import java.sql.*;
public class DB {
	private String driver = "com.mysql.jdbc.Driver";
	private String host = "jdbc:mysql://localhost";
	private String dbName = "test";
	private int port = 3306;
	private String userDB = "root";
	private String passDB = "macarong";
	private Statement sta;
	
	public DB() {
		super();
	}
	
	public void connect() throws Exception {
		Class.forName(driver);
		String url = host + ":" + port + "/" + dbName;
		Connection con = DriverManager.getConnection(url,userDB,passDB);
		sta = con.createStatement();
	}
	
	public ResultSet execSQL(String query) throws Exception {
		ResultSet res = sta.executeQuery(query);
		return res != null ? res : null;
	}
	
	public int updateSQL(String sql) throws Exception {
		int i = sta.executeUpdate(sql);
		return i > 0 ? i : 0;
	}
}

import java.sql.*;
public class mystack {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		DB db = new DB();
		try {
			db.connect();
			ResultSet rs = db.execSQL("select * from User");
			while(rs.next()) {
				System.out.print(rs.getString("Username") + "\t" + rs.getString("Email"));
			}
		} catch (Exception e) {
			System.out.print("Loi he thong:" + e);
		}
	}

}

Object *getObject(){
         Object *obj = new Object();
         return obj;
}

Object *getObject(){
         Object obj;
         return &obj;
}