001/*
002 * Copyright 2006-2018 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.step.tasklet;
017
018import org.springframework.batch.core.ExitStatus;
019import org.springframework.batch.core.StepContribution;
020import org.springframework.batch.core.scope.context.ChunkContext;
021import org.springframework.batch.item.adapter.AbstractMethodInvokingDelegator;
022import org.springframework.batch.repeat.RepeatStatus;
023
024/**
025 * A {@link Tasklet} that wraps a method in a POJO. By default the return
026 * value is {@link ExitStatus#COMPLETED} unless the delegate POJO itself returns
027 * an {@link ExitStatus}. The POJO method is usually going to have no arguments,
028 * but a static argument or array of arguments can be used by setting the
029 * arguments property.
030 *
031 * @see AbstractMethodInvokingDelegator
032 *
033 * @author Dave Syer
034 * @author Mahmoud Ben Hassine
035 *
036 */
037public class MethodInvokingTaskletAdapter extends AbstractMethodInvokingDelegator<Object> implements Tasklet {
038
039        /**
040         * Delegate execution to the target object and translate the return value to
041         * an {@link ExitStatus} by invoking a method in the delegate POJO. Ignores
042         * the {@link StepContribution} and the attributes.
043         *
044         * @see Tasklet#execute(StepContribution, ChunkContext)
045         */
046        @Override
047        public RepeatStatus execute(StepContribution contribution, ChunkContext chunkContext) throws Exception {
048                if (getArguments() == null) {
049                        setArguments(new Object[]{contribution, chunkContext});
050                }
051                contribution.setExitStatus(mapResult(invokeDelegateMethod()));
052                return RepeatStatus.FINISHED;
053        }
054
055        /**
056         * If the result is an {@link ExitStatus} already just return that,
057         * otherwise return {@link ExitStatus#COMPLETED}.
058         *
059         * @param result the value returned by the delegate method
060         * @return an {@link ExitStatus} consistent with the result
061         */
062        protected ExitStatus mapResult(Object result) {
063                if (result instanceof ExitStatus) {
064                        return (ExitStatus) result;
065                }
066                return ExitStatus.COMPLETED;
067        }
068
069}