Question

I have a class like this –

class Messages
  {
      ...
      LinkedList<String> inputs;
      LinkedList<String> outputs;
      ...
  }

Normally, I would initialize inputs and outputs in the constructor –

public Messages()
 {
    inputs = new LinkedList<String>();
    outputs = new LinkedList<String>();
 }

However, I want to achieve the same result using spring configuration. So what should I put under the following node?

<bean id="Messages" class="com.somename.Messages">
                                                   <--- what goes here?
</bean>

When the Spring Container creates the “Messages” bean, will it call the constructor also?

Answer 1

Yes, it will call the constructor. It would be very odd for an IoC container not to call a constructor – it would have to go to some lengths to construct an instance of the object without going through a constructor, and it would almost always be a bad idea.

Of course, you can also initialize your variables as part of the declaration:

class Messages
{
    ...
    private final LinkedList<String> inputs = new LinkedList<String>();
    private final LinkedList<String> outputs = new LinkedList<String>();
    ...
}