| /* |
| * 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.samza.application; |
| |
| import org.apache.samza.annotation.InterfaceStability; |
| import org.apache.samza.application.descriptors.ApplicationDescriptor; |
| import org.apache.samza.context.ApplicationContainerContext; |
| import org.apache.samza.context.ApplicationTaskContext; |
| import org.apache.samza.operators.MessageStream; |
| |
| |
| /** |
| * A {@link SamzaApplication} describes the inputs, outputs, state, configuration and the logic for processing data from |
| * one or more streaming sources. |
| * <p> |
| * This is the base {@link SamzaApplication}. Implement a {@link StreamApplication} to describe the processing logic |
| * using Samza's High Level API in terms of {@link MessageStream} operators, or a {@link TaskApplication} to describe it |
| * using Samza's Low Level API in terms of per-message processing logic. |
| * <p> |
| * A {@link SamzaApplication} implementation must have a no-argument constructor, which will be used by the framework to |
| * create new instances and call {@link SamzaApplication#describe(ApplicationDescriptor)}. |
| * <p> |
| * Per container context may be managed using {@link ApplicationContainerContext} and set using |
| * {@link ApplicationDescriptor#withApplicationContainerContextFactory}. Similarly, per task context may be managed |
| * using {@link ApplicationTaskContext} and set using {@link ApplicationDescriptor#withApplicationTaskContextFactory}. |
| */ |
| @InterfaceStability.Evolving |
| public interface SamzaApplication<S extends ApplicationDescriptor> { |
| |
| /** |
| * Describes the inputs, outputs, state, configuration and processing logic using the provided {@code appDescriptor}. |
| * |
| * @param appDescriptor the {@link ApplicationDescriptor} to use for describing the application. |
| */ |
| void describe(S appDescriptor); |
| } |