Layers of the J2ME architecture

A small computing device has two components supplied by the original equipment manufacturer (OEM). These are classes and applications. OEM classes are used by the MIDP to access device-specific features such as sending and receiving messages and accessing device-specific persistent data. OEM applications are programs provided by the OEM, such as an address book. OEM applications can be accessed by the MIDP.

一个小型计算设备有原始设备提供商（OEM）提供的两个组件，分别是类库和应用软件。MIDP通过OEM类库访问设备独有特性，如发送和接收消息、访问设备相关的持久数据。OEM应用软件是OEM提供的一组程序，如地址通讯录。OEM应用软件可以被MIDP访问。

A word of caution: accessing OEM classes and OEM applications from the MIDP restricts the portability of a J2ME application since not all small computing device manufacturers use the same OEM classes or OEM applications.

注意：采用MIDP访问OEM类库和OEM程序会限制J2ME应用的可移植性，因为不是所有小型计算设备提供商都采用相同的OEM类库或应用软件。