How to store and load in java using mapping

Question

I am doing my project in java, my project consists of producing a card game.
I my game at the end of each round the computer will ask the player if he/she wants to save the game. I have looked at some methods on how to do this. It seams that I need a type of mapping but how.
I want to take a String (which is entered by the player) and to this String I want to store various peices of data that can be loaded up later.
The data that I want to store are has follows
1. Name of the player - String
2. Name of the computer- String
3. Points of computer sofar- Int
4. Points of player sofar - Int
5. Target points- Int
If there is a better way then please tell me. thankyou

Answer 1

The format of the saved game could be anything. An easy way to do this is by using the MessageFormat class.
Let's say you use the tab character as a delimiter, and you want to write two strings and 3 ints:
MessageFormat mf = new MessageFormat("{0}\t{1}\t{2,number}\t{3,number}\t{4,number}";
Object[] o = new Object[5];
o[0] = playerName;
o[1] = computerName;
o[2] = new Integer(computerPoints);
o[3] = new Integer(playerPoints);
o[4] = new Integer(targetPoints);
String formatted = mf.format(o);
PrintWriter out = new PrintWriter(new FileWriter("save.txt"));
out.println(formatted);
out.close();
// reading:
BufferedReader in = new BufferedReader(new FileReader("save.txt"));
String s = in.readLine();
Object[] values = mf.parse(s);
playerName = (String)values[0];
computerName = (String)values[1];
computerScore = ((Number)values[2]).intValue();
playerScore = ((Number)values[3]).intValue();
targetScore = ((Number)values[4]).intValue();You could also just write each value on its own line and not using MessageFormat, but just read the values line by line and convert String to ints when needed.