java pattern class

mode. Related issues and implementation1. If the number of prototypes that you need to create is not fixed, you can create a prototype manager that, before replicating the prototype object, will first view the client in the prototype managerWhether there is a prototype object that satisfies the condition, and if so, use it directly, if not, clone one, a prototype pattern called the registration form.2. There are two types of replication: deep copy a

), the data storage layer, they have to communicate through the interface.design pattern of three-layer structure③, in each layer, there are many small modules, a small module external should also be a whole, then a module external should also provide interface, other places need to use the function of this module, should pass this interface.2. Parameters and return values in the interface definition①, the interface must define the interface of the is

TAG: Structure operation ack Boolean send. com chain Assignment ExampleThe responsibility chain pattern of Java design patternThe last few days to review the Java exception handling, contact with the responsibility chain mode. In an enterprise application, the request from the foreground throws an exception in the background, the design of exception handling usua

, and we make a shallow copy of the object, then two objects will reference the same string.A deep copy is when a class has resources, and when the object of that class has a replication process, the resource is redistributed, and the process is a deep copy.Template methodThe prototype pattern is mainly used for object replication, and its core is the prototype

JAVA Design Pattern 1, Design Pattern 1 Design pattern is a set of summary of code Design experiences that are repeatedly used, known to most people, classified and catalogued. The design pattern is used to make code reusable, make it easier for others to understand, and ens

definition: defines a set of algorithms that encapsulate each algorithm and allow them to be interchangeable.Type: behavior class patternclass Diagram: The strategy pattern is the encapsulation of the algorithm, which encapsulates a series of algorithms into the corresponding classes, and these classes implement the same interface and can be replaced by each other. In the behavior

The 3rd chapter of the design pattern-template method pattern (Java implementation)　　"That, last time because my wife wanted to cook for me, so I did not finish to walk away 、、、 this one." This time, as before, the first benefits (factory method mode has been kicked off by the author). By the beauty of the abstract factory introduction of the application of the s

Iterator pattern definitionIterator mode (Iterator), which provides a way to sequentially access various elements in an aggregated object without exposing the object's internal representation .Role composition of the iterator pattern(1) Iterator Role (Iterator):Define the methods required to traverse the elements, generally there are three methods:Get the next element method next (),The method of determinin

, you must implement this interface. Numbergenerator Indicates the abstract class that generates values. Randomnumbergenerator Class that generates random numbers, inherited from numbergenerator Numberobserver A digital observer prints a changed number. Symbolobserver Symbol observer, print n symbols, and how many symbols are printed, determined by the accepte

Iterator pattern definitionIterator mode (Iterator), which provides a way to sequentially access various elements in an aggregated object without exposing the object's internal representation.Role composition of the iterator pattern(1) Iterator Role (Iterator): Defines the methods required to traverse elements, generally there are three ways to get the next element in the next (), to determine whether to tr

the randomness of the thread, Maybe T1 just went in to execute if control statement, this time, was T2 grabbed the CPU execution, this time, T2 began to execute, found that this time t is still null, so T2 also go in to execute if the statement of control, then there will be more than one object is created, so lazy type has a thread safety problem.Therefore, in the development we generally choose the A hungry man-type singleton mode without the thread safety problem.What kind of singleton mode

Servletexception { if (Servletname.equals ("servletName1")) {return new Service1 (); } else if (servletname.equals ("servletName2")) {return new Service2 (); } else{ throw new Servletexception ("No such servlet");}} The above factory class does not throw away the tedious if else, but the idea of using a simple factory still solves some problems. A simple factory is a very simple design patte