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.sample.domain.multiline;
017
018import org.springframework.batch.item.file.mapping.FieldSetMapper;
019import org.springframework.batch.item.file.transform.FieldSet;
020import org.springframework.beans.factory.InitializingBean;
021import org.springframework.util.Assert;
022import org.springframework.validation.BindException;
023
024/**
025 * Delegating mapper to convert form a vanilla {@link FieldSetMapper} to one
026 * that returns {@link AggregateItem} instances for consumption by the
027 * {@link AggregateItemReader}.
028 * 
029 * @author Dave Syer
030 * 
031 */
032public class AggregateItemFieldSetMapper<T> implements FieldSetMapper<AggregateItem<T>>, InitializingBean {
033
034        private FieldSetMapper<T> delegate;
035
036        private String end = "END";
037
038        private String begin = "BEGIN";
039
040        /**
041         * Public setter for the delegate.
042         * @param delegate the delegate to set
043         */
044        public void setDelegate(FieldSetMapper<T> delegate) {
045                this.delegate = delegate;
046        }
047
048        /**
049         * Public setter for the end field value. If the {@link FieldSet} input has
050         * a first field with this value that signals the start of an aggregate
051         * record.
052         * 
053         * @param end the end to set
054         */
055        public void setEnd(String end) {
056                this.end = end;
057        }
058
059        /**
060         * Public setter for the begin value. If the {@link FieldSet} input has a
061         * first field with this value that signals the end of an aggregate record.
062         * 
063         * @param begin the begin to set
064         */
065        public void setBegin(String begin) {
066                this.begin = begin;
067        }
068
069        /**
070         * Check mandatory properties (delegate).
071         * @see org.springframework.beans.factory.InitializingBean#afterPropertiesSet()
072         */
073        @Override
074        public void afterPropertiesSet() throws Exception {
075                Assert.notNull(delegate, "A FieldSetMapper delegate must be provided.");
076        }
077
078        /**
079         * Build an {@link AggregateItem} based on matching the first column in the
080         * input {@link FieldSet} to check for begin and end delimiters. If the
081         * current record is neither a begin nor an end marker then it is mapped
082         * using the delegate.
083         * @param fieldSet a {@link FieldSet} to map
084         * 
085         * @return an {@link AggregateItem} that wraps the return value from the
086         * delegate
087         * @throws BindException if one of the delegates does
088         */
089        @Override
090        public AggregateItem<T> mapFieldSet(FieldSet fieldSet) throws BindException {
091
092                if (fieldSet.readString(0).equals(begin)) {
093                        return AggregateItem.getHeader();
094                }
095                if (fieldSet.readString(0).equals(end)) {
096                        return AggregateItem.getFooter();
097                }
098
099                return new AggregateItem<T>(delegate.mapFieldSet(fieldSet));
100
101        }
102
103}