Java EE reading notes

Read the Java Platform, Enterprise Edition:your first Cup:an Introduction to the Java EE Platform (https://docs.oracle.com/javae e/7/firstcup/) "notes.

Prepare to see "JavaEE7 Tutorial (https://docs.oracle.com/javaee/7/tutorial/)"

Enterprise applications: The Java EE platform is designed to help programmers create large-scale, multi-tiered, scalable, reliable, and secure network applications . This kind of application is called "Enterprise Application", the reason is called because this kind of application is used to solve the problem that big enterprise can encounter.

Tiered applications: In a multi-tiered application, the functionality of an application is cut into separate functional areas called layers. The composition of a multi-tiered application: Typically, a multi-tiered application consists of a client layer, a middle tier, and a data layer (the data layer is often called the Enterprise Information System layer). The middle tier is generally divided into the web layer and the business logic layer. The three-tier relationship is this: client-level clients make requests to the middle tier, which processes the client's requests while processing the application's data, permanently storing the application's data on the data layer. Web services: Web services and Web applications are not the same thing. There are currently two types of Web services in the Java domain:jax-rs:Java API for RESTful Web Services Jax-ws : Java API for XML Web Services shows the relationship between Web apps (Enterprise Apps) and Web services:Three-tier application deployment: The General client layer is a browser or a standalone application that runs on a separate machine; the middle tier consists of the Web layer and the business Logic layer, which runs on a separate machine; the data layer, also known as the Enterprise Information System layer, is generally run on a separate machine.

Focus on a data layer: The data layer is called the Enterprise Information System layer. The Enterprise Information System layer is typically made up of a database server, or an enterprise resource planning system, or a traditional data source, such as a mainframe (mainframe).

Java EE server: the Java EE server is a server application that implements the Java EE Platform API and provides standard Java EE services. Java EE servers are sometimes referred to as application servers because the application server provides application data to the client as if the Web server provided the Web page to the Web browser. The Java EE server contains several application components that correspond to the layers of the multi-tier application. Java EE servers serve a variety of application components in this form of containers. Containers in a Java EE server: A container is an interface between the underlying functionality and application components provided by the Java EE server to support the application components. The functionality of a container is defined by the server platform and has different containers for different application components. However, application servers allow different application components to work together in the same enterprise-level application to serve clients. Several containers are specifically described: Web container, EJB container, application client container. A Web container is an interface between a Web component and a Web server. The Web component may be a servlet or JSF. The Web container is responsible for managing the life cycle of the Web component, distributing the request to the application component, and providing the interface for the context data, such as the information currently requested. EJB container: The EJB container is an interface between Enterprise beans, and EJBS are used to provide business logic. The EJB container runs on the Java EE server. Application Client Container: The application client container is the interface between the Java EE application client and the Java EE server. The application client container runs on the client machine, which is the interface of the Java EE server components used by the client application and the clients application.

Java EE reading notes