org.apache.nifi.annotation.lifecycle.OnEnabled Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.nifi.annotation.lifecycle;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Inherited;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
*
* Marker annotation a
* {@link org.apache.nifi.controller.ControllerService ControllerService} can
* use to indicate a method should be called whenever the service is enabled.
* Any method that has this annotation will be called every time a user enables
* the service. Additionally, each time that NiFi is restarted, if NiFi is
* configured to "auto-resume state" and the service is enabled, the method will
* be invoked.
*
*
*
* Methods using this annotation must take either 0 arguments or a single
* argument of type
* {@link org.apache.nifi.controller.ConfigurationContext ConfigurationContext}.
*
*
*
* If a method with this annotation throws a Throwable, a log message and
* bulletin will be issued for the component. In this event, the service will
* remain in an 'ENABLING' state and will not be usable. All methods with this
* annotation will then be called again after a delay. The service will not be
* made available for use until all methods with this annotation have returned
* without throwing anything.
*
*
*
* Note that this annotation will be ignored if applied to a ReportingTask or
* Processor. For a Controller Service, enabling and disabling are considered
* lifecycle events, as the action makes them usable or unusable by other
* components. However, for a Processor and a Reporting Task, these are not
* lifecycle events but rather a mechanism to allow a component to be excluded
* when starting or stopping a group of components.
*
*
*
*/
@Documented
@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Inherited
public @interface OnEnabled {
}