1. J2EE related knowledge
1. Introduce the differences between J2EE, j2se, and j23. (1) J2EE (Java 2 Platform Enterprise Edition) is a system platform used to establish server applications, it is an open standard platform for developing, deploying, and managing multi-layer, web-based, server-centric, and component-based enterprise-level applications. (2) j2se (Java 2 platform) (3) J2EE (Java 2 platform) 2. Is J2EE a technology or a platform that provides those technologies. 3. What is application server? What functions and advantages does it have. 4. Briefly introduce the advantages and Principles of the connection pool. 5. web. role of XML 4. Other 1. web security considerations (Form Verification, browser basic verification, application security, SSL, code considerations) 2. A Brief Introduction to MVC. 3. Briefly introduce the XML. 4. Documentation and coding specifications 5. Paging and efficiency considerations in Java. 6. A brief introduction to structs. 7. How many common J2EE models do you know or have heard? And some opinions on the Design Model
Session Facade Pattern: Use sessionbean to access entitybean
Message Facade Pattern: asynchronous call
EJB Command pattern: replace sessionbean with command JavaBeans for Lightweight Access
Data transfer object Factory: Using DTO factory to simplify entitybean data provision features
Generic attribute access: the attibuteaccess interface simplifies entitybean data provision features
Business interface: Use Remote (local) interfaces and bean classes to implement the same interface and standardize business logic consistency
The design of the EJB architecture directly affects the system performance, scalability, maintainability, component reusability, and development efficiency. The more complex the project, the larger the project team, the more important the design is.
95. Please explain (or briefly describe) the terms commonly used in J2EE below)
Web Container: provides an environment for the application components (JSP and Servlet) in the container, so that JSP and servlet can directly interact with the environment variable interfaces in the container, so that you do not have to pay attention to other system problems. It is mainly implemented by Web servers. For example, tomcat, WebLogic, and websphere. The interface provided by the container strictly complies with the Web application standard in J2EE specifications. We call the web server that complies with the above standards the Web Container in J2EE.
EJB container: Enterprise Java Bean container. More industry-specific characteristics. It provides various management functions for the component EJB running in it. As long as the EJB meeting the J2EE specification is put into the container, it will be managed efficiently by the container immediately. In addition, system-level services can be obtained through ready-made interfaces. For example, mail service and transaction management.
JNDI :( Java Naming & Directory Interface) Java Naming directory service. The main function is to provide a directory system that allows applications from other places to leave their own indexes on it to quickly find and locate distributed applications.
JMS :( Java Message Service) Java Message Service. Communication between applications. Including point-to-point and broadcast.
JTA :( Java transaction API) Java transaction service. Provides various distributed transaction services. An application only needs to call the interfaces it provides.
JAF :( Java Action Framework) Java security authentication framework. Provides some security control frameworks. Developers can implement their own personalized security control policies through various deployment and customization.
RMI/IIOP :( Remote Method Invocation/Internet object request mediation protocol) They are mainly used to call services remotely. For example, if a program runs on a remote computer that provides the Stock Analysis Service, we can directly call it on a local computer. Of course, this requires certain specifications to communicate between heterogeneous systems. RMI is unique to Java. 8. Common design patterns? Describe the factory model.
There are 24 Design Patterns in Java:
Factory (factory mode), Builder (construction mode), factory method (Factory method mode ),
Prototype (original model mode), Singleton (Singleton mode), facade (facade mode ),
Adapter (adapter mode), bridge (Bridge Mode), composite (merging mode ),
Decorator, flyweight, proxy ),
Command (command mode), Interpreter (Interpreter mode), visitor (visitor mode ),
Iterator, mediator, memento ),
Observer (Observer mode), State (State mode), Strategy (Policy mode ),
Template Method (template method mode), chain of responsibleity (responsibility chain mode) j2eemvc (Model-View-controler)
Factory mode: The factory mode is a frequently used mode. Classes implemented based on the factory mode can generate instances of a class in a group based on the provided data, generally, this group of classes has a common abstract parent class that implements the same method, but these methods perform different operations on different data. First, you need to define a base class. The subclass of this class implements the methods in the base class through different methods. Define a factory class. The factory class can generate different subclass instances according to the conditions. After obtaining the subclass instance, developers can call the methods in the base class without having to consider which subclass instance is returned. 9. What is J2EE?
J2EEYesSunMultiple Layers proposed by the company(Multi-diered ),Distributed(Distributed ),Component-based(Component-Base)Enterprise-level application model(Enterpriese application model ).In such an application system, different components can be divided by function. These components can be on different computers and at the corresponding level.(Tier). Including the customer Layer(Clietn tier)Components, WebLayers and components, BusinessLayers and components,Enterprise Information System(EIS)Layer.
