A Tour of Scala - an interactive scala tutorial - Classes - continued

30 Classes - continued

Uniform Access

Scala’s getters and setters use the principle of uniform access, e.g. if you change the implentation of a field declared var name to a method def name you will not need to recompile the code
Therefore there can’t be a variable or method (def, val or var, private or public) that has the same name in a class

Java style getters and setters

Scala’s automatic getters and setters are following the unoform access principle, so the getter and setter name is the same as the field it encapsulates,
However if you need to have Java client code accessing your Scala class, it’s as easy as adding a @BeanProperty annotation to instruct the compiler to automatically add a Java bean style getter and setter.
For boolean properties of style isFlag use @BooleanBeanProperty instead

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More on Uniform Access Principle

//A full Java boilerplate style class (not idiomatic Scala!)  
class JPerson() {  
  var _name: String = null  
  def this(_name:String) = {  
    this()  
         this._name = _name  
  }  
  //Scala style getters and setters   
  def name_=(_name:String) = this._name = _name  
  def name = this._name  
    
  //Java style getters and setters    
  def getName() = name  
  def setName(name:String) = this.name = name  
}  

//Which can be generated in 1 line of idiomatic Scala   
import beans._  
class SPerson(@BeanProperty var name:String)  
//Note: @BeanProperty is optional   
//(only if you need Java style getters and setters)  

val jp = new JPerson("Java Style")  
val sp = new SPerson("Scala Style")  

println(jp.name)  
println(sp.name)  

jp.name += " sucks!"  
sp.name += " rocks!"  

println(jp.getName)  
println(sp.getName)

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