/*
* Copyright 2006-2013 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.batch.item.database;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import javax.sql.DataSource;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.batch.item.ItemWriter;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.dao.DataAccessException;
import org.springframework.dao.EmptyResultDataAccessException;
import org.springframework.dao.InvalidDataAccessApiUsageException;
import org.springframework.jdbc.core.PreparedStatementCallback;
import org.springframework.jdbc.core.namedparam.NamedParameterJdbcOperations;
import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate;
import org.springframework.jdbc.core.namedparam.SqlParameterSource;
import org.springframework.util.Assert;
/**
* <p>{@link ItemWriter} that uses the batching features from
* {@link NamedParameterJdbcTemplate} to execute a batch of statements for all items
* provided.</p>
*
* The user must provide an SQL query and a special callback in the for of either
* {@link ItemPreparedStatementSetter} or {@link ItemSqlParameterSourceProvider}.
* You can use either named parameters or the traditional '?' placeholders. If you use the
* named parameter support then you should provide a {@link ItemSqlParameterSourceProvider},
* otherwise you should provide a {@link ItemPreparedStatementSetter}.
* This callback would be responsible for mapping the item to the parameters needed to
* execute the SQL statement.<br>
*
* It is expected that {@link #write(List)} is called inside a transaction.<br>
*
* The writer is thread-safe after its properties are set (normal singleton
* behavior), so it can be used to write in multiple concurrent transactions.
*
* @author Dave Syer
* @author Thomas Risberg
* @author Michael Minella
* @since 2.0
*/
public class JdbcBatchItemWriter<T> implements ItemWriter<T>, InitializingBean {
protected static final Log logger = LogFactory.getLog(JdbcBatchItemWriter.class);
private NamedParameterJdbcOperations namedParameterJdbcTemplate;
private ItemPreparedStatementSetter<T> itemPreparedStatementSetter;
private ItemSqlParameterSourceProvider<T> itemSqlParameterSourceProvider;
private String sql;
private boolean assertUpdates = true;
private int parameterCount;
private boolean usingNamedParameters;
/**
* Public setter for the flag that determines whether an assertion is made
* that all items cause at least one row to be updated.
* @param assertUpdates the flag to set. Defaults to true;
*/
public void setAssertUpdates(boolean assertUpdates) {
this.assertUpdates = assertUpdates;
}
/**
* Public setter for the query string to execute on write. The parameters
* should correspond to those known to the
* {@link ItemPreparedStatementSetter}.
* @param sql the query to set
*/
public void setSql(String sql) {
this.sql = sql;
}
/**
* Public setter for the {@link ItemPreparedStatementSetter}.
* @param preparedStatementSetter the {@link ItemPreparedStatementSetter} to
* set. This is required when using traditional '?' placeholders for the SQL statement.
*/
public void setItemPreparedStatementSetter(ItemPreparedStatementSetter<T> preparedStatementSetter) {
this.itemPreparedStatementSetter = preparedStatementSetter;
}
/**
* Public setter for the {@link ItemSqlParameterSourceProvider}.
* @param itemSqlParameterSourceProvider the {@link ItemSqlParameterSourceProvider} to
* set. This is required when using named parameters for the SQL statement and the type
* to be written does not implement {@link Map}.
*/
public void setItemSqlParameterSourceProvider(ItemSqlParameterSourceProvider<T> itemSqlParameterSourceProvider) {
this.itemSqlParameterSourceProvider = itemSqlParameterSourceProvider;
}
/**
* Public setter for the data source for injection purposes.
*
* @param dataSource {@link javax.sql.DataSource} to use for querying against
*/
public void setDataSource(DataSource dataSource) {
if (namedParameterJdbcTemplate == null) {
this.namedParameterJdbcTemplate = new NamedParameterJdbcTemplate(dataSource);
}
}
/**
* Public setter for the {@link NamedParameterJdbcOperations}.
* @param namedParameterJdbcTemplate the {@link NamedParameterJdbcOperations} to set
*/
public void setJdbcTemplate(NamedParameterJdbcOperations namedParameterJdbcTemplate) {
this.namedParameterJdbcTemplate = namedParameterJdbcTemplate;
}
/**
* Check mandatory properties - there must be a SimpleJdbcTemplate and an SQL statement plus a
* parameter source.
*/
@Override
public void afterPropertiesSet() {
Assert.notNull(namedParameterJdbcTemplate, "A DataSource or a NamedParameterJdbcTemplate is required.");
Assert.notNull(sql, "An SQL statement is required.");
List<String> namedParameters = new ArrayList<>();
parameterCount = JdbcParameterUtils.countParameterPlaceholders(sql, namedParameters);
if (namedParameters.size() > 0) {
if (parameterCount != namedParameters.size()) {
throw new InvalidDataAccessApiUsageException("You can't use both named parameters and classic \"?\" placeholders: " + sql);
}
usingNamedParameters = true;
}
if (!usingNamedParameters) {
Assert.notNull(itemPreparedStatementSetter, "Using SQL statement with '?' placeholders requires an ItemPreparedStatementSetter");
}
}
/* (non-Javadoc)
* @see org.springframework.batch.item.ItemWriter#write(java.util.List)
*/
@SuppressWarnings({"unchecked", "rawtypes"})
@Override
public void write(final List<? extends T> items) throws Exception {
if (!items.isEmpty()) {
if (logger.isDebugEnabled()) {
logger.debug("Executing batch with " + items.size() + " items.");
}
int[] updateCounts;
if (usingNamedParameters) {
if(items.get(0) instanceof Map && this.itemSqlParameterSourceProvider == null) {
updateCounts = namedParameterJdbcTemplate.batchUpdate(sql, items.toArray(new Map[items.size()]));
} else {
SqlParameterSource[] batchArgs = new SqlParameterSource[items.size()];
int i = 0;
for (T item : items) {
batchArgs[i++] = itemSqlParameterSourceProvider.createSqlParameterSource(item);
}
updateCounts = namedParameterJdbcTemplate.batchUpdate(sql, batchArgs);
}
}
else {
updateCounts = namedParameterJdbcTemplate.getJdbcOperations().execute(sql, new PreparedStatementCallback<int[]>() {
@Override
public int[] doInPreparedStatement(PreparedStatement ps) throws SQLException, DataAccessException {
for (T item : items) {
itemPreparedStatementSetter.setValues(item, ps);
ps.addBatch();
}
return ps.executeBatch();
}
});
}
if (assertUpdates) {
for (int i = 0; i < updateCounts.length; i++) {
int value = updateCounts[i];
if (value == 0) {
throw new EmptyResultDataAccessException("Item " + i + " of " + updateCounts.length
+ " did not update any rows: [" + items.get(i) + "]", 1);
}
}
}
}
}
}