1. Jsp -> Only presentation logic
2. Servlets -> Business logic
3. jdbc queries -> Properties files
4. use variables as meaningful names.
5. html field names and servlet fields must be same.
6. Maintain a separate properties file for every module to store jdbc queries
7. Use only prepareStatement(). This line of code should get executed only one time through out the life time of application. So that use static bloxk n write this code. In methods simply write either executeQuery() or executeUpdate() according to requirements after setting all the input values.
8. Write persistence logics (database related logics) only in DAO [Data Access Object] class
9. Exception handling is madatory for every java method
10. Use log4j instead of System.out.println() messages