DatabaseService.java
/*
** Module : DatabaseService.java
** Abstract : Helper object for database access.
**
** Copyright (c) 2017-2020, Golden Code Development Corporation.
**
** -#- -I- --Date-- --------------------------------Description----------------------------------
** 001 ECF 20170428 Created first version.
** 002 ECF 20171011 Escape single backslash character in LIKE phrase r-value.
** 003 ECF 20180823 Added MVCC=FALSE to JDBC URL for upgrade to H2 1.4.197.
** 004 AIL 20200906 Dropped MVCC=FALSE and MULTI_THREADED=1 for upgrade to H2 1.4.200.
*/
/*
** This program is free software: you can redistribute it and/or modify
** it under the terms of the GNU Affero General Public License as
** published by the Free Software Foundation, either version 3 of the
** License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
** GNU Affero General Public License for more details.
**
** You may find a copy of the GNU Affero GPL version 3 at the following
** location: https://www.gnu.org/licenses/agpl-3.0.en.html
**
** Additional terms under GNU Affero GPL version 3 section 7:
**
** Under Section 7 of the GNU Affero GPL version 3, the following additional
** terms apply to the works covered under the License. These additional terms
** are non-permissive additional terms allowed under Section 7 of the GNU
** Affero GPL version 3 and may not be removed by you.
**
** 0. Attribution Requirement.
**
** You must preserve all legal notices or author attributions in the covered
** work or Appropriate Legal Notices displayed by works containing the covered
** work. You may not remove from the covered work any author or developer
** credit already included within the covered work.
**
** 1. No License To Use Trademarks.
**
** This license does not grant any license or rights to use the trademarks
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** name Golden Code, FWD, or the names of any author or contributor, for
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** attribution required in this license.
*/
package com.goldencode.p2j.report.server;
import java.sql.*;
import org.h2.jdbcx.*;
import com.goldencode.p2j.cfg.*;
/**
* This class provides database services needed by the report API and maintains a connection
* pool with the database.
*/
class DatabaseService
{
/** Absolute path to the project's home directory */
static final String p2jHomePath;
/** Singleton instance of this class */
private static final DatabaseService singleton;
static
{
try
{
// determine P2J_HOME path
String home = Configuration.home();
char sep = Configuration.P2J_FILE_SEP;
p2jHomePath = home + sep;
singleton = new DatabaseService();
singleton.initialize();
// load database driver
Class.forName("org.h2.Driver");
}
catch (ClassNotFoundException | ConfigurationException exc)
{
throw new RuntimeException(exc);
}
}
/** Connection pool (using default size of 10 and timeout of 30 seconds) */
private final JdbcConnectionPool pool;
/**
* Default constructor. Creates the connection pool and initialize the database for the
* report API's use.
*/
DatabaseService()
{
long maxMemory = Runtime.getRuntime().maxMemory();
long cacheSize = -1;
if (maxMemory < Long.MAX_VALUE)
{
cacheSize = maxMemory / 1024 / 2;
}
String url = "jdbc:h2:"
+ p2jHomePath
+ "rptdb/rptdb;"
+ "DB_CLOSE_DELAY=-1;"
+ "DB_CLOSE_ON_EXIT=FALSE;"
+ "AUTOCOMMIT=OFF;"
+ "DEFAULT_LOCK_TIMEOUT=10000;"
+ "LOCK_MODE=3;"
+ "MV_STORE=FALSE";
if (cacheSize > -1)
{
url += (";CACHE_SIZE=" + cacheSize);
}
// TODO: use real user/pass
pool = JdbcConnectionPool.create(url, "admin", "admin");
}
/**
* Get the singleton instance of this class.
*
* @return Database access services object.
*/
static DatabaseService get()
{
return singleton;
}
/**
* Check out a connection from the connection pool.
*
* @return Shared JDBC connection.
*
* @throws SQLException
* if there is an error retrieving, opening, or preparing the connection.
*/
Connection openConnection()
throws SQLException
{
Connection conn = pool.getConnection();
try (Statement stmt = conn.createStatement())
{
stmt.execute("set autocommit off");
conn.commit();
}
return conn;
}
/**
* Escape all percent and underscore symbols in the text that will be used as the r-value
* of a SQL LIKE expression, since these characters have special meaning to the LIKE
* processing. Backslash ({@code \}) is used as the escape character. Also escape single
* backslash characters.
*
* @param text
* R-value text.
*
* @return String with embedded escape sequences for percent and underscore characters.
*/
String escapeLikeRValue(String text)
{
return text.replaceAll("\\\\", "\\\\\\\\").replaceAll("%", "\\%").replaceAll("_", "\\_");
}
/**
* Initialize database services for all sessions to use. This involves creating a global
* temporary table to represent the selection of files which are active for the sessions'
* report result filtering purposes.
*/
void initialize()
{
try (Connection conn = openConnection())
{
try (Statement stmt = conn.createStatement())
{
// create active_file temp table
String sql =
"create global temporary table active_file (fid bigint, sid bigint, " +
"constraint fk_actfile_fid foreign key(fid) references file(id))";
stmt.execute(sql);
conn.commit();
}
catch (SQLException exc)
{
conn.rollback();
throw new RuntimeException(exc);
}
}
catch (SQLException exc)
{
throw new RuntimeException(exc);
}
}
}