to put data methods inside class or not?

[sde]

i have 2 classes:

customer
product

should i put all my customer functions inside the customer class? or should they be in a seperate database class?

for example, a customer has firstName,lastName ( and a LOT more properties )

should my searchCustomer(), addCustomer(), updateCustomer(), removeCustomer() etc.. be in the customer class? or should i have a seperate database class which manages the data.

there are a lot more classes than just customer and product, so if i make a database class ( as i already have ) it is going to get HUGE, .. but on the other hand, if i put all the customer methods in the customer class, will it be less efficient when i'm creating hundreds or thousands of new customer objects? ( in a search results for example )

maybe there should be a customerData class which just manages the data for the customer?

or would that be going overboard?

[Belisarius]

I don't think it will be less efficient to put more methods in a particular object, but it will be more annoying. Here's how I generally do it (I'm not claiming this is how all Java coders do it, it's just how it works for me).

I create an object to represent a Customer. This has all the properties of the customer, Last Name, First Name . . .

I then create a Util object, CustomerUtil, to interact with the database. Util isn't a standard notation, it's just what I came up with.

Don't create one database operation class, create a database operation package, and put all the "Util" classes in there (or, package them with the objects they're interacting with, it's up to you). You'll create a lot of files, but I think that's better than creating a huge file you need to hunt through for methods.

And generally speaking, my "Util" classes are all static methods, as they generally don't need to keep a state.

[sde]

great, thanks for the insight.