Using annotation (recommended but optional)

To register a bean using annotation you need to annotate it with @Bean annotation and pass values for following properties:

  • name - name under which item should be registered
  • active - true if bean should be enabled without enabling it in the configuration (however it is still possible to disable it using configuration)
  • parent - class of the parent bean which activation should trigger registration of your bean. In most cases parent class should be implementing RegistrarBean
  • parents - array of classes which should be threaten as parent classes if more than one parent class is required (optional)
  • exportable - true if bean should be visible in all descendant kernels (in other case default visibility rules will be applied) (optional)
  • selectors - array of selector classes which will decide whether class should be registered or not (optional)


If parent is set to Kernel.class it tells kernel to register this bean in the root/main kernel (top-level kernel).

If you want your bean SomeDependencyBean to be registered when another bean ParentBean is being registered (like a required dependency), you may annotate your bean SomeDependencyBean with @Bean annotation like this example:

@Bean(name = "nameOfSomeDependencyBean", parent = ParentBean.class, active = true)
public class SomeDependencyBean {


Works only if bean registered as defaultBeanConfigurator supports this feature. By default Tigase XMPP Server uses DSLBeanConfigurator which is subclass of AbstractBeanConfigurator which provides support for this feature.

Setting parent to class not implementing RegistrarBean interface

If parent is set to the class which is not implementing RegistrarBean interface, then your bean will be registered in the same kernel scope in which parent bean is registered. If you do so, ie. by setting parent to the class of the bean which is registered in the kernel1 and your bean will be also registered in kernel1. As the result it will be exposed to other beans in the same kernel scope. This also means that if you will configure it in the same way as you would set parent to the parent of annotation of the class to which your parent point to.


@Bean(name="bean1", parent=Kernel.class)
public class Bean1 {
    private int field1 = 0;

@Bean(name="bean2", parent=Bean1.class)
public class Bean2 {
    private int field2 = 0;

In this case it means that bean1 is registered in the root/main kernel instance. At the same time, bean2 is also registered to the root/main kernel as its value of parent property of annotation points to class not implementing RegistrarBean.

To configure value of field1 in instance of bean1 and field2 in instance of bean2 in DSL (for more information about DSL format please check section DSL file format of the Admin Guide) you would need to use following entry in the config file:

bean1 {
    field1 = 1
bean2 {
    field2 = 2

As you can see, this resulted in the bean2 configuration being on the same level as bean1 configuration.