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.item.validator;
017
018import org.springframework.batch.item.ItemProcessor;
019import org.springframework.beans.factory.InitializingBean;
020import org.springframework.util.Assert;
021
022/**
023 * Simple implementation of {@link ItemProcessor} that validates input and
024 * returns it without modifications. Should the given {@link Validator} throw a
025 * {@link ValidationException} this processor will re-throw it to indicate the
026 * item should be skipped, unless {@link #setFilter(boolean)} is set to
027 * <code>true</code>, in which case <code>null</code> will be returned to
028 * indicate the item should be filtered.
029 * 
030 * @author Robert Kasanicky
031 */
032public class ValidatingItemProcessor<T> implements ItemProcessor<T, T>, InitializingBean {
033
034        private Validator<? super T> validator;
035
036        private boolean filter = false;
037
038        /**
039         * Default constructor
040         */
041        public ValidatingItemProcessor() {
042        }
043
044        /**
045         * Creates a ValidatingItemProcessor based on the given Validator.
046         *
047         * @param validator the {@link Validator} instance to be used.
048         */
049        public ValidatingItemProcessor(Validator<? super T> validator) {
050                this.validator = validator;
051        }
052
053        /**
054         * Set the validator used to validate each item.
055         * 
056         * @param validator the {@link Validator} instance to be used.
057         */
058        public void setValidator(Validator<? super T> validator) {
059                this.validator = validator;
060        }
061
062        /**
063         * Should the processor filter invalid records instead of skipping them?
064         * 
065         * @param filter if set to {@code true}, items that fail validation are filtered
066         * ({@code null} is returned).  Otherwise, a {@link ValidationException} will be
067         * thrown.
068         */
069        public void setFilter(boolean filter) {
070                this.filter = filter;
071        }
072
073        /**
074         * Validate the item and return it unmodified
075         * 
076         * @return the input item
077         * @throws ValidationException if validation fails
078         */
079    @Override
080        public T process(T item) throws ValidationException {
081                try {
082                        validator.validate(item);
083                }
084                catch (ValidationException e) {
085                        if (filter) {
086                                return null; // filter the item
087                        }
088                        else {
089                                throw e; // skip the item
090                        }
091                }
092                return item;
093        }
094
095    @Override
096        public void afterPropertiesSet() throws Exception {
097                Assert.notNull(validator, "Validator must not be null.");
098        }
099
100}