Most programs today use as a backend database server. There were many situations when I had that for applications that work to create some classes for database connections, so we considered that the development would be easier I need to do a set of classes to be reusable and easily to change. In this article will be presented several classes that can be used in any Java application to connect to a database server. For reasons of coding, name classes, methods and objects will be in English. Also, I want to say they are not very good on the explanations, so if there exist not ask questions. Begin with an abstract class to be used in class for other classes. This class must contain specific statements to JDBC's methods: getConnection, freeConnection, closeStatement and realeaseAllConnection. Also, this class will include a member of type Properties and which will contain your login (url, user, password, etc ...) the database server.