6 CHAPTER 1: Introducing Java Web Development
The Client Tier
The client tier is the top tier in a multitiered Java EE architecture; it consists of application clients
that make requests to the Java EE server, which is often located on a different machine. The server
processes the requests and returns a response to the client. An example of a client is a web browser
or a stand-alone application.
The Web Tier
The web tier consists of components that handle the interaction between clients and the business
tier. After receiving a request from the client, the web tier does the following:
- Collects input from the client
- Controls the flow of screens or pages on the client
- Maintains the state of data for a user’s session
- Obtains results from the components in the business tier
- Generates dynamic content in various formats to the client
As shown in Figure 1-2, a new Web Profile specification has been added in Java EE 7.^10 Table 1-
lists technologies included in the Web Profile specification. As mentioned earlier, the goal of Web
Profile is to allow developers to create web applications with the appropriate set of technologies.
Figure 1-3. Multitier architecture in Java
(^10) http://www.oracle.com/technetwork/java/javaee/tech/index.html