j2ee 平台概述

最近测试关于j2ee的东西.以前从没有做过关于java和j2ee(me,se) 的.

关于j2ee,感觉还是比较复杂, 是multi-tiered ,同一个层内的多个功能模块之间降低耦合度,方便开发和维护.

可以部署多台j2ee server应用不同应用服务(分开部署模块）.

 

j2ee 平台主要是如下几个东西。

 

 

提供最基础的服务的就是 j2ee server。

 

相当于是地基。为下面的几个 container 提供服务。

 

Java EE Containers （感觉这个j2ee容器 ， 是直接嵌入在j2ee server里，融合在一起， 并为其他得模块之间提供接口和基础的功能）

Java EE containers are the interface between the component and the lower-level functionality provided by the Java EE platform to support that component. The functionality of the container is defined by the Java EE platform, and is different for each component type. Nonetheless, the Java EE server allows the different component types to work together to provide functionality in an enterprise application.

The Web Container（interface between web components and the web server.有了这个，你才能用java 的技术来生成webpage，供客户浏览）

The web container is the interface between web components and the web server. A web component can be a servlet, a JSP page, or a JavaServer Faces page. The container manages the component's lifecycle, dispatches requests to application components, and provides interfaces to context data, such as information about the current request.

The Application Client Container（这个是部署在客户端的。如果不是通过browser的方式和j2eeserver 交互，则需要客户端安装这个。）

The application client container is the interface between Java EE application clients, which are special Java applications that use Java EE server components, and the Java EE server. The application client container runs on the client machine, and is the gateway between the client application and the Java EE server components that the client uses.

The EJB Container（ interface between enterprise beans and the Java EE server ， 这样使用j2ee server的服务的客户就可以与ejb模块交互，这样ejb模块才能被别人调用。）

The EJB container is the interface between enterprise beans, which provide the business logic in a Java EE application, and the Java EE server. The EJB container runs on the Java EE server and manages the execution of an application's enterprise beans.