Extending class using fields/variables

[Michael Carroll]

Hi,

I have a generic class that delivers my functionality. I then extend this class and just pass in configuration. However, I would like this configuration to be in the form of fields/variables, as opposed to setter methods. I'm wanting to do similar to the following;

public class a extends b
{
public String val = "abc";
public void processRequest()
{
super.processRequest();
}
}

public class b
{
public void processRequest()
{
System.out.println("doing something with val=" + val);
}
}

But I only seem to be able to get the following to work, using setter methods;

public class a extends b
{
public String getVal() { return "abc"; }
public void processRequest()
{
super.processRequest();
}
}

public abstract class b
{
public abstract String getVal();
public void processRequest()
{
System.out.println("doing something with val=" + getVal());
}
}

Anyone have any thoughts or ideas as to how I can get the first option to work? I'm no expert with java, so if it's not possible/goes against OO principles then that's cool too.

Thanks.

[Ernest Friedman-Hill]

The option that's working for you is definitely better style; but you can get it to work the way you want by declaring the variable in the base class, and setting the value in the subclass:

public class a extends b {
public a() { val = "abc"; }
...
public class b {
protected String val;
public void processRequest() {
System.out.println("doing something with val=" + val);
}

That override of processRequest() in class "a" is totally unnecessary, by the way.

[Campbell Ritchie]

Welcome to the Ranch
Since you are new, I have edited your post and added code tags; you can see how much better it looks

[Michael Carroll]

Great stuff - thanks Ernest.

Cheers.

[David Newton]

Just to reiterate what Ernest said, this isn't particularly robust or safe.

[Shanky Sohar]

really great..........i like it

[Michael Carroll]

Yep, I've taken onboard what you guys said, and am sticking with the setter methods.

Thanks.