| 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.support; |
| 17 | |
| 18 | import java.sql.PreparedStatement; |
| 19 | import java.sql.SQLException; |
| 20 | import java.util.List; |
| 21 | |
| 22 | import org.springframework.batch.item.ExecutionContext; |
| 23 | import org.springframework.batch.item.database.DrivingQueryItemReader; |
| 24 | import org.springframework.batch.item.database.ItemPreparedStatementSetter; |
| 25 | import org.springframework.batch.item.database.KeyCollector; |
| 26 | import org.springframework.batch.item.util.ExecutionContextUserSupport; |
| 27 | import org.springframework.jdbc.core.ColumnMapRowMapper; |
| 28 | import org.springframework.jdbc.core.JdbcTemplate; |
| 29 | import org.springframework.jdbc.core.PreparedStatementSetter; |
| 30 | import org.springframework.jdbc.core.RowMapper; |
| 31 | import org.springframework.util.Assert; |
| 32 | import org.springframework.util.ClassUtils; |
| 33 | import org.springframework.util.StringUtils; |
| 34 | |
| 35 | /** |
| 36 | * <p> |
| 37 | * JDBC implementation of the {@link KeyCollector} interface that works for |
| 38 | * composite keys. (i.e. keys represented by multiple columns) A SQL query to be |
| 39 | * used to return the keys and a {@link ItemPreparedStatementSetter} to map each |
| 40 | * row in the result set to an Object must be set in order to work correctly. |
| 41 | * </p> |
| 42 | * |
| 43 | * The implementation is thread-safe as long as the |
| 44 | * {@link #setPreparedStatementSetter(ItemPreparedStatementSetter)} and |
| 45 | * {@link #setKeyMapper(RowMapper)} are thread-safe (true for default values). |
| 46 | * |
| 47 | * @author Lucas Ward |
| 48 | * |
| 49 | * @see DrivingQueryItemReader |
| 50 | * @see ItemPreparedStatementSetter |
| 51 | */ |
| 52 | public class MultipleColumnJdbcKeyCollector extends ExecutionContextUserSupport implements KeyCollector { |
| 53 | |
| 54 | private static final String CURRENT_KEY = "current.key"; |
| 55 | |
| 56 | private JdbcTemplate jdbcTemplate; |
| 57 | |
| 58 | private RowMapper keyMapper = new ColumnMapRowMapper(); |
| 59 | |
| 60 | private ItemPreparedStatementSetter preparedStatementSetter = new ColumnMapItemPreparedStatementSetter(); |
| 61 | |
| 62 | private String sql; |
| 63 | |
| 64 | private String restartSql; |
| 65 | |
| 66 | public MultipleColumnJdbcKeyCollector() { |
| 67 | setName(ClassUtils.getShortName(MultipleColumnJdbcKeyCollector.class)); |
| 68 | } |
| 69 | |
| 70 | /** |
| 71 | * Construct a new ItemReader. |
| 72 | * |
| 73 | * @param jdbcTemplate |
| 74 | * @param sql - SQL statement that returns all keys to process. object. |
| 75 | */ |
| 76 | public MultipleColumnJdbcKeyCollector(JdbcTemplate jdbcTemplate, String sql) { |
| 77 | this(); |
| 78 | Assert.notNull(jdbcTemplate, "The JdbcTemplate must not be null."); |
| 79 | Assert.hasText(sql, "The sql statement must not be null or empty."); |
| 80 | this.jdbcTemplate = jdbcTemplate; |
| 81 | this.sql = sql; |
| 82 | } |
| 83 | |
| 84 | /* |
| 85 | * (non-Javadoc) |
| 86 | * |
| 87 | * @see |
| 88 | * org.springframework.batch.io.sql.scratch.AbstractDrivingQueryItemReader |
| 89 | * #retrieveKeys() |
| 90 | */ |
| 91 | public List retrieveKeys(ExecutionContext executionContext) { |
| 92 | |
| 93 | Assert.state(keyMapper != null, "KeyMapper must not be null."); |
| 94 | Assert.state(StringUtils.hasText(restartSql), "The RestartQuery must not be null or empty" |
| 95 | + " in order to restart."); |
| 96 | |
| 97 | if (executionContext.size() > 0) { |
| 98 | Object key = executionContext.get(getKey(CURRENT_KEY)); |
| 99 | return jdbcTemplate.query(restartSql, new PreparedStatementSetterKeyWrapper(key, preparedStatementSetter), |
| 100 | keyMapper); |
| 101 | } |
| 102 | else { |
| 103 | return jdbcTemplate.query(sql, keyMapper); |
| 104 | } |
| 105 | } |
| 106 | |
| 107 | /* |
| 108 | * (non-Javadoc) |
| 109 | * |
| 110 | * @see |
| 111 | * org.springframework.batch.io.driving.KeyGenerator#getKeyAsExecutionContext |
| 112 | * (java.lang.Object) |
| 113 | */ |
| 114 | public void updateContext(Object key, ExecutionContext executionContext) { |
| 115 | Assert.notNull(key, "The key must not be null"); |
| 116 | Assert.notNull(executionContext, "The ExecutionContext must not be null"); |
| 117 | executionContext.put(getKey(CURRENT_KEY), key); |
| 118 | } |
| 119 | |
| 120 | /** |
| 121 | * Set the query to use to retrieve keys in order to restore the previous |
| 122 | * state for restart. |
| 123 | * |
| 124 | * @param restartQuery |
| 125 | */ |
| 126 | public void setRestartSql(String restartQuery) { |
| 127 | this.restartSql = restartQuery; |
| 128 | } |
| 129 | |
| 130 | /* |
| 131 | * (non-Javadoc) |
| 132 | * |
| 133 | * @see |
| 134 | * org.springframework.beans.factory.InitializingBean#afterPropertiesSet() |
| 135 | */ |
| 136 | public void afterPropertiesSet() throws Exception { |
| 137 | Assert.notNull(jdbcTemplate, "The JdbcTemplate must not be null."); |
| 138 | Assert.hasText(sql, "The DrivingQuery must not be null or empty."); |
| 139 | Assert.notNull(keyMapper, "The key RowMapper must not be null."); |
| 140 | } |
| 141 | |
| 142 | /** |
| 143 | * Set the {@link RowMapper} to be used to map a result set to keys. |
| 144 | * |
| 145 | * @param keyMapper |
| 146 | */ |
| 147 | public void setKeyMapper(RowMapper keyMapper) { |
| 148 | this.keyMapper = keyMapper; |
| 149 | } |
| 150 | |
| 151 | /** |
| 152 | * Set the sql statement used to generate the keys list. |
| 153 | * |
| 154 | * @param sql |
| 155 | */ |
| 156 | public void setSql(String sql) { |
| 157 | this.sql = sql; |
| 158 | } |
| 159 | |
| 160 | public void setJdbcTemplate(JdbcTemplate jdbcTemplate) { |
| 161 | this.jdbcTemplate = jdbcTemplate; |
| 162 | } |
| 163 | |
| 164 | public void setPreparedStatementSetter(ItemPreparedStatementSetter preparedStatementSetter) { |
| 165 | this.preparedStatementSetter = preparedStatementSetter; |
| 166 | } |
| 167 | |
| 168 | private static class PreparedStatementSetterKeyWrapper implements PreparedStatementSetter { |
| 169 | |
| 170 | private Object key; |
| 171 | |
| 172 | private ItemPreparedStatementSetter pss; |
| 173 | |
| 174 | public PreparedStatementSetterKeyWrapper(Object key, ItemPreparedStatementSetter pss) { |
| 175 | this.key = key; |
| 176 | this.pss = pss; |
| 177 | } |
| 178 | |
| 179 | public void setValues(PreparedStatement ps) throws SQLException { |
| 180 | pss.setValues(key, ps); |
| 181 | } |
| 182 | } |
| 183 | } |