Dto.java and others classes - for data transmission from/to view (with EL - Expression Language" ) layer to/from business and persistence layer in J2EE application. Dto extends from HashMap class of Java API for encapsulate any type of information by key type:key_i.key_ij.key_ijk....: Any component in any J2EE functional chain can access to DTO if they know the key key_i.key_ij.key_ijk.... for object access. This project helps to decouple the data, business logic and persistence logic...