todolist.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: ToDoList.java,v 1.10 2003/04/13 20:16:42 joerg Exp $
 ******************************************************************************/

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

import de.iiit.jdbc.*;

import java.util.*;

/** Implements a wrapper for the database table "todolist"
 * This table holds names of expression or group definition which
 * have changed in the LDAP database and therefore must be updated
 * in the cache database.
 */
public class ToDoList
{
    /** CVS Version Tag */
    private static final String vcid = "$Id: ToDoList.java,v 1.10 2003/04/13 20:16:42 joerg Exp $";
    
    private static final String toDoTable = "todolist";

    private static final String createStmt = 
        "create table " + toDoTable + " ("  + 
            "expression varchar(255), "     + 
            "touchtime  bigint, "           +
            "locked     char(1), "          +
            "index idx1 (expression), "     +
            "index idx2 (touchtime))";
        
    private static final String insertStmt = 
        "insert into " + toDoTable + " "        + 
            "(expression, touchtime, locked) "  + 
            "values (?, ?, ?)";
    
    private static final String searchStmt = 
        "select count(*) "              + 
            "from " + toDoTable + " "   + 
            "where expression = ? and locked = 0";

    private static final String selectStmt = 
        "select expression, touchtime, locked " + 
            "from " + toDoTable + " " + 
            "order by touchtime limit 1";
    
    private static final String updateStmt = 
        "update " + toDoTable + " " + 
            "set locked = ? " + 
            "where expression = ? and touchtime = ?";
    
    private static final String deleteStmt = 
        "delete from " + toDoTable + " " + 
            "where expression = ? and touchtime = ?";

    private String  expression;
    private long    touchTime;
    private boolean locked;

    /** Creates a new instance of ToDoList */
    private ToDoList()
    {
    }

    /** Creates a new instance of ToDoList
     * @param expression The name of the expression or group definition
     * @param touchTime The time when the change was recognized in milliseconds since January, 1st 1970
     * @param locked Before the update of the cache db starts this field will be set to '1'.
     * This flag is used for optimization. If another change of the
     * same expression or group is recognized, it will not be added
     * to the todolist if this flag is still zero.
     */    
    public ToDoList(String expression, long touchTime, boolean locked)
    {
        this.expression = expression;
        this.touchTime  = touchTime;
        this.locked     = locked;
    }

    /** Creates a new database table todolist.
     * @param pool The database handle to use
     * @throws JdbcException if a JDBC error occurs
     * @return true if the table was created, false if it was already there.
     */    
    public static boolean createToDoList(JdbcConnectionPool pool) throws JdbcException
    {
        boolean result = false;

        JdbcDatabaseMetaData md = pool.getMetaData();
        JdbcResultSet rs = md.getTables(null, null, toDoTable, new String[] { "TABLE" });

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

            stmt.execute(createStmt);

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

        return result;
    }
    
    /** Inserts a list of names into the database
     * @param pool The database handle to use
     * @param values The names to insert
     * @throws JdbcException if a JDBC error occurs
     */    
    public static void fillToDoList(JdbcConnectionPool pool, Set values) throws JdbcException
    {
        JdbcPreparedStatement pstmt = pool.prepareStatement(insertStmt);

        Iterator i = values.iterator();
        
        while (i.hasNext())
        {
            pstmt.clearBatch();
            pstmt.clearWarnings();
            pstmt.setString(1, (String) i.next());
            pstmt.setLong(2, System.currentTimeMillis());
            pstmt.setString(3, "0");
            pstmt.executeUpdate();
        }
        
        pstmt.close();
    }

    /** Searches for a name
     * @param pool The database handle to use
     * @param cn the name to search for
     * @throws JdbcException if a JDBC error occurs
     * @return true if such a record was found, false if not.
     */    
    public static boolean searchToDo(JdbcConnectionPool pool, String cn) throws JdbcException
    {
        JdbcPreparedStatement stmt = pool.prepareStatement(searchStmt);

        stmt.setString(1, cn);
        JdbcResultSet rs = stmt.executeQuery();
                            
        rs.first();
        int count = rs.getInt(1);

        rs.close();
        stmt.close();
        
        return (count != 0);
    }

    /** Inserts a the current object into the database
     * @param pool The database handle to use
     * @throws JdbcException if a JDBC error occurs
     */    
    public void insertToDo(JdbcConnectionPool pool) throws JdbcException
    {
        if (! searchToDo(pool, expression))
        {
            JdbcPreparedStatement stmt = pool.prepareStatement(insertStmt);

            stmt.setString(1, expression);
            stmt.setLong  (2, touchTime);
            stmt.setString(3, locked ? "1" : "0");
            
            stmt.executeUpdate();

            stmt.close();
        }
    }

    /** Reads and returns the first record out of the todolist.
     * @param pool The database handle to use
     * @throws JdbcException if a JDBC error occurs
     * @return The read record or null if there is no one to read.
     */    
    public static ToDoList selectToDo(JdbcConnectionPool pool) throws JdbcException
    {
        ToDoList result = null;
        
        JdbcPreparedStatement stmt = pool.prepareStatement(selectStmt);
        
        JdbcResultSet rs = stmt.executeQuery();
                            
        if (rs.first())
        {
            result = new ToDoList();
            
            result.setExpression(rs.getString(1));
            result.setTouchTime (rs.getLong(2));
            result.setLocked    ((rs.getInt(3) == 1));
        }

        rs.close();
        stmt.close();
        
        return result;
    }

    /** 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 updateToDo(JdbcConnectionPool pool) throws JdbcException
    {
        JdbcPreparedStatement update = pool.prepareStatement(updateStmt);

        update.setString(1, locked ? "1" : "0");
        update.setString(2, expression);
        update.setLong  (3, touchTime);

        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 deleteToDo(JdbcConnectionPool pool) throws JdbcException
    {
        JdbcPreparedStatement delete = pool.prepareStatement(deleteStmt);
        
        delete.setString(1, expression);
        delete.setLong  (2, touchTime);
        
        delete.executeUpdate();

        delete.close();
    }

    /** Sets the expression field of the current object
     * @param expression the expression
     */    
    public void setExpression(String expression)
    {
        this.expression = expression;
    }
    
    /** Sets the touchtime field of the current object
     * @param touchTime the time in milliseconds since January, 1st 1970
     */    
    public void setTouchTime(long touchTime)
    {
        this.touchTime  = touchTime;
    }
    
    /** Sets the lock field of the current object
     * @param locked true if the record should be locked, false otherwise
     */    
    public void setLocked(boolean locked)
    {
        this.locked     = locked;
    }
    
    /** Retrieves the expression field of the current object
     * @return the expression
     *
     */    
    public String getExpression()
    {
        return expression;
    }
    
    /** Retrieves the touchtime field of the current object
     * @return the time in milliseconds since January, 1st 1970
     */    
    public long getTouchTime()
    {
        return touchTime;
    }
    
    /** Retrieves the lock field of the current object
     * @return true if the record is locked, false otherwise
     */    
    public boolean getLocked()
    {
        return locked;
    }
}

/**
 * $Log: ToDoList.java,v $
 * Revision 1.10  2003/04/13 20:16:42  joerg
 * Package structure modified
 *
 * Revision 1.9  2003/01/01 21:04:18  joerg
 * Copyright-Statement aktualisiert
 *
 * Revision 1.8  2002/12/23 11:28:23  joerg
 * no message
 *
 * Revision 1.7  2002/12/21 19:55:04  joerg
 * Nicht mehr benoetigte Methoden entfernt, interne Methoden auf
 * private oder protected geaendert.
 * JavaDoc Kommentare ergaenzt.
 *
 * Revision 1.6  2002/12/19 15:54:33  joerg
 * Paket umbenannt in iiitLdapPlugin
 *
 * Revision 1.5  2002/12/08 16:09:46  joerg
 * Paket-Struktur ueberarbeitet
 *
 * Revision 1.4  2002/11/21 21:49:45  joerg
 * Umstellung auf JdbcConnectionPool
 *
 * Revision 1.3  2002/11/20 20:41:29  joerg
 * Klassen fuer das HAndling der DB-Tabellen in Packages
 * de.iiit.AccessServer.db.* verschoben
 *
 * 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 1.2  2002/11/18 10:13:18  joerg
 * CacheManager ist jetzt vollstaendig implementiert
 *
 * Revision 1.1  2002/11/17 22:03:26  joerg
 * Neue Klassen fuer 2nd-level Cache
 *
 */