For Internal Use Only | P800 Smartphone |
| White Paper, May 2002 |
J2ME CLDC/MIDP
J2ME CLDC 1.0 (Java2 Micro Edition, Connected Limited Device Configuration, version 1.0) is an edition of Java aimed at small
MIDP (Mobile Information Device Profile) defines a programming API which has gained wide industry acceptance, and many MIDP compliant mobile phones are anticipated to come to market. A large number of applications for this environment is therefore to be expected.
The P800 supports this J2ME CLDC 1.0 / MIDP 1.0 environment. Applications may make use of the following services:
•Persistent storage (RecordStore class only – no access to the rest of the filing system)
•Display – full 276 x 208 (i.e. minus the application picker and status bar)
•Touch Screen
•Virtual Keyboard and Jog Dial (up, down, select) input
J2ME/CLDC uses a security model, often referred to as a sandbox. The sandbox includes a number of system components working together to ensure that untrusted applications cannot gain access to system resources.
J2ME |
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CLDC |
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Sandbox |
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| MIDP Application |
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| running on |
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| MIDP/CLDC/KVM | Internet |
| HTTP/ | Services and |
| Datagram | pages with |
| UIQ Virtual | response in HTML |
| Keyboard + | format |
| Jog Dial | Other networked |
JAR file | Persistent | devices (datagram |
resource | Storage | communication) |
MIDP applications can interact with arbitrary remote services that exist as a URL. Data may also be exchanged with remote devices that accept an HTTP or datagram connection.
Applications are typically downloaded from the mobile operator’s portal or the internet.
Applications are used in FO mode. When the flip closes, the instance of the Virtual Machine is not visible, but the user may return to the application by selecting it from the Application Launcher.
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