28.10. Deploying custom resources

On startup, Seam scans all JARs containing /seam.properties, /META-INF/components.xml or /META-INF/seam.properties for resources. For example, all classes annotated with @Name are registered on startup as Seam components.

You can also use Seam to handle custom resources — that is, Seam can handle specific annotations. First, provide a list of annotation types to handle in the /META-INF/seam-deployment.properties files, like so:

# A colon-separated list of annotation types to handle 
org.jboss.seam.deployment.annotationTypes=com.acme.Foo:com.acme.Bar

Then, collect all classes annotated with @Foo on application startup:

@Name("fooStartup")
@Scope(APPLICATION)
@Startup
public class FooStartup {

   @In("#{deploymentStrategy.annotatedClasses['com.acme.Foo']}")
   private Set<Class<Object>> fooClasses;
   
   @In("#{hotDeploymentStrategy.annotatedClasses['com.acme.Foo']}")
   private Set<Class<Object>> hotFooClasses;

   @Create
   public void create() {
      for (Class clazz: fooClasses) {
         handleClass(clazz);
      }
      for (Class clazz: hotFooClasses) {
         handleClass(clazz);
      }
   }
   
   public void handleClass(Class clazz) {
       // ...
   }

}

You can also set Seam to handle any resource. For example, if you want to process files with the .foo.xml extension, you can write a custom deployment handler:

public class FooDeploymentHandler implements DeploymentHandler { 
  private static DeploymentMetadata FOO_METADATA = new DeploymentMetadata() {

    public String getFileNameSuffix() {
      return ".foo.xml";
    }
  };
  
  public String getName() { 
    return "fooDeploymentHandler"; 
  } 

  public DeploymentMetadata getMetadata() {
    return FOO_METADATA;
  }
}

This provides us with a list of all files with the .foo.xml suffix.

Next, register the deployment handler with Seam in /META-INF/seam-deployment.properties:

# For standard deployment 
# org.jboss.seam.deployment.deploymentHandlers=
#    com.acme.FooDeploymentHandler
 
# For hot deployment 
# org.jboss.seam.deployment.hotDeploymentHandlers=
#    com.acme.FooDeploymentHandler

You can register multiple deployment handlers with a comma-separated list.

Seam uses deployment handlers internally to install components and namespaces, so the handle() is called too early in Seam bootstrap to be useful. You can access the deployment handler easily during the startup of an application-scoped component:

@Name("fooStartup") 
@Scope(APPLICATION) 
@Startup 
public class FooStartup { 
  @In("#{deploymentStrategy.deploymentHandlers['fooDeploymentHandler']}")
  private FooDeploymentHandler myDeploymentHandler;
  @In("#{hotDeploymentStrategy.deploymentHandlers['fooDeploymentHandler']}")
  private FooDeploymentHandler myHotDeploymentHandler;
  @Create public void create() { 
    for (FileDescriptor fd: myDeploymentHandler.getResources()) {
      handleFooXml(fd);
    } 
    for (FileDescriptor f: myHotDeploymentHandler.getResources()) {
      handleFooXml(fd);
    } 
  }
  
  public void handleFooXml(FileDescriptor fd) {
      // ...
  } 
}