Those nouns in Java are explained!

1.JDO:

(Java Data object) is a new specification for Java object Persistence and a standardized API for accessing objects in a data warehouse. Role: For accessing objects in a data warehouse

2.JPA:

JPA is the abbreviation for Java Persistence API, the Chinese name Java Persistence Layer API, is a JDK 5.0 annotation or XML Description object-relational table mapping relationship, and the runtime of the entity object persisted into the database. Sun introduces the new JPA ORM specification for two reasons: one that simplifies the development of existing Java EE and Java SE applications; second, Sun wants to integrate ORM technology to achieve the world. 3.POJO: POJO (Plain ordinary Java object) Simple Java objects, actually is the ordinary JavaBeans, is to avoid and EJB confusion created by the abbreviation. the Pojo name is used to avoid confusion with EJBS, and the abbreviation is straightforward. There are classes of properties and their getter setter methods, no business logic, sometimes as VO (value-object) or DTO (Data Transform Object) to use. Of course, if you have a simple arithmetic attribute you can do it, but you don't allow business methods, and you can't carry methods like connection. 4.EJB: EJB is the Sun's Java EE server-side component model, and the design goal and core application is to deploy distributed applications. In simple terms, a program that has already been written (that is, a class) is packaged and placed on the server for execution. With the advantages of Java cross-platform, distributed systems deployed with EJB technology can be limited to specific platforms. EJB (Enterprise JavaBean) is part of the Java EE, which defines a standard for developing component-based enterprise multi-application applications. Features include network service support and core development tools (SDKs). In Java EE, Enterprise Java Beans (EJB) is called Java Business Bean, which is the core code of the kernel, namely the session bean, the entity bean Bean) and the message-driven bean (Messagedriven bean). After the launch of EJB3.0, entity beans were separately separated to form a new specification JPA.   5.struts: struts is an open source framework. Struts is used to help us reduce the time it takes to develop Web applications using the MVC design model. Struts is a good choice if we want to mix the benefits of Servlets and JSPs to build scalable applications. Struts is an open source project sponsored by the Apache Software Foundation (ASF). It was originally a subproject in the Jakarta Project and became the top-level project for ASF in March 2004. Using javaservlet/jsp technology, it realizes the application framework of MVC design pattern based on Java eeweb application, and it is a classic product in MVC Classic design pattern. [1] 6. JSF (Java Build framework): JavaServer Faces (JSF) is a standard framework for building Java WEB Applications (the JSR-127 standard defined by the Java Community Process). It provides a component-centric approach to building a user interface (UI) that simplifies the development of Java server-side applications. Driven by Java Community Process (JCP), it belongs to the technical specifications in Java EE 5 and is widely supported by vendors. 7.

Those nouns in Java are explained!