In This Section
SINCE 3.2
Overview
The platform provides the ability to initialize @Configured annotated fields and methods with configuration values from the XRuntime (alternative to using the XRuntime.getValue() API). Annotated fields and methods are discovered automatically for the main Talon application. Additional classes can be exposed using the @AppConfiguredAccessor annotation.
This article describes the usage of the configuration annotations:
| Annotation Type | |
|---|---|
| @Configured | Used to annotate application fields and setter methods for population with settings from configuration. |
| @AppConfiguredAccessor | Used to expose additional configured applications to the Talon server. |
Configuration Annotation Discovery
@Configured Annotation
The @Configured annotation is used to annotate application fields and methods to allow them to be discovered by a Talon Server. The Talon server will populate these fields and methods with settings given in Talon configuration.
The @Configured annotation supports following elements:
| @Configured Element | Type | |
|---|---|---|
| property | String, required | The configuration property name. |
| required | boolean, optional | Flag indicating whether the property is required or not. Default: false |
| defaultValue | String, optional | The default value of the property. Default: "<null>" |
| description | String, optional | A description of the property. Default: "<null>" |
@AppIntrospectionPoints
Any @Configured annotated field or method in the main application class will be discovered by the Talon XVM. If additional classes in your application contain configured fields or methods, they can be exposed to the server using the @AppIntrospectionPoints annotation or @AppConfiguredAccessor annotation. The AppIntrospectionPoints annotation exposes a collection of application objects to introspect for any type of annotation supported by Talon while the AppConfiguredAccessor exposes a set of objects that should only be introspected for @Configured annotations. One can use the more narrowly scoped AppConfiguredAccessor annotation for applications that have a large number of objects to reduce the number of objects that the XVM needs to scan.
Example:
@AppConfiguredAccessor
Any @Configured annotated field or method in the main application class will be discovered by the Talon server. If additional classes in your application contain configured fields or methods, they can be exposed to the server using the @AppConfiguredAccessor annotation.
Example:
Configuration Discovery in Hornet
For Topic Oriented Applications, any @Managed object will be introspected for @Configured fields and methods. See ManagedObjectLocator. The DefaultManagedObjectLocator for TOA calls TopicOrientedApplication.addConfiguredContainers(Set), so unless your application provides its own managed object locator, additional configured containers can be added by overriding addConfiguredContainers():
Supported Configuration Types
Configuration values can be of the following types:
- boolean
- byte
- short
- int
- long
- float
- double
- char
- String or XString
- enumerations
Fields
When running in a Talon Server, it is possible to annotate @Configured fields:
Setter Methods
When running in a Talon Server, it is possible to annotate @Configured setter methods:
Limitations
In order to avoid potential race conditions with static fields and preserve the semantics of the "final" keyword, the @Configured annotation does not support injecting properties into fields that are declared static or final. In these cases, the framework will throw a CliException at initialization time.
Programmatic Access to Configuration
Configuration settings remain accessible via the XRuntime.getValue() API.