What does the framework of java mean?

The four-level framework 20 10-06- 12 is a collection of classes and interfaces, through which a series of programs are realized in coordination. Spring mvc can be divided into three layers: presentation layer, business layer and physical layer. Framework, also known as the semi-finished product under development, can't provide everything of the whole WEB application, but with the framework, we can concentrate on developing business logic without caring about its technical implementation and some auxiliary business logic. Well-known Structs and Spring are powerful representatives of presentation layer and business layer framework. When interviewing a general company, have you ever participated in the development of J2EE, you will always test whether you have the cognitive power of this framework. A good framework should consider: stability, flexibility (in a certain development field or industry, it is difficult to be absolutely universal at present), easy to maintain (consistent performance, all operations with the same meaning have the same face), easy for novices to get started, and conducive to the rapid development of n projects (knowledge between projects can be accumulated continuously, and common functions can be separated from project-specific functions). Of course, first of all, what is the framework? Literally means a shelf made up of rules and regulations. How to understand this shelf?

1) frame can be understood in this way. To build a house, the beams and columns of the house should be built first, which is the framework of the house. As for the interior of the house, where is the room and where is the living room, it depends on the designer. The same is true of software. Constructing an approximate beam and column of software is the framework of software. A software semi-finished product helps you do some basic work, and you can customize your own application on this basis. Popular frameworks are very flexible and can meet different needs. For example, if you type on the screen and use System.out.println (), wouldn't it be horrible to implement the println method yourself? Therefore, a framework is needed to solve large-scale problems. 2) The frame is a pine tree. You just need to hang some decorations, some small snowflakes and some small electric lights on it, and you can turn it into a dazzling and festive Christmas tree. 3) A photo frame is like a photo frame. Make a good photo frame. Just put the photos in, whatever you want, big or small. The photo frame is the same, you can change it in the photo. If the photo frame is too small to fit in the photo, the photo frame is not ready. So we can expand a little bit here. The complex program of a framework and the number of things to be loaded are very critical. Now there is a personal criticism that the spring framework is too big and limited. If a project is a school, struts is the department responsible for registration and reception at the beginning of school. When students (requests) come, they will find out which department and class you belong to according to your name (request path), take you to the corresponding place (action), and then the corresponding organization (action) will deal with you. His roster is the configuration file (sturts-config. Xml), on which you can configure your name (request path), verify whether you have tuition (viladate), who you want to take to your organization (request), the car number (formbean) where you put your luggage, and so on. Struts configuration in xml is the information that security guards need to verify. See if you have the admission notice of this school. In your sophomore and junior year, you will become a receptionist. You just need to know which students you want to organize (configure struts-config. Xml), how to deal with them (call that service method), it is struts. Spring's IOC is the recruitment work that should be done by the school, handed over to the headhunting company (control inversion) and then handed over to the school for use. The mode focuses more on the interior of the frame, that is, the combined thinking mode of how furniture is placed in the room.