source: greenstone3/trunk/src/java/org/greenstone/gsdl3/sql/DatabaseFactory.java@ 16652

package org.greenstone.gsdl3.sql;

/**
 * Returns a sql server according to the user's selection
 *
 */

import org.apache.log4j.*;

import java.util.HashMap;

public class DatabaseFactory{
    private static HashMap serverMap = new HashMap();
    private static Logger logger = Logger.getLogger(org.greenstone.gsdl3.sql.DatabaseFactory.class.getName());


    //upcase the first letter
    public static String properDBName(String name_in){
    String name_out = "";
    name_in = name_in.toLowerCase();
    if (name_in.length() >= 1){
        String firstLetter = name_in.substring(0,1).toUpperCase();
        name_out = firstLetter +  name_in.substring(1);
    }
    return name_out;
    }


    public static final SQLServer getDatabaseServer(String dbname){
    dbname = properDBName(dbname);
    if (serverMap.containsKey(dbname)) return (SQLServer) serverMap.get(dbname);
    String fullName = "org.greenstone.gsdl3.sql." + dbname.toLowerCase()+ "." + dbname +"SQLServer";
    try {
        SQLServer server = (SQLServer)Class.forName(fullName).newInstance();
        serverMap.put(dbname, server);
        return server;
    } catch (Exception e) {
        logger.info("Couldn't load the database server "+ fullName);
    }
    
    return null; 
    }

   public static final SQLStatements getSQLStatements(String sqlstate){
       String fullsqlstate = "org.greenstone.gsdl3.sql." + sqlstate;
    //load SQLStatements class
       try{
       SQLStatements state = (SQLStatements)Class.forName(fullsqlstate).newInstance(); 
       return state;
       }
       catch (Exception e) {
       // if falied use sqlstate as a full path
       try{
           SQLStatements state = (SQLStatements)Class.forName(sqlstate).newInstance(); 
           return state;
       }
       catch (Exception e2) {
           // failed again, give up
           logger.info("Couldn't load the sql statement  "+ sqlstate);
       }
       }
        
       return null; 
   }

    public static final MetadataDBWrapper getMetadataDBWrapper(String dbname, String sqlstate){
    dbname = properDBName(dbname);

    String fullName = "org.greenstone.gsdl3.sql." + dbname.toLowerCase()+ "." + dbname +"DBWrapper";
    try {
        MetadataDBWrapper wrapper = (MetadataDBWrapper)Class.forName(fullName).newInstance();
        if (wrapper != null){
        //load SQLServer class
        SQLServer server = getDatabaseServer(dbname);
        if (server != null){
            wrapper.setSQLServer(server);
        }

        String fullsqlstate = "org.greenstone.gsdl3.sql." + sqlstate;
        //load SQLStatements class
        try{
           SQLStatements state = (SQLStatements)Class.forName(fullsqlstate).newInstance(); 
           if (state != null){
               wrapper.setSQLStatements(state); 
               return wrapper;
           }
        }
        catch (Exception e) {
            // if falied use sqlstate as a full path
            try{
            SQLStatements state = (SQLStatements)Class.forName(sqlstate).newInstance(); 
            if (state != null){
                wrapper.setSQLStatements(state);
                return wrapper;
            }
            }
            catch (Exception e2) {
            // failed again, give up
            logger.info("Couldn't load the sql statement  "+ sqlstate);
            }
        }
        }
    } catch (Exception e) {
        logger.info("Couldn't load the database wrapper "+ fullName);
    }
    
    return null; 

    }

}