genericsqlsource.java

jcrontab是一个定时器开源项目包 目前提供存取文件或数据库, 把执行结果寄发 email, 简单地设置在 Tomcat, Resin, Jetty 及 JBoss 之上, 更是可以取代 cron

	 * entryBean each time.
	 *  @throws CrontabEntryException when it can't parse the line correctly
         *  @throws ClassNotFoundException cause loading the driver can throw an
         *  ClassNotFoundException
         *  @throws SQLException Yep can throw an SQLException too
	 */
					
	public void remove(CrontabEntryBean[] beans) 
	    throws  CrontabEntryException, 
	    ClassNotFoundException, SQLException {

	    Connection conn = null;
	    java.sql.PreparedStatement ps = null;
	    try {
		conn = getConnection();
		ps = conn.prepareStatement(queryRemoving);
		for (int i = 0 ; i < beans.length ; i++) {
                ps.setInt(1 , beans[i].getId());
                ps.executeUpdate();
		}
	    } finally {
		try { ps.close(); } catch (Exception e) {}
		try { conn.close(); } catch (Exception e2) {}
	    }
    	}
    
    /**
	 *  This method saves the CrontabEntryBean the actual problem with this
	 *  method is that doesn't store comments and blank lines from the 
	 *  original file any ideas?
	 *  @param CrontabEntryBean bean this method only lets store an 
	 * entryBean each time.
	 *  @throws CrontabEntryException when it can't parse the line correctly
     *  @throws ClassNotFoundException cause loading the driver can throw an
     *  ClassNotFoundException
     *  @throws SQLException Yep can throw an SQLException too
	 */
	public void store(CrontabEntryBean[] beans) throws  CrontabEntryException, 
                            ClassNotFoundException, SQLException {

	    Connection conn = null;
            java.sql.PreparedStatement ps = null;
	    try {
		conn = getConnection();
		ps = conn.prepareStatement(queryStoring);
		for (int i = 0 ; i < beans.length ; i++) {
		    if (beans[i].getId() == -1) 
                    addId(beans[i], conn);
                    ps.setInt(1, beans[i].getId());
                    ps.setString(2 , beans[i].getSeconds());
                    ps.setString(3 , beans[i].getMinutes());
                    ps.setString(4 , beans[i].getHours());
                    ps.setString(5 , beans[i].getDaysOfMonth());
                    ps.setString(6 , beans[i].getMonths());
                    ps.setString(7 , beans[i].getDaysOfWeek());
                    ps.setString(8 , beans[i].getYear());
                    if ("".equals(beans[i].getMethodName())) { 
                        ps.setString(9 , beans[i].getClassName());
                    } else {
                         String classAndMethod = beans[i].getClassName() +
                         "#" + beans[i].getMethodName();
                         ps.setString(9 , classAndMethod);
                    }

                    String extraInfo[] = beans[i].getExtraInfo();
                    String extraInfob = new String();
                    if (extraInfo.length>0) {
                        for (int z = 0; z< extraInfo.length ; z++) {
                            extraInfob += " "+ extraInfo[z];
                        }
                    }
                    ps.setString(10 , extraInfob);
                    ps.setBoolean(11, beans[i].getBusinessDays());
                    ps.executeUpdate();
		}
	    } finally {
		try { ps.close(); } catch (Exception e) {}
		try { conn.close(); } catch (Exception e2) {}
	    }
	}
	
	/**
	 *  This method saves the CrontabEntryBean the actual problem with this
	 *  method is that doesn't store comments and blank lines from the 
	 *  original file any ideas?
	 *  @param CrontabEntryBean bean this method only lets store an 
	 * entryBean each time.
	 *  @throws CrontabEntryException when it can't parse the line correctly
     *  @throws ClassNotFoundException cause loading the driver can throw an
     *  ClassNotFoundException
     *  @throws SQLException Yep can throw an SQLException too
	 */
	public void store(CrontabEntryBean bean) throws  CrontabEntryException, 
                            ClassNotFoundException, SQLException {
                            CrontabEntryBean[] list = {bean};
                            store(list);
	}
    /**
     * Retrieves a connection to the database.  May use a Connection Pool 
     * DataSource or JDBC driver depending on the properties.
     *
     * @return a <code>Connection</code>
     * @exception SQLException if there is an error retrieving the Connection.
     */
    protected Connection getConnection() throws SQLException {
	Crontab crontab = Crontab.getInstance();
	String dbUser = crontab.getProperty(
			    "org.jcrontab.data.GenericSQLSource.username");
	String dbPwd = crontab.getProperty(
			    "org.jcrontab.data.GenericSQLSource.password");
	String dbUrl = crontab.getProperty(
			    "org.jcrontab.data.GenericSQLSource.url");
	if(dbDriver == null) {
	    dbDriver = loadDatabaseDriver(
		crontab.getProperty("org.jcrontab.data.GenericSQLSource.dbDataSource"));
	}
	if(dbDriver instanceof javax.sql.DataSource) {
        if (dbUser != null && dbPwd != null) {
            return ((javax.sql.DataSource)dbDriver).getConnection(dbUser, dbPwd);
        } else {
            return ((javax.sql.DataSource)dbDriver).getConnection();
	    }
	} else {
	    return DriverManager.getConnection(dbUrl, dbUser, dbPwd);
	}
    }

    /** 
     * Initializes the database engine/data source.  It first tries to load 
     * the given DataSource name.  If that fails it will load the database 
     * driver.  If the driver cannot be loaded it will check the DriverManager 
     * to see if there is a driver loaded that can server the URL.
     *
     * @param srcName is the JDBC DataSource name or null to load the driver.
     * 
     * @exception SQLExcption if there is no valid driver.
     */
    protected Object loadDatabaseDriver(String srcName) throws SQLException {
	String dbDataSource = srcName;
	Crontab crontab = Crontab.getInstance();

	if(dbDataSource == null) {
	    String dbDriver = 
	      crontab.getProperty("org.jcrontab.data.GenericSQLSource.driver");
	    Log.info("Loading dbDriver: " + dbDriver);
	    try {
		return Class.forName(dbDriver).newInstance();
	    } catch (Exception ie) {
		Log.error("Error loading " + dbDriver, ie);
		return DriverManager.getDriver( crontab.getProperty( 
								"org.jcrontab.data.GenericSQLSource.url"));
	    }
	} else {
	    try {
		javax.sql.DataSource dataSource = null;
		Log.info("Loading dataSource: " + dbDataSource);
		Context ctx = null;

		ctx = new InitialContext();
		try {
		    dataSource = 
			(javax.sql.DataSource)ctx.lookup(dbDataSource);
		} catch (NameNotFoundException nnfe) {
		    Log.info(nnfe.getExplanation());
		    Log.info("Checking Tomcat Context");
		    Context tomcatCtx = (Context)ctx.lookup("java:comp/env");
		    dataSource = 
			(javax.sql.DataSource)tomcatCtx.lookup(dbDataSource);
		}
		Log.debug("DataSource loaded. ");
		return dataSource;
	    } catch (Exception e) {
		String msg = e.getMessage();
		if(e instanceof NamingException) 
		    msg = ((NamingException)e).getExplanation();
		Log.debug(msg);
		Log.info(msg + " will try to use dbDriver...");
		return loadDatabaseDriver(null);
	    }
	}
    }
    /** 
     * This method adds the correct id to the Bean. This method is could be 
     * replaced by other methods if you need to do this as protected plz let 
     * me know
     *
     * @param CrontabEntryBean The CrontabEntryBean to add Id
     * @param Connection the conn to access to the data
     * 
     * @exception SQLExcption if smth is wrong
     */
    private void addId(CrontabEntryBean bean, Connection conn) 
                                                throws SQLException {
            java.sql.Statement st = conn.createStatement();
		    java.sql.ResultSet rs = st.executeQuery(nextSequence);
		    if(rs!=null) {
			while(rs.next()) {
                int id = rs.getInt("id");
                bean.setId(id + 1 );
            }
            }
            return;
    }
}