/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 groovy.sql;
import groovy.lang.
GroovyObjectSupport;
import org.codehaus.groovy.runtime.
DefaultGroovyMethods;
import org.codehaus.groovy.runtime.
InvokerHelper;
import java.sql.
SQLException;
import java.sql.
Statement;
import java.util.
ArrayList;
import java.util.
List;
import java.util.logging.
Logger;
/**
* Class which delegates to a Statement but keeps track of a batch count size.
* If the batch count reaches the predefined number, this Statement does an executeBatch()
* automatically. If batchSize is zero, then no batching is performed.
*/
public class
BatchingStatementWrapper extends
GroovyObjectSupport {
private final
Statement delegate;
protected int
batchSize;
protected int
batchCount;
protected
Logger log;
protected
List<
Integer>
results;
public
BatchingStatementWrapper(
Statement delegate, int
batchSize,
Logger log) {
this.
delegate =
delegate;
this.
batchSize =
batchSize;
this.
log =
log;
reset();
}
protected void
reset() {
batchCount = 0;
results = new
ArrayList<
Integer>();
}
@
Override
public
Object invokeMethod(
String name,
Object args) {
return
InvokerHelper.
invokeMethod(
delegate,
name,
args);
}
public void
addBatch(
String sql) throws
SQLException {
delegate.
addBatch(
sql);
incrementBatchCount();
}
/**
* Increments batch count (after addBatch(..) has been called)
* and execute {@code delegate.executeBatch()} if batchSize has been reached.
*/
protected void
incrementBatchCount() throws
SQLException {
batchCount++;
if (
batchCount ==
batchSize /* never true for batchSize of 0 */) {
int[]
result =
delegate.
executeBatch();
processResult(
result);
batchCount = 0;
}
}
public void
clearBatch() throws
SQLException {
if (
batchSize != 0) {
reset();
}
delegate.
clearBatch();
}
public int[]
executeBatch() throws
SQLException {
if (
shouldCallDelegate()) {
int[]
lastResult =
delegate.
executeBatch();
processResult(
lastResult);
}
int[]
result = new int[
results.
size()];
for (int
i = 0;
i <
results.
size();
i++) {
result[
i] =
results.
get(
i);
}
reset();
return
result;
}
private boolean
shouldCallDelegate() {
if (
batchCount > 0) {
return true;
} else if (
results.
isEmpty()) {
log.
warning("Nothing has been added to batch. This might cause the JDBC driver to throw an exception.");
return true;
}
// Nothing added since last delegate execution. No need to call the delegate this time.
return false;
}
protected void
processResult(int[]
lastResult) {
boolean
foundError = false;
for (int
i :
lastResult) {
if (
i ==
Statement.
EXECUTE_FAILED)
foundError = true;
results.
add(
i);
}
// A little bit of paranoid checking here? Most drivers will throw BatchUpdateException perhaps?
if (
batchCount !=
lastResult.length) {
log.
warning("Problem executing batch - expected result length of " +
batchCount + " but got " +
lastResult.length);
} else if (
foundError) {
log.
warning("Problem executing batch - at least one result failed in: " +
DefaultGroovyMethods.
toList(
lastResult));
} else {
log.
fine("Successfully executed batch with " +
lastResult.length + " command(s)");
}
}
public void
close() throws
SQLException {
delegate.
close();
}
}