| 1 | /* |
| 2 | * Copyright 2006-2009 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 | |
| 17 | package org.springframework.batch.item.database; |
| 18 | |
| 19 | import java.sql.Connection; |
| 20 | import java.sql.PreparedStatement; |
| 21 | import java.sql.ResultSet; |
| 22 | import java.sql.SQLException; |
| 23 | |
| 24 | |
| 25 | import org.springframework.jdbc.core.PreparedStatementSetter; |
| 26 | import org.springframework.jdbc.core.RowMapper; |
| 27 | import org.springframework.jdbc.support.JdbcUtils; |
| 28 | import org.springframework.util.Assert; |
| 29 | import org.springframework.util.ClassUtils; |
| 30 | |
| 31 | /** |
| 32 | * <p> |
| 33 | * Simple item reader implementation that opens a JDBC cursor and continually retrieves the |
| 34 | * next row in the ResultSet. |
| 35 | * </p> |
| 36 | * |
| 37 | * <p> |
| 38 | * The statement used to open the cursor is created with the 'READ_ONLY' option since a non read-only |
| 39 | * cursor may unnecessarily lock tables or rows. It is also opened with 'TYPE_FORWARD_ONLY' option. |
| 40 | * By default the cursor will be opened using a separate connection which means that it will not participate |
| 41 | * in any transactions created as part of the step processing. |
| 42 | * </p> |
| 43 | * |
| 44 | * <p> |
| 45 | * Each call to {@link #read()} will call the provided RowMapper, passing in the |
| 46 | * ResultSet. |
| 47 | * </p> |
| 48 | * |
| 49 | * @author Lucas Ward |
| 50 | * @author Peter Zozom |
| 51 | * @author Robert Kasanicky |
| 52 | * @author Thomas Risberg |
| 53 | */ |
| 54 | public class JdbcCursorItemReader<T> extends AbstractCursorItemReader<T> { |
| 55 | |
| 56 | PreparedStatement preparedStatement; |
| 57 | |
| 58 | PreparedStatementSetter preparedStatementSetter; |
| 59 | |
| 60 | String sql; |
| 61 | |
| 62 | RowMapper rowMapper; |
| 63 | |
| 64 | public JdbcCursorItemReader() { |
| 65 | super(); |
| 66 | setName(ClassUtils.getShortName(JdbcCursorItemReader.class)); |
| 67 | } |
| 68 | |
| 69 | /** |
| 70 | * Set the RowMapper to be used for all calls to read(). |
| 71 | * |
| 72 | * @param rowMapper |
| 73 | */ |
| 74 | public void setRowMapper(RowMapper rowMapper) { |
| 75 | this.rowMapper = rowMapper; |
| 76 | } |
| 77 | |
| 78 | /** |
| 79 | * Set the SQL statement to be used when creating the cursor. This statement |
| 80 | * should be a complete and valid SQL statement, as it will be run directly |
| 81 | * without any modification. |
| 82 | * |
| 83 | * @param sql |
| 84 | */ |
| 85 | public void setSql(String sql) { |
| 86 | this.sql = sql; |
| 87 | } |
| 88 | |
| 89 | /** |
| 90 | * Set the PreparedStatementSetter to use if any parameter values that need |
| 91 | * to be set in the supplied query. |
| 92 | * |
| 93 | * @param preparedStatementSetter |
| 94 | */ |
| 95 | public void setPreparedStatementSetter(PreparedStatementSetter preparedStatementSetter) { |
| 96 | this.preparedStatementSetter = preparedStatementSetter; |
| 97 | } |
| 98 | |
| 99 | /** |
| 100 | * Assert that mandatory properties are set. |
| 101 | * |
| 102 | * @throws IllegalArgumentException if either data source or sql properties |
| 103 | * not set. |
| 104 | */ |
| 105 | public void afterPropertiesSet() throws Exception { |
| 106 | super.afterPropertiesSet(); |
| 107 | Assert.notNull(sql, "The SQL query must be provided"); |
| 108 | Assert.notNull(rowMapper, "RowMapper must be provided"); |
| 109 | } |
| 110 | |
| 111 | |
| 112 | protected void openCursor(Connection con) { |
| 113 | try { |
| 114 | if (isUseSharedExtendedConnection()) { |
| 115 | preparedStatement = con.prepareStatement(sql, ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY, |
| 116 | ResultSet.HOLD_CURSORS_OVER_COMMIT); |
| 117 | } |
| 118 | else { |
| 119 | preparedStatement = con.prepareStatement(sql, ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY); |
| 120 | } |
| 121 | applyStatementSettings(preparedStatement); |
| 122 | if (this.preparedStatementSetter != null) { |
| 123 | preparedStatementSetter.setValues(preparedStatement); |
| 124 | } |
| 125 | this.rs = preparedStatement.executeQuery(); |
| 126 | handleWarnings(preparedStatement); |
| 127 | } |
| 128 | catch (SQLException se) { |
| 129 | close(); |
| 130 | throw getExceptionTranslator().translate("Executing query", getSql(), se); |
| 131 | } |
| 132 | |
| 133 | } |
| 134 | |
| 135 | |
| 136 | @SuppressWarnings("unchecked") |
| 137 | protected T readCursor(ResultSet rs, int currentRow) throws SQLException { |
| 138 | return (T) rowMapper.mapRow(rs, currentRow); |
| 139 | } |
| 140 | |
| 141 | /** |
| 142 | * Close the cursor and database connection. |
| 143 | */ |
| 144 | protected void cleanupOnClose() throws Exception { |
| 145 | JdbcUtils.closeStatement(this.preparedStatement); |
| 146 | } |
| 147 | |
| 148 | @Override |
| 149 | public String getSql() { |
| 150 | return this.sql; |
| 151 | } |
| 152 | } |