如何理解Java设计分层模型里面的modelmoduledomainentity

发布时间:2025-05-23 03:54:50 发布人:远客网络

一、如何理解Java设计分层模型里面的model/module/domain/entity

1、domain是领域，就是做的项目面向什么业务，比如物流，金融，可能实际会范围小一些。

2、module是模块，一个大系统里分成几个小的模块

3、model是模型，基本上就是定义的各种能展现领域模型的类，比如物流里可能有仓库类，商品类，仓库存货记录类等。

4、entity是实体，模型中一种特殊的类，这种类每个实例都有一个唯一ID，可以被存储，从新取回重现。模型里还有可能有其他种类，比如值对象想enum，他属于model但不是实体

二、java(tm) plug-in 2 ssv helper是什么

1、通俗的来讲，Java(TM) plug-in 2 SSV Helper是浏览器运行时附带加载的一个插件，Java应用程序利用此插件来支持工具栏，BHO，浏览器栏等。它主要用于在浏览器上运行java小程序时构建java的运行时环境，打个比方，你家好比是浏览器，你需要把煤气灶打开来提供一个高温环境才能炒菜做饭，而这个插件就好比煤气灶。如果需要在Internet Explorer中查看浏览器中的Java应用程序和插件，您应该保留Java（tm）Plug-In 2 SSV Helper；如果你不需要在浏览器上运行java小程序（比如是你的个人电脑而不是公司的并且你不是做软件开发的等情况），完全可以禁用该插件的加载。

2、下面的内容您完全可以选择不看，但是我要是不加上，百度会给出提示：认证拒绝。这样我就没法提交答案。

3、Java is a programming language. You need something called the Java Runtime Environment to run programs written in Java. The Plugin is part of that. A small number of websites also use this. The Java Runtime Environment will appear in Programs and Features in the Control Panel and can be uninstalled from there. Unfortunately, there is a bug in the uninstallation that leaves the entry for the plugin in the Internet Explorer Manage Addons window after Java is uninstalled. This is harmless because the file has been deleted. To remove the entry in Manage Addons would require editing the Registry.

4、This bug has been known since at least 2008, but nothing seems to have been done about it.

5、The"SSV Helper" is not the main add-on for Java and we can still run Java applications from the Internet with it disabled. The question was what does this particular add-on do and the implications of disabling it.

6、The overwhelming number of near-useless, tautological replies to this question here and elsewhere is pretty disappointing.

7、Here is what I discovered, buried in this bug report on Sun's Java community:

8、"This object is responsible for a propagation of Java Plug-in settings from admin account to all regular(non admin) user accounts. In other words if SSVHelper is registered with IE then the only thing admin needs to do in order to switch from a new Java Plug-in to an old Java Plug-in is to run from a command line: ssvagent.exe-high-jpisetup-old or uncheck a checkbox"Enable the next generation Java Plug-n" in Java Control Panel. In both cases changes will be propagated to non admin user accounts."

9、Therefore, if you are not in a managed, Enterprise environment—as in, this is your own personal computer—then the SSVHelper Java Browser Helper Object does nothing useful for you, and can be safely disabled.