cmssqlmanager.java

cms是开源的框架

/*
 * File   : $Source: /usr/local/cvs/opencms/src/org/opencms/db/generic/CmsSqlManager.java,v $
 * Date   : $Date: 2006/03/27 14:52:54 $
 * Version: $Revision: 1.65 $
 *
 * This library is part of OpenCms -
 * the Open Source Content Mananagement System
 *
 * Copyright (c) 2005 Alkacon Software GmbH (http://www.alkacon.com)
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * For further information about Alkacon Software GmbH, please see the
 * company website: http://www.alkacon.com
 *
 * For further information about OpenCms, please see the
 * project website: http://www.opencms.org
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package org.opencms.db.generic;

import org.opencms.db.CmsDbContext;
import org.opencms.db.CmsDbPool;
import org.opencms.file.CmsDataAccessException;
import org.opencms.file.CmsProject;
import org.opencms.main.CmsLog;
import org.opencms.util.CmsStringUtil;

import java.io.ByteArrayInputStream;
import java.io.Serializable;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Properties;

import org.apache.commons.logging.Log;

/**
 * Generic (ANSI-SQL) implementation of the SQL manager.<p>
 * 
 * @author Thomas Weckert 
 * 
 * @version $Revision: 1.65 $
 * 
 * @since 6.0.0 
 */
public class CmsSqlManager extends org.opencms.db.CmsSqlManager implements Serializable, Cloneable {

    /** A pattern being replaced in SQL queries to generate SQL queries to access online/offline tables. */
    protected static final String QUERY_PROJECT_SEARCH_PATTERN = "_${PROJECT}_";

    /** The log object for this class. */
    private static final Log LOG = CmsLog.getLog(CmsSqlManager.class);

    /** The filename/path of the SQL query properties. */
    private static final String QUERY_PROPERTIES = "org/opencms/db/generic/query.properties";

    /** Serial version UID required for safe serialization. */
    private static final long serialVersionUID = -5994026786008303964L;

    /** A map to cache queries with replaced search patterns. */
    protected Map m_cachedQueries;

    /** The type ID of the driver (vfs, user, project, workflow or backup) from where this SQL manager is referenced. */
    protected int m_driverType;

    /** The pool URL to get connections from the JDBC driver manager, including DBCP's pool URL prefix. */
    protected String m_poolUrl;

    /** A map holding all SQL queries. */
    protected Map m_queries;

    /**
     * Creates a new, empty SQL manager.<p>
     */
    public CmsSqlManager() {

        m_cachedQueries = new HashMap();
        m_queries = new HashMap();
        loadQueryProperties(QUERY_PROPERTIES);
    }

    /**
     * Creates a new instance of a SQL manager.<p>
     * 
     * @param classname the classname of the SQL manager
     * 
     * @return a new instance of the SQL manager
     */
    public static org.opencms.db.generic.CmsSqlManager getInstance(String classname) {

        org.opencms.db.generic.CmsSqlManager sqlManager;

        try {
            Object objectInstance = Class.forName(classname).newInstance();
            sqlManager = (org.opencms.db.generic.CmsSqlManager)objectInstance;
        } catch (Throwable t) {
            LOG.error(Messages.get().getBundle().key(Messages.LOG_SQL_MANAGER_INIT_FAILED_1, classname), t);
            sqlManager = null;
        }

        if (CmsLog.INIT.isInfoEnabled()) {
            CmsLog.INIT.info(Messages.get().getBundle().key(Messages.INIT_DRIVER_SQL_MANAGER_1, classname));
        }

        return sqlManager;

    }

    /**
     * Replaces the project search pattern in SQL queries by the pattern _ONLINE_ or _OFFLINE_ depending on the 
     * specified project ID.<p> 
     * 
     * @param projectId the ID of the current project
     * @param query the SQL query
     * @return String the SQL query with the table key search pattern replaced
     */
    protected static String replaceProjectPattern(int projectId, String query) {

        // make the statement project dependent
        String replacePattern = (projectId == CmsProject.ONLINE_PROJECT_ID || projectId < 0) ? "_ONLINE_" : "_OFFLINE_";
        query = CmsStringUtil.substitute(query, QUERY_PROJECT_SEARCH_PATTERN, replacePattern);

        return query;
    }

    /**
     * Attemts to close the connection, statement and result set after a statement has been executed.<p>
     * 
     * @param dbc the current database context
     * @param con the JDBC connection
     * @param stmnt the statement
     * @param res the result set
     */
    public void closeAll(CmsDbContext dbc, Connection con, Statement stmnt, ResultSet res) {

        // NOTE: we have to close Connections/Statements that way, because a dbcp PoolablePreparedStatement
        // is not a DelegatedStatement; for that reason its not removed from the trace of the connection when it is closed.
        // So, the connection tries to close it again when the connection is closed itself; 
        // as a result there is an error that forces the connection to be destroyed and not pooled

        if (dbc == null) {
            LOG.error(Messages.get().getBundle().key(Messages.LOG_NULL_DB_CONTEXT_0));
        }

        try {
            // first, close the connection and (eventually) implicitly all assigned statements and result sets
            if (con != null && !con.isClosed()) {
                con.close();
            }
        } catch (SQLException e) {
            // intentionally left blank
        } finally {
            con = null;
        }

        try {
            // close the statement and (normally) implicitly all assigned result sets
            if (stmnt != null) {
                stmnt.close();
            }
        } catch (SQLException e) {
            // intentionally left blank
        } finally {
            stmnt = null;
        }

        try {
            // close the result set          
            if (res != null) {
                res.close();
            }
        } catch (SQLException e) {
            // intentionally left blank
        } finally {
            res = null;
        }

    }

    /**
     * Retrieves the value of the designated column in the current row of this ResultSet object as 
     * a byte array in the Java programming language.<p>
     * 
     * The bytes represent the raw values returned by the driver. Overwrite this method if another 
     * database server requires a different handling of byte attributes in tables.
     * 
     * @param res the result set
     * @param attributeName the name of the table attribute
     * @return byte[] the column value; if the value is SQL NULL, the value returned is null 
     * @throws SQLException if a database access error occurs
     */
    public byte[] getBytes(ResultSet res, String attributeName) throws SQLException {

        return res.getBytes(attributeName);
    }

    /**
     * Returns a JDBC connection from the connection pool.<p>
     * 
     * Use this method to get a connection for reading/writing project independent data.<p>
     * 
     * @param dbc the current database context
     * 
     * @return a JDBC connection
     * @throws SQLException if the project id is not supported
     */
    public Connection getConnection(CmsDbContext dbc) throws SQLException {

        return getConnection(dbc, 0);
    }

    /**
     * Returns a JDBC connection from the connection pool specified by the given CmsProject id.<p>
     * 
     * Use this method to get a connection for reading/writing data either in online or offline projects
     * such as files, folders.<p>
     * 
     * @param dbc the current database context
     * @param projectId the id of a project (to distinguish between online / offline tables)
     * 
     * @return a JDBC connection
     * @throws SQLException if a database access error occurs
     */
    public Connection getConnection(CmsDbContext dbc, int projectId) throws SQLException {

        if (dbc == null) {
            LOG.error(Messages.get().getBundle().key(Messages.LOG_NULL_DB_CONTEXT_0));
        }
        return getConnection(projectId);
    }

    /**
     * Returns a PreparedStatement for a JDBC connection specified by the key of a SQL query
     * and the CmsProject.<p>
     * 
     * @param con the JDBC connection
     * @param project the specified CmsProject
     * @param queryKey the key of the SQL query
     * @return PreparedStatement a new PreparedStatement containing the pre-compiled SQL statement 
     * @throws SQLException if a database access error occurs
     */
    public PreparedStatement getPreparedStatement(Connection con, CmsProject project, String queryKey)
    throws SQLException {

        return getPreparedStatement(con, project.getId(), queryKey);
    }

    /**
     * Returns a PreparedStatement for a JDBC connection specified by the key of a SQL query
     * and the project-ID.<p>
     * 
     * @param con the JDBC connection
     * @param projectId the ID of the specified CmsProject
     * @param queryKey the key of the SQL query
     * @return PreparedStatement a new PreparedStatement containing the pre-compiled SQL statement 
     * @throws SQLException if a database access error occurs
     */
    public PreparedStatement getPreparedStatement(Connection con, int projectId, String queryKey) throws SQLException {

        String rawSql = readQuery(projectId, queryKey);
        return getPreparedStatementForSql(con, rawSql);
    }

    /**
     * Returns a PreparedStatement for a JDBC connection specified by the key of a SQL query.<p>
     * 
     * @param con the JDBC connection
     * @param queryKey the key of the SQL query