indextable.java

iiitAccessServer是一个用Java编写的基于规则的企业鉴别系统。它作为一个服务器工作

/*******************************************************************************
 * Copyright (C) 2002, 2003
 * ingenieurbuero fuer innovative informationstechnik (iiit)
 * Dipl.-Ing. Joerg Beckmann, Dortmund, Germany
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * version $Id: IndexTable.java,v 1.13 2003/04/13 20:16:42 joerg Exp $
 ******************************************************************************/

package de.iiit.access.server.util.db.cachedb;

import de.iiit.jdbc.*;

import java.util.*;

/** For every expression or group found in the LDAP database there will be exactly
 * on table in the cache database. The cache tables are numbered consecutively when
 * they are created. The index table holds the relation between the name of the
 * expression or group - represented by its MD5 checksum - and the table containig
 * the data.
 */
public class IndexTable
{
    /** CVS Version Tag */
    private static final String vcid = "$Id: IndexTable.java,v 1.13 2003/04/13 20:16:42 joerg Exp $";

    private static final String indexTable = "indextable";

    private static final String createStmt = 
        "create table " + indexTable + "("         +
            "exprkey      char(33) primary key, "   + 
            "tablename    char(20),"                +
            "creationtime bigint)";
    
    private static final String searchStmt = 
        "select count(*) " + 
            "from " + indexTable + " " + 
            "where exprkey = ?";
    
    private static final String searchStmt2 = 
        "select count(*) " + 
            "from " + indexTable + " " + 
            "where tablename = ?";
    
    private static final String selectStmt = 
        "select exprkey, tablename, "   + 
            "creationtime "             + 
            "from " + indexTable + " "  +
            "where exprkey = ?";
    
    private static final String selectStmt2 = 
        "select tablename "   + 
            "from " + indexTable;
    
    private static final String insertStmt = 
        "insert into " + indexTable + " " + 
            "(exprkey, tablename, creationtime) " + 
            " values (?, ?, ?)";

    private static final String updateStmt = 
        "update " + indexTable + " "    + 
            "set tableName = ?, "       + 
            "creationTime = ? "         +
            "where exprKey = ?";
    
    private static final String deleteStmt = 
        "delete from " + indexTable + " " + 
            "where exprKey = ?";
    
    private String exprKey;
    private String tableName;
    private long   creationTime;
    
    /** Creates a new instance of IndexTable */
    private IndexTable()
    {
    }

    /** Creates a new instance of IndexTable
     * @param exprKey the MD5 sum of the name of the expression or group
     * @param tableName the name of the table
     * @param creationTime the creation time of the cache table in milliseconds since January, 1st 1970.
     */    
    public IndexTable(String exprKey, String tableName, long creationTime)
    {
        this.exprKey = exprKey;
        this.tableName = tableName;
        this.creationTime = creationTime;
    }

    /** Creates a new database table todolist.
     * Returns
     * @param pool The database handle to use
     * @throws JdbcException if a JDBC error occurs
     * @return true if table had to be created, false is table was already there
     */
    public static boolean createIndexTable(JdbcConnectionPool pool) throws JdbcException
    {
        boolean result = false;
        
        JdbcDatabaseMetaData md = pool.getMetaData();
        JdbcResultSet rs = md.getTables(null, null, indexTable, new String[] { "TABLE" });

        if (! rs.next())
        {
            result = true;
            JdbcStatement stmt = pool.createStatement();

            stmt.execute(createStmt);
            
            stmt.close();
        }
        
        rs.close();

        return result;
    }
    
    /** Searches the index for a name of an expression or group
     * @param pool The database handle to use
     * @param expressionName The name to search for
     * @throws JdbcException if a JDBC error occurs
     * @return True if the name was found or false if not.
     */    
    public static boolean searchIndex(JdbcConnectionPool pool, String expressionName) throws JdbcException
    {
        JdbcPreparedStatement search = pool.prepareStatement(searchStmt);            

        search.setString(1, expressionName);
            
        JdbcResultSet rs = search.executeQuery();
                            
        rs.first();
        int count = rs.getInt(1);

        rs.close();
        search.close();

        return (count != 0);
    }

    /** Searches the index for a name of a cache table
     * @param pool The database handle to use
     * @param tablename The name to search for
     * @throws JdbcException if a JDBC error occurs
     * @return True if the name was found or false if not.
     */    
    public static boolean searchIndex2(JdbcConnectionPool pool, String tablename) throws JdbcException
    {
        JdbcPreparedStatement search = pool.prepareStatement(searchStmt2);            

        search.setString(1, tablename);
            
        JdbcResultSet rs = search.executeQuery();
                            
        rs.first();
        int count = rs.getInt(1);

        rs.close();
        search.close();

        return (count != 0);
    }

    /** Reads one record from the index table
     * @param pool The database handle to use
     * @param name The name to search for
     * @throws JdbcException if a JDBC error occurs
     * @return The read record or null if there was no one found.
     */    
    public static IndexTable selectIndex(JdbcConnectionPool pool, String name) throws JdbcException
    {
        IndexTable result = null;

        JdbcPreparedStatement select = pool.prepareStatement(selectStmt);            

        select.setString(1, name);

        JdbcResultSet rs = select.executeQuery();
                            
        if (rs.first())
        {
            result = new IndexTable();
            
            result.setExprKey(rs.getString(1));
            result.setTableName(rs.getString(2));
            result.setCreationTime(rs.getLong(3));
        }

        rs.close();
        select.close();

        return result;
    }

    /** Reads all table names from the index table
     * @param pool The database handle to use
     * @throws JdbcException if a JDBC error occurs
     * @return All table names contained in the index table
     */    
    public static Set selectAllTableNames(JdbcConnectionPool pool) throws JdbcException
    {
        HashSet result = new HashSet();
        
        JdbcPreparedStatement select = pool.prepareStatement(selectStmt2);            

        JdbcResultSet rs = select.executeQuery();
        
        while (rs.next())
        {
            result.add(rs.getString(1));
        }
        
        rs.close();
        select.close();

        return result;
    }
    
    /** Inserts the current object into the index table
     * @param pool The database handle to use
     * @throws JdbcException if a JDBC error occurs
     */    
    public void insertIndex(JdbcConnectionPool pool) throws JdbcException
    {
        JdbcPreparedStatement insert = pool.prepareStatement(insertStmt);
        
        insert.setString(1, exprKey);
        insert.setString(2, tableName);
        insert.setLong  (3, creationTime);

        insert.executeUpdate();

        insert.close();
    }

    /** Writes the content of the current object back to the database
     * @param pool The database handle to use
     * @throws JdbcException if a JDBC error occurs
     */    
    public void updateIndex(JdbcConnectionPool pool) throws JdbcException
    {
        JdbcPreparedStatement update = pool.prepareStatement(updateStmt);

        update.setString(1, tableName);
        update.setLong  (2, creationTime);
        update.setString(3, exprKey);

        update.executeUpdate();

        update.close();
    }

    /** Deletes the current object from the database.
     * @param pool The database handle to use
     * @throws JdbcException if a JDBC error occurs
     */    
    public void deleteIndex(JdbcConnectionPool pool) throws JdbcException
    {
        JdbcPreparedStatement delete = pool.prepareStatement(deleteStmt);
        
        delete.setString(1, exprKey);
        delete.executeUpdate();

        delete.close();
    }

    /** Writes the content of the current object back to the database.
     * If it is new it will be inserted, otherwise the record will be updated.
     * @param pool The database handle to use
     * @throws JdbcException if a JDBC error occurs
     */    
    public void writeIndex(JdbcConnectionPool pool) throws JdbcException
    {
        if (! searchIndex(pool, exprKey))
            insertIndex(pool);
        else
            updateIndex(pool);
    }

    /** Sets the exprkey-field of the current object.
     * @param exprKey the MD5 sum of the name of the expression or group
     */    
    public void setExprKey(String exprKey)
    {
        this.exprKey = exprKey;
    }
    
    /** Sets the tablename-field of the current object.
     * @param tableName the name of the cache table
     */    
    public void setTableName(String tableName)
    {
        this.tableName = tableName;
    }
    
    /** Sets the creationtime-field of the current object
     * @param creationTime the creation time of the cache table in milliseconds since January, 1st 1970.
     */    
    public void setCreationTime(long creationTime)
    {
        this.creationTime = creationTime;
    }
            
    /** Retrieves the exprkey-field of the current object.
     * @return the MD5 sum of the name of the expression or group
     */    
    public String getExprKey()
    {
        return exprKey;
    }
    
    /** Retrieves the tablename-field of the current object.
     * @return the name of the cache table
     */    
    public String getTableName()
    {
        return tableName;
    }
    
    /** Retrieves the creationtime-field of the current object
     * @return the creation time of the cache table in milliseconds since January, 1st 1970.
     */    
    public long getCreationTime()
    {
        return creationTime;
    }
}

/**
 * $Log: IndexTable.java,v $
 * Revision 1.13  2003/04/13 20:16:42  joerg
 * Package structure modified
 *
 * Revision 1.12  2003/01/01 21:04:18  joerg
 * Copyright-Statement aktualisiert
 *
 * Revision 1.11  2002/12/23 11:28:23  joerg
 * no message
 *
 * Revision 1.10  2002/12/21 19:55:04  joerg
 * Nicht mehr benoetigte Methoden entfernt, interne Methoden auf
 * private oder protected geaendert.
 * JavaDoc Kommentare ergaenzt.
 *
 * Revision 1.9  2002/12/19 15:54:33  joerg
 * Paket umbenannt in iiitLdapPlugin
 *
 * Revision 1.8  2002/12/08 16:09:46  joerg
 * Paket-Struktur ueberarbeitet
 *
 * Revision 1.7  2002/11/21 21:49:45  joerg
 * Umstellung auf JdbcConnectionPool
 *
 * Revision 1.6  2002/11/21 09:11:53  joerg
 * Neue Methode selectAllTableNames()
 *
 * Revision 1.5  2002/11/20 20:41:29  joerg
 * Klassen fuer das HAndling der DB-Tabellen in Packages
 * de.iiit.AccessServer.db.* verschoben
 *
 * Revision 1.4  2002/11/20 20:24:12  joerg
 * Reste der Spalte 'inverted' entfernt
 *
 * Revision 1.3  2002/11/20 12:42:07  joerg
 * Spalte 'inverted' entfernt
 *
 * Revision 1.2  2002/11/18 22:09:00  joerg
 * CacheManager ausgelagert als PlugIn
 *
 * Revision 1.1  2002/11/18 10:17:49  joerg
 * Klassen des CacheManagers in eigenes Package verschoben
 *
 * Revision 1.1  2002/11/17 22:03:26  joerg
 * Neue Klassen fuer 2nd-level Cache
 *
 */