Accessing Remote Data on the Network - Beginning Java ME Platform - page 286

Table 12-1. Connection Schemes

URL Scheme Protocol GCF Connection Type Defined By Required

or Optional

btl2cap L2CAPConnection

Bluetooth JSR 82 Optional

datagram DatagramConnection

Datagram CLDC, CDC, and Optional

JSR 197 for J2SE

file FileConnection , File system access JSR 75† Optional

InputConnection

http HttpConnection HTTP MIDP 1.0,* Required

MIDP 2.0,**
Foundation Profile,***
and JSR 197 for Java SE

https HttpsConnection Secure HTTP MIDP 2.0** Required

comm CommConnection

Serial I/O MIDP 2.0** Optional

sms MessageConnection

SMS JSR 120, JSR 205 Optional

mms MessageConnection MMS JSR120, JSR 205 Optional

cbs MessageConnection Cell Broadcast JSR 120, JSR 205 Optional

Service (CBS)

apdu APDUConnection Application Protocol JSR 177†† Optional

Data Unit (APDU)

jcrmi JavaCardRMIConnection

Java Card Remote JSR 177†† Optional

Method Invocation

socket SocketConnection

Socket MIDP 2.0** Optional

serversocket ServerSocketConnection Socket MIDP 2.0** Optional

datagram UDPDatagramConnection UDP MIDP 2.0** Optional

*JSR 37 defines MIDP 1.0.
**JSR 118 defines MIDP 2.0.
***JSR 46 defines Foundation Profile 1.0; JSR 219 defines Foundation Profile 1.1.
†I discuss this in Chapter 7.
††I discuss this in Chapter 15.

From Table 12-1, you can see that not all Java ME platforms support even the most
common connection types. This is something you must keep in mind when designing
your applications. For example, it would do you little good to develop an application that
required the use of UDP datagrams for widespread deployment on legacy handsets that
probably run CLDC MIDP 1.0, because those handsets likely don't provide support for
the UDPDatagramConnection , and even some CLDC MIDP 2.0 handsets lack support for that
class. In general, it's safe to assume support for HTTP on any CLDC or CDC device;