ssdriver.java

這是一個油Java實作的資料庫系統 是個入門的好材料

/* =============================================================
 * SmallSQL : a free Java DBMS library for the Java(tm) platform
 * =============================================================
 *
 * (C) Copyright 2004-2007, by Volker Berlin.
 *
 * Project Info:  http://www.smallsql.de/
 *
 * 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.
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
 * USA.  
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
 * in the United States and other countries.]
 *
 * ---------------
 * SSDriver.java
 * ---------------
 * Author: Volker Berlin
 * 
 */
package smallsql.database;

import java.sql.*;
import java.util.Properties;
import java.util.StringTokenizer;

import smallsql.database.language.Language;

public class SSDriver implements Driver {

	static final String URL_PREFIX = "jdbc:smallsql";
	
	static SSDriver drv;
    static {
        try{
        	drv = new SSDriver();
            java.sql.DriverManager.registerDriver(drv);
//DriverManager.setLogStream(System.out);
//DriverManager.setLogStream(new java.io.PrintStream(new java.io.FileOutputStream("jdbc.log")));
        }catch(Throwable e){
            e.printStackTrace();
        }
	}
    

    public Connection connect(String url, Properties info) throws SQLException{
        if(!acceptsURL(url)){
            return null;
        }
        return new SSConnection(parse(url, info));
    }


    /**
     * Parsed the JDBC URL and build together
     * 
     * @param url
     *            the JDBC URL
     * @param info
     *            a list of arbitrary properties
     * @return a new Properties object
     */
    private Properties parse(String url, Properties info) throws SQLException {
        Properties props = (Properties)info.clone();
        if(!acceptsURL(url)){
            return props;
        }
        int idx1 = url.indexOf(':', 5); // search after "jdbc:"
        int idx2 = url.indexOf('?');
        if(idx1 > 0){
            String dbPath = (idx2 > 0) ? url.substring(idx1 + 1, idx2) : url.substring(idx1 + 1);
            props.setProperty("dbpath", dbPath);
        }
        if(idx2 > 0){
            String propsString = url.substring(idx2 + 1);
            StringTokenizer tok = new StringTokenizer(propsString, ";");
            while(tok.hasMoreTokens()){
                String keyValue = tok.nextToken().trim();
                if(keyValue.length() > 0){
                    idx1 = keyValue.indexOf('=');
                    if(idx1 > 0){
                        String key = keyValue.substring(0, idx1).toLowerCase().trim();
                        String value = keyValue.substring(idx1 + 1).trim();
                        props.put(key, value);
                    }else{
                    	throw SmallSQLException.create(Language.CUSTOM_MESSAGE, "Missing equal in property:" + keyValue);
                    }
                }
            }
        }
        return props;
    }


    public boolean acceptsURL(String url){
        return url.startsWith(URL_PREFIX);
    }


    public DriverPropertyInfo[] getPropertyInfo(String url, Properties info)
    throws SQLException {
        Properties props = parse(url, info);
        DriverPropertyInfo[] driverInfos = new DriverPropertyInfo[1];
        driverInfos[0] = new DriverPropertyInfo("dbpath", props.getProperty("dbpath"));
        return driverInfos;
    }
    
    
    public int getMajorVersion() {
        return 0;
    }
    
    
    public int getMinorVersion() {
        return 19;
    }
    
    
    public boolean jdbcCompliant() {
        return true;
    }
}