three settings (three lines) in your file:

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class MySettings {     private final String settingA;     private final String settingB;     private final String settingC;     MySettings() {       Scanner scanner = new Scanner(getClass().getResourceAsStream("settings.txt"));           settingA = scanner.nextLine();       settingB = scanner.nextLine();       settingC = scanner.nextLine();           scanner.close();     } }

[Z-Man]

How about using the new features in Java 7?

It's not backwards compatible although the OP is probably not worried about this at the moment. Just be warned, try-with-resources is a Java 7 thing.

[StonePickaxes]

This is quick-and-dirty, but I think it clarifies what StonePickaxes is asking. If you absolutely positively know you have three settings (three lines) in your file:

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class MySettings {     private final String settingA;     private final String settingB;     private final String settingC;     MySettings() {       Scanner scanner = new Scanner(getClass().getResourceAsStream("settings.txt"));           settingA = scanner.nextLine();       settingB = scanner.nextLine();       settingC = scanner.nextLine();           scanner.close();     } }

Ok, so I'm trying to use this, but I keep getting this error on the getClass() -

Cannot make a static reference to the non-static method getClass() from the type Object

Any ideas?

EDIT -

So I figured out why, I need to make the class "public void" and not static, but now when I try to call the method via SaL.Load() it doesn't work.

Thanks for the help.

[philfrei]

in general, to get rid of the "static vs non-static" error, you can make an instance of the class, and call the method off of that instance. That includes making an instance of the class you are within.

In other words:

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MySettings mySettings = new MySettings();   // and later Scanner scanner = new Scanner(mySettings.getClass().getResourceAsStream("settings.txt")); // but for what you are doing, this is the more common form: Scanner scanner = new Scanner(MySettings.class.getResourceAsStream("settings.txt"));

An example of the second form is used in this tutorial.
http://docs.oracle.com/javase/tutorial/uiswing/components/icon.html

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[StonePickaxes]

Ok, but what does the MySettings represent, the file reading from?

[Nyhm]

Sorry, the MyClass example was intended as pseudo-code. I encapsulated your various settings in a class. The class's constructor reads the values from the external file. You should add getter methods to the class to expose the setting values. In your overall program you would construct one, and pass it to any methods that need your settings.

Mainly I wanted to exemplify how to use the Scanner to read a few values, but if you want more discussion of the object model, I can go on and on.

EDIT: I re-read your initial post. Are we even on-topic anymore? Regarding reading/writing to a text file, you should read the java.util.Properties API. It's kind of hacky, but will get the job done for simple name-value pairs. (You'll still have the issue of doing this in an Applet, as ra4king mentioned earlier.)

[philfrei]

Ok, but what does the MySettings represent, the file reading from?

Things seemed to have gotten a bit confused here. I was only addressing the second question about the static vs. non-static error message, and I was using the example code the OP quoted in Post #8. That code is a class definition for the class "MySettings".

If you use "MySettings" (the Name of a class) as the root of a method call, as in "MySettings.class.getResourceAsStream("myFile");"
that is a Static reference, and it tells Java to look in the same directory/location as the compiled class file (as opposed to the Java source file) of the MySettings definition.

Please excuse me if I am undershooting the question. It seems to me that it is possible that the OP wasn't clear on the nature of static vs instance methods and variables, and that this led to his question on post #8.