Accessing array in other class

[ce3c]

Hello,

I'm making my first Java app, and I came across this problem today:
I'd like to access
DB1.database[0] DB2.database[0] DB3.database[0] (etc..) based on an integer i.

{"DB".i}.database[0] doesn't seem to work tho. What is the correct format to do this?

[Fubarable]

You can create a public getter method in the class that holds the array and then have the other class call that public method on an object of the first class (again, the one that holds the array).

By the way, can you clarify this statement here?:

DB1.database[0] DB2.database[0] DB3.database[0] (etc..) based on an integer i.

[BeholdMyGlory]

Hello,

I'm making my first Java app, and I came across this problem today:
I'd like to access
DB1.database[0] DB2.database[0] DB3.database[0] (etc..) based on an integer i.

{"DB".i}.database[0] doesn't seem to work tho. What is the correct format to do this?

You could store the DBs in an array, as such:

DB[] dbArray = new DB[3];
dbArray[0] = new DB();
dbArray[1] = new DB();
dbArray[2] = new DB();
System.out.println(dbArray[2].database[0]);

This is though assuming that you have a class named DB.
Did that make much sense to you?

[Fubarable]

Ah, I think I see now. Behold's explanation seems to be spot on. Please ignore what I posted previously.

[ce3c]

DB[] dbArray = new DB[3];
dbArray[0] = new DB();
dbArray[1] = new DB();
dbArray[2] = new DB();
System.out.println(dbArray[2].database[0]);

I've got 108 class files... putting "dbArray[*] = new DB();" each time doesn't seem the good way to me.

DB1.java
DB2.java
DB3.java
etc...

DB1.java contains this:

class DB1
extends Test
{
	public static String[][] database = {
		{"a", "text sfkejfle kjsekfj sekfj sk"},
		{"b", "fjkjefk esfkje fksejf sjefksekj"}
	};
}

I need to split my classes up over 108 files because Java doesn't allow files over 65535 characters. I'm using (huge) arrays as a database to make some sort of a dictionary in J2ME.

So what I would like to do in fact (in my main Test.java file) is this:

for (int i=1; i<109; i++) {
	helloForm.append({"DB"+i}.database[0][0]);
}

I tried to concat every DB*.database (which doesn't seem possible because of the 65535 char limit).

Sorry, it really is one of my first days Java. I'm used to PHP (that's why I'm writing {"DB"+i} which would be similar..)

[Fubarable]

I've got 108 class files... putting "dbArray[*] = new DB();" each time doesn't seem the good way to me.

Of course you wouldn't do that. You'd use a for loop instead.

Java is very different from PHP and you can't just jump from one type of programming to the other. For instance variable names are not so flexible in Java so what you are trying to do to manipulate them is doomed to fail.

Strong word of advice: stop doing your project now and go through a text book and / or tutorial on Java. If not, you are going to be writing a monstrously large program that you will just have to discard later as it will be impossible to maintain or debug.

[BeholdMyGlory]

DB[] dbArray = new DB[3];
dbArray[0] = new DB();
dbArray[1] = new DB();
dbArray[2] = new DB();
System.out.println(dbArray[2].database[0]);

I've got 108 class files... putting "dbArray[*] = new DB();" each time doesn't seem the good way to me.

DB1.java
DB2.java
DB3.java
etc...

DB1.java contains this:

class DB1
extends Test
{
	public static String[][] database = {
		{"a", "text sfkejfle kjsekfj sekfj sk"},
		{"b", "fjkjefk esfkje fksejf sjefksekj"}
	};
}

I need to split my classes up over 108 files because Java doesn't allow files over 65535 characters. I'm using (huge) arrays as a database to make some sort of a dictionary in J2ME.

So what I would like to do in fact (in my main Test.java file) is this:

for (int i=1; i<109; i++) {
	helloForm.append({"DB"+i}.database[0][0]);
}

I tried to concat every DB*.database (which doesn't seem possible because of the 65535 char limit).

Sorry, it really is one of my first days Java. I'm used to PHP (that's why I'm writing {"DB"+i} which would be similar..)

Wow. That seems impractical. Wouldn't it be possible to have one single class, called "DB", which takes a String array like this:

class DB
extends Test
{
	public String[][] database; //note the removal of static

        public DB(String[][] sArr) {
               database = sArr;
        }
}

And then create an object like this:

String[][] db = {
		{"a", "text sfkejfle kjsekfj sekfj sk"},
		{"b", "fjkjefk esfkje fksejf sjefksekj"}
	};
DB object = new DB(db);

String[] tmp = object.database[0];

or something like that. But what you could do is to store all the data as normal text, and then read from the text file in the program itself. Perhaps creating an array of DB objects based on what's in the text file.

[ce3c]

Perhaps creating an array of DB objects based on what's in the text file.

At the moment it is a J2ME program, I'm building it for my mobile phone. Accessing its filesystem is way more complicated, and the data wouldn't be compressed like in the .JAR which the compiler produces.

Isn't there a function like StringToClassName() ?

I'll try to put everything into a different entry of an array, but I'm afraid the 65535 charlimit-error will rise again.

[ce3c]

Bumping up this old thread..
been away a while but found a solution to my problem now.
For other noobies who have the same problem:

I didn't know the class name I wanted to load before the app was executed.
The solution was (quite) simple though:

If you would like to "DB1.class" or "DB2.class" depending on an int,
this is the way:

try {
	Class.forName("DB1").newInstance(); 
	// or Class.forName("DB"+int).newInstance();   where int=1;
	// equals "new DB1();"
} catch (InstantiationException e) {
	e.printStackTrace();
} catch (IllegalAccessException e) {
	e.printStackTrace();
} catch (ClassNotFoundException e) {
	e.printStackTrace();
}