Software Architecture Design Patterns in Java

8 IMMUTABLE OBJECT

This pattern was previously described in Grand98.

DESCRIPTION

In general, classes in an application are designed to carry data and have behavior. Sometimes a class may be designed in such a way that its instances can be used just as carriers of related data without any specific behavior. Such classes can be called data model classes and instances of such classes ar e referred to as data objects. For example, consider the Employee class in Figure 8.1 and Listing 8.1.

Employee

firstName:String

lastName:String

SSN:String

address:String

car:Car

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getFirstName():String

getLastName():String

getSSN():String

getAddress():String

getCar():Car

setFirstName(fname:String)