Re: [RT] Simplifying component handling

[Joerg Heinicke]

On 30.12.2005 19:09, Carsten Ziegeler wrote:

class MyComponent implements SOMETHING, ThreadSafe, Disposable,
Serviceable {
protected ClassA compA;
protected ClassB compB;
protected ServiceManager m;
public void service(ServiceManager m) {
  this.m = m;
  compA = (ClassA)m.lookup(ClassA.ROLE);
  compB = (ClassB)m.lookup(ClassB.ROLE);
}
public void dispose() {
  if ( m != null ) {
    m.release(compA);
    m.release(compB);
  }
}

Way too much code me thinks. So what about:

class MyComponent implements SOMETHING, ThreadSafe {
  protected final ClassA compA;
  protected final ClassB compB;

  public MyComponent(ClassA a, ClassB b) {
    compA = a;
    compB = b;
  }
}

We could simply add constructor injection: if the implementation does
not provide a default constructor, the available constructor is called
using reflection and the components are injected on construction of the
object - no need to configure something in any xml configuration file.
Implementing this is easy - I did this already years ago for Fortress.

What's the contract for the auto-wiring? Just assuming ClassA and ClassB 
have public static fields called ROLE? Sounds somewhat "strange".

Jörg