| 1 | /* |
| 2 | * Copyright 2006-2007 the original author or authors. |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | package org.springframework.batch.item.database; |
| 17 | |
| 18 | import java.util.List; |
| 19 | |
| 20 | import org.apache.commons.logging.Log; |
| 21 | import org.apache.commons.logging.LogFactory; |
| 22 | import org.hibernate.SessionFactory; |
| 23 | import org.springframework.batch.item.ItemWriter; |
| 24 | import org.springframework.beans.factory.InitializingBean; |
| 25 | import org.springframework.orm.hibernate3.HibernateOperations; |
| 26 | import org.springframework.orm.hibernate3.HibernateTemplate; |
| 27 | import org.springframework.util.Assert; |
| 28 | |
| 29 | /** |
| 30 | * {@link ItemWriter} that uses a Hibernate session to save or update entities |
| 31 | * that are not part of the current Hibernate session. It will also flush the |
| 32 | * session after writing (i.e. at chunk boundaries if used in a Spring Batch |
| 33 | * TaskletStep). It will also clear the session on write |
| 34 | * default (see {@link #setClearSession(boolean) clearSession} property).<br/> |
| 35 | * <br/> |
| 36 | * |
| 37 | * The writer is thread safe after its properties are set (normal singleton |
| 38 | * behavior), so it can be used to write in multiple concurrent transactions. |
| 39 | * |
| 40 | * @author Dave Syer |
| 41 | * @author Thomas Risberg |
| 42 | * |
| 43 | */ |
| 44 | public class HibernateItemWriter<T> implements ItemWriter<T>, InitializingBean { |
| 45 | |
| 46 | protected static final Log logger = LogFactory |
| 47 | .getLog(HibernateItemWriter.class); |
| 48 | |
| 49 | private HibernateOperations hibernateTemplate; |
| 50 | |
| 51 | private boolean clearSession = true; |
| 52 | |
| 53 | /** |
| 54 | * Flag to indicate that the session should be cleared and flushed at the |
| 55 | * end of the write (default true). |
| 56 | * |
| 57 | * @param clearSession |
| 58 | * the flag value to set |
| 59 | */ |
| 60 | public void setClearSession(boolean clearSession) { |
| 61 | this.clearSession = clearSession; |
| 62 | } |
| 63 | |
| 64 | /** |
| 65 | * Public setter for the {@link HibernateOperations} property. |
| 66 | * |
| 67 | * @param hibernateTemplate |
| 68 | * the hibernateTemplate to set |
| 69 | */ |
| 70 | public void setHibernateTemplate(HibernateOperations hibernateTemplate) { |
| 71 | this.hibernateTemplate = hibernateTemplate; |
| 72 | } |
| 73 | |
| 74 | /** |
| 75 | * Set the Hibernate SessionFactory to be used internally. Will |
| 76 | * automatically create a HibernateTemplate for the given SessionFactory. |
| 77 | * |
| 78 | * @see #setHibernateTemplate |
| 79 | */ |
| 80 | public final void setSessionFactory(SessionFactory sessionFactory) { |
| 81 | this.hibernateTemplate = new HibernateTemplate(sessionFactory); |
| 82 | } |
| 83 | |
| 84 | /** |
| 85 | * Check mandatory properties - there must be a hibernateTemplate. |
| 86 | */ |
| 87 | public void afterPropertiesSet() { |
| 88 | Assert.notNull(hibernateTemplate, |
| 89 | "HibernateItemWriter requires a HibernateOperations"); |
| 90 | } |
| 91 | |
| 92 | /** |
| 93 | * Save or update any entities not in the current hibernate session and then |
| 94 | * flush the hibernate session. |
| 95 | * |
| 96 | * @see org.springframework.batch.item.ItemWriter#write(java.util.List) |
| 97 | */ |
| 98 | public final void write(List<? extends T> items) { |
| 99 | doWrite(hibernateTemplate, items); |
| 100 | hibernateTemplate.flush(); |
| 101 | if (clearSession) { |
| 102 | hibernateTemplate.clear(); |
| 103 | } |
| 104 | } |
| 105 | |
| 106 | /** |
| 107 | * Do perform the actual write operation. This can be overridden in a |
| 108 | * subclass if necessary. |
| 109 | * |
| 110 | * @param hibernateTemplate |
| 111 | * the HibernateTemplate to use for the operation |
| 112 | * @param items |
| 113 | * the list of items to use for the write |
| 114 | */ |
| 115 | protected void doWrite(HibernateOperations hibernateTemplate, |
| 116 | List<? extends T> items) { |
| 117 | |
| 118 | if (logger.isDebugEnabled()) { |
| 119 | logger.debug("Writing to Hibernate with " + items.size() |
| 120 | + " items."); |
| 121 | } |
| 122 | |
| 123 | if (!items.isEmpty()) { |
| 124 | long saveOrUpdateCount = 0; |
| 125 | for (T item : items) { |
| 126 | if (!hibernateTemplate.contains(item)) { |
| 127 | hibernateTemplate.saveOrUpdate(item); |
| 128 | saveOrUpdateCount++; |
| 129 | } |
| 130 | } |
| 131 | if (logger.isDebugEnabled()) { |
| 132 | logger.debug(saveOrUpdateCount + " entities saved/updated."); |
| 133 | logger.debug((items.size() - saveOrUpdateCount) |
| 134 | + " entities found in session."); |
| 135 | } |
| 136 | } |
| 137 | |
| 138 | } |
| 139 | |
| 140 | } |