org.apache.lucene.store.DirectoryTemplate Maven / Gradle / Ivy
/*
* Copyright 2004-2009 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.apache.lucene.store;
import java.io.IOException;
import java.sql.Connection;
import javax.sql.DataSource;
import org.apache.lucene.store.jdbc.JdbcDirectory;
import org.apache.lucene.store.jdbc.datasource.DataSourceUtils;
/**
* A simple directory template for performing operations that result in actions being performed on the
* directory (like index reader/searcher/writer operation). Helps in having the same code base when working
* with different implementation of Lucene Directory
, or switching between un-managed and managed
* transactions with {@link JdbcDirectory}.
*
* Will work with any type of Directory
implementation. Special actions will be taken if the
* {@link JdbcDirectory} is used, where {@link DataSourceUtils#commitConnectionIfPossible(java.sql.Connection)} will
* be called after the callback method.
*
* @author kimchy
*/
public class DirectoryTemplate {
public static interface DirectoryCallback {
Object doInDirectory(Directory dir) throws IOException;
}
public static abstract class DirectoryCallbackWithoutResult implements DirectoryCallback {
public Object doInDirectory(Directory dir) throws IOException {
doInDirectoryWithoutResult(dir);
return null;
}
protected abstract void doInDirectoryWithoutResult(Directory dir) throws IOException;
}
private DataSource dataSource;
private Directory dir;
public DirectoryTemplate(Directory dir) {
this.dir = dir;
if (dir instanceof JdbcDirectory) {
this.dataSource = ((JdbcDirectory) dir).getDataSource();
}
}
public void execute(DirectoryCallback callback) throws IOException {
if (dataSource == null) {
callback.doInDirectory(dir);
return;
}
Connection conn = DataSourceUtils.getConnection(dataSource);
try {
callback.doInDirectory(dir);
DataSourceUtils.commitConnectionIfPossible(conn);
} catch (IOException e) {
DataSourceUtils.safeRollbackConnectionIfPossible(conn);
throw e;
} finally {
DataSourceUtils.releaseConnection(conn);
}
}
}