parking lot design java

The 14th chapter of the design pattern-command mode (Java implementation)　　"Xiaoming, get the hell out." "Xiaoming, how does this matter?" "(poor xiaoming was helpless to lay a gun.) Xiao Ming: Teacher, I and you have what grudge, I and you have what grudge what resentment ah 、、、 teacher: Xiao Ming, get out. Get used to it. Xiao Ming: 、、、) for this phenomenon, please ask the command mode to do a commentary.

Singleton mode is a common design pattern in the development of projects in peacetime, the use is more common, the information on the Internet is a catch a lot, small Alan also come to join in the fun, for the future to enrich the content of the design pattern related to do a simple opening.A singleton pattern is a pattern of creating objects that produces a spec

First, a primer We go to the technology market for their own machine to add some luxury accessories, a lot of diyer like to find agents, because in the agents there is not only the quality assurance, but also the price and after-sales service will be much better. Customers through the agent to get what they want, but also enjoy the agents of the additional services, and manufacturers through agents to promote their products, and can be some sales se

, there may be a lot of data to be inserted at a certain time, and we can remove some invalid actions by sorting the table, primary key and operation type. For example:A) Multiple update of the same primary key on the same table, whichever is last.b) The same primary key as the same table, all previous actions are invalid whenever a delete occurs.2. Since we want to sort the operations, there is bound to be a time-based sort, how to guarantee the lock

format, TT will verify the validity of the data (usually the type of train is a fixed number of type code, less change).In web development, such request parameter verification is a lot of, usually after the front-end of the parameter check, the back end is still need to re-rigorous verification. Then for such non-business code can be extracted out, do data validation alone, if the verification passed, then continue the next business processing, do n

5. Session Surface Session façade mode adjusts operations between cooperative enterprise objects and synthesizes application functions into a single, simple interface; it reduces the complexity of collaboration between classes and makes it possible for the caller of the class to change without changing the class, which is typically implemented as a session bean. A complex interaction to hide the underlying EJB. The background of this design pattern

Viewer Design Patternnow a lot of buyers are watching the price change of the house, every time the house price changes, all the buyers can be observed. In fact, the above buyers are the observers, they are concerned about the price of the house. if you want to implement the observer pattern, you must rely on the observable class and observer interfaces provided in the Java.util package. view the API as fol

First, a primer We go to the technology market for their own machine to add some luxury accessories, a lot of diyer like to find agents, because in the agents there is not only the quality assurance, but also the price and after-sales service will be much better. Customers through the agent to get what they want, but also enjoy the agents of the additional services, and manufacturers through agents to promote their products, and can be some sales ser

Turn from: The Dharma of slaveryhttp://blog.csdn.net/zhengzhb/article/details/7471978?reload#replydefinition: defines a one-to-many dependency between objects so that when each object changes state, all objects that depend on it are notified and updated automatically.Type: behavior class modeClass Diagram:This is often required in software systems: if the state of an object changes, certain objects associated with it change accordingly. For example, we want to

specific situations: 1. If that object is a very large picture, it takes a long time to be displayed, so when the picture is included in the document, you open the document using an editor or a browser, and the document must be opened quickly, and you can't wait for the big picture to finish, then you need to do a picture proxy instead of the real picture.2. If the object is on a remote server on the Internet, direct manipulation of the object because the network speed may be slow, then we can

The initial contact with the decorative design mode, has not understood the meaning of doing so, read a lot of information on the Internet, for the difference with the inheritance is not very clear analysis, until you see this blog: http://www.cnblogs.com/rookieFly-tdiitd/p/ 4914593.html This is a very clear explanation of the difference between the decorative design