static public void statistic2(){
		Statement stmt = null;
		ResultSet rs = null;
		
		

		for(int hour = 0; hour < 24; hour ++)
		try {
			String time = "2011-10-07";
			
			String hourTxt = hour + "";
			if(hour < 10){
				hourTxt = "0" + hour;
			}
			
			System.out.print(hour + "\t");
			
			String sqlTxt = "select count(*) as cnt from tweet_2011_10 where published_time_GMT >= \'" + time + " " + hourTxt + ":00:00\'" + 
					" and published_time_GMT <= \'" + time + " " + hourTxt + ":59:59\'";
			
			stmt = conn.createStatement();

			sqlTxt += " and content like \'%jobs%\'";
			
			if (stmt.execute(sqlTxt)) {
				rs = stmt.getResultSet();
				while (rs.next()) {
					int cnt = rs.getInt("cnt");
					System.out.println(cnt);
				}
			}
			

		} catch (SQLException ex) {
			// handle any errors
			System.out.println("SQLException: " + ex.getMessage());
			System.out.println("SQLState: " + ex.getSQLState());
			System.out.println("VendorError: " + ex.getErrorCode());

		} finally {
			// it is a good idea to release
			// resources in a finally{} block
			// in reverse-order of their creation
			// if they are no-longer needed
			if (rs != null) {
				try {
					rs.close();
				} catch (SQLException sqlEx) {
				} // ignore
				rs = null;
			}
			if (stmt != null) {
				try {
					stmt.close();
				} catch (SQLException sqlEx) {
				} // ignore
				stmt = null;
			}
		}
	}