Layer-3 extension layer-7, layer-3 layer-7

Layer-3 extension layer-7, layer-3 layer-7

In the process of data center cooperation, the idea of three layers (UI--BLL--DAL) is used to expand to seven layers, and SVN is used for cooperative development.

During development, data transmission and method calling are all important and frequent. Because of the frequency, chaos is inevitable without planning and management, and it also results in a huge workload of maintenance in the future, just like forming a malignant tumor. From Layer 3 to Layer 7, it is through the layout of the form, as much as possible to avoid the growth of this malignant tumor. Use the form to manage the logic. As we are all discussing, we should avoid corruption in terms of system.

Layer 3. Divides programs into display layer (UI Layer), business logic layer (BLL layer), and data access layer (DAL Layer ).

From three layers to three layers, It is a qualitative overflight.

Multi-person development, the most important thing is that the information is symmetric and the interfaces are consistent. The business needs are sent by the user through the interface, and the business logic is received and analyzed by the appearance hand, you may need to circulate the [interface] to fetch data from the [database] with the help of the [Data Access] Hand.

From Layer 3 to Layer 7, it can only be regarded as quantitative accumulation and form optimization.

After seven layers of division, coupled with the use of the design model, it is like a sentence "writing code is not only a technology, but also an art ".