001/*
002 * Copyright 2006-2007 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016package org.springframework.batch.core.job.flow;
017
018import java.util.Collection;
019
020/**
021 * @author Dave Syer
022 * @since 2.0
023 */
024public interface Flow {
025
026        /**
027         * @return the name of the flow
028         */
029        String getName();
030
031        /**
032         * Retrieve the State with the given name. If there is no State with the
033         * given name, then return null.
034         * 
035         * @param stateName the name of the state to retrieve
036         * @return the State
037         */
038        State getState(String stateName);
039
040        /**
041         * @param executor the {@link FlowExecutor} instance to use for the flow execution.
042         * @return a {@link FlowExecution} containing the exit status of the flow.
043         *
044         * @throws FlowExecutionException thrown if error occurs during flow execution.
045         */
046        FlowExecution start(FlowExecutor executor) throws FlowExecutionException;
047
048        /**
049         * @param stateName the name of the state to resume on.
050         * @param executor the context to be passed into each state executed.
051         * @return a {@link FlowExecution} containing the exit status of the flow.
052         *
053         * @throws FlowExecutionException thrown if error occurs during flow execution.
054         */
055        FlowExecution resume(String stateName, FlowExecutor executor) throws FlowExecutionException;
056
057        /**
058         * Convenient accessor for clients needing to explore the states of this
059         * flow.
060         * @return the states
061         */
062        Collection<State> getStates();
063
064}