Confused with Java - need help.

billy-sj

Hi,
I am confused with my java code here. Here are two classes i.e. GameSaver.java and GameCharacter.java
I am experimenting with ObjectOutputStream and ObjectInputStream.

Accordingly, the output when I run GameSaver.java should be
50, Elf, bow, sword, dust
200, Troll, bare hands, big axe
120, Magician, spells, invisibility

But, the output I got when I run the GameSaver.java is:
50, Elf, [Ljava.lang.String;@9304b1
200, Troll, [Ljava.lang.String;@1a758cb
120, Magician, [Ljava.lang.String;@a62fc3

Can anyone explain why? For information, I am running jdk1.5.0 and eclipse IDE version 3.0
The code for both GameSaver.java and GameCharacter.java is listed below:


/*
* Created on 29-Nov-2004
*
* TODO To change the template for this generated file go to
* Window - Preferences - Java - Code Style - Code Templates
*/
package com.billy.Serialize;

import java.io.*;


/**
* @author default
*
* TODO To change the template for this generated type comment go to
* Window - Preferences - Java - Code Style - Code Templates
*/
class GameSaver{

public static void main(String[] args) {
GameCharacter one = new GameCharacter(50, "Elf", new String[] {"bow", "sword", "dust"} );
GameCharacter two = new GameCharacter(200, "Troll", new String[] {"bare hands", "big axe"});
GameCharacter three = new GameCharacter(120, "Magician", new String[] {"spells", "invisibility"});

//do things with the characters that might change their state values
//and then save the characters exactly as they are now

try {
ObjectOutputStream os = new ObjectOutputStream(new FileOutputStream("Game.ser"));
os.writeObject(one);
os.writeObject(two);
os.writeObject(three);
os.close();
}catch (IOException ex) {
ex.printStackTrace();
}

//now read them back in
try {
ObjectInputStream is = new ObjectInputStream(new FileInputStream("Game.ser"));
GameCharacter oneAgain = (GameCharacter) is.readObject();
GameCharacter twoAgain = (GameCharacter) is.readObject();
GameCharacter threeAgain = (GameCharacter) is.readObject();
System.out.println(oneAgain.getPower() +", "+one.getType()+", "+one.getWeapons());
System.out.println(twoAgain.getPower() +", "+two.getType()+", "+two.getWeapons());
System.out.println(threeAgain.getPower() +", "+three.getType()+", "+three.getWeapons());
}catch (Exception ex) {
ex.printStackTrace();
}
}
}








/*
* Created on 29-Nov-2004
*
* TODO To change the template for this generated file go to
* Window - Preferences - Java - Code Style - Code Templates
*/
package com.billy.Serialize;

import java.io.Serializable;

/**
* @author default
*
* TODO To change the template for this generated type comment go to
* Window - Preferences - Java - Code Style - Code Templates
*/
public class GameCharacter implements Serializable{
private int power;
private String type;
private String[] weapons;


public GameCharacter(int p, String t) {
power = p;
type = t;
}

public GameCharacter(int p, String t, String[] w) {
power = p;
type = t;
weapons = w;
}

public void setPower(int p) {
power = p;
}

public void setType(String t) {
type = t;
}

public void setWeapons(String[] w) {
weapons = w;
}

public int getPower() {
return power;
}

public String getType() {
return type;
}

public String[] getWeapons(){
return weapons;
}

}

lightnin

new String[] {"bow", "sword", "dust"}


when you write out a String[] , it will always print out garble like this:

[Ljava.lang.String;@9304b1

you need some sort of toString method for those string arrays, to make it print properly. no joke, something simple, else all you'll get are memory references

public String ArrayToString(String[] arr){
String str = "";
for(int i = 0; i < arr.length; i++){
str.concat(arr).concat(" ");
}
return str;
}


or make getWeapons() look like that instead of returning a String[] it'll return a String of space spearated values.

that's a quick n dirty way. i've been searching for a one-liner but i havent come up with one yet

billy-sj

Cheerz.
This makes things clearer to me now.

billy-sj

cheerz.
this makes things clearer now.